Big aux battery for overlanding?

[DbqDude]

Question, if Jeep thinks it's ok to add that little aux battery connected directly to the main battery, then why couldn't I extend heavy cables to the rear and just replace the aux battery with a full size one? Not lithium of course but a deep cycle agm. Even add an isolator like the old days so it doesn't drain the main when the engine is off. I know I can add a dc to dc charger like I've done on other builds but I don't want to this time. Shouldn't matter if its a smart alternator or not, right? I've already disconnected my aux anyway. Just curious as I wait til fall for my Lone Peak Overland camper to be built...

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[Mr._Bill]

Question, if Jeep thinks it's ok to add that little aux battery connected directly to the main battery, then why couldn't I extend heavy cables to the rear and just replace the aux battery with a full size one? Not lithium of course but a deep cycle agm. Even add an isolator like the old days so it doesn't drain the main when the engine is off. I know I can add a dc to dc charger like I've done on other builds but I don't want to this time. Shouldn't matter if its a smart alternator or not, right? I've already disconnected my aux anyway. Just curious as I wait til fall for my Lone Peak Overland camper to be built...

The Aux battery is installed to keep the computers and electronics stable during ESS events. It is paralleled together with the Main Battery, so it does provide some extra capacity. It is not intended to be used for anything else.

Just install a third battery in the back. Use a Smart Isolator to charge it. Warn sells a cable kit for connecting a winch that works great for a remote battery. It is essentially a DIY version of the Genesis dual battery kit. I added a 34m deep cycle battery and attached it to the frame behind the right rear wheel. I'm in the process of reinstalling it on my new truck. This time I'm going to try and run the cabling through the frame rail instead of zip tying it to the top.

https://www.jeepgladiatorforum.com/forum/threads/diy-dual-battery-setup.23232/

 

[ttn333]

Genesis makes a kit that replaces both stock batteries with 2 group 25s in the stock main battery location.. look at the 3:44 mark.

 

[Wolf Island Diver]

Question, if Jeep thinks it's ok to add that little aux battery connected directly to the main battery, then why couldn't I extend heavy cables to the rear and just replace the aux battery with a full size one? Not lithium of course but a deep cycle agm. Even add an isolator like the old days so it doesn't drain the main when the engine is off. I know I can add a dc to dc charger like I've done on other builds but I don't want to this time. Shouldn't matter if its a smart alternator or not, right? I've already disconnected my aux anyway. Just curious as I wait til fall for my Lone Peak Overland camper to be built...

Ignoring the complexities of the ESS system, you could technically do this in theory. The big aux battery would be in parallel when driving and you’d have to remember to isolated it when stopped. There’s a number of reasons not to.

1. It’s mostly pointless from an ESS standpoint. That system doesn’t need a big battery
2. Separation of concerns. The house battery system really needs to be separate. While major power drains are unlikely running a good quality 12v fridge, when driving you’re pulling from the same system that powers the vehicle which introduces risk. You have to remember to isolate the Aux when stopped or you may have a dead starting battery the next morning. A bad house battery or some other parasitic drain in your house power system can kill your starting battery and you may not realize it. You may have to winch and discharge the battery keeping your food cold
3. The house battery in an overlanding setup is really not the core of the system despite the fact that we sort of wire it, and thus tend to think of it that way. Operationally, solar is the core of the system. Without solar, you will find that a 100AH Lithium is not going to last long. With a 100W panel, the battery becomes a buffer. So you need solar and by the time you add solar to the starting/house combined system, al la carte, with a separate charge controller and isolator, you could have just gotten at DC-to-DC charger that includes a solar charge controller and will charges the house and isolates it and back charge the starting battery off solar too.
4. Lithium. The charging and discharging profiles for overlanding usage are not ideal for AGM batteries. Or maybe more accurately, Lithium is better. But more importantly, you can run different types of starting and house batteries with a DC-to-DC charger.
5. Monitoring. Your house battery needs to be monitored. It’s bad enough that you end up worrying about power. Not knowing how much capacity you have or your time left at current draw or time to fully charged is nerve racking. You could just assume “well I have two big batteries” but you really can’t because ones supposed to be for starting and maybe winching. You can add monitoring through shunts, but again the al la carte component method adds up to what a good DC-to-DC charge controller costs.
6. A real system doesn’t cost that much. Mine wasn’t much more than my Goal Zero. I have a Renogy system. The most expensive thing was the self-heating Lithium battery. A good AGM battery isn’t cheap either. You don’t need a RedArc Red Vision system for a truck unless it’s a camper conversion and I’d still probably go with Renogy. It’s monitoring is through an app. I have no complaints so far. You could buy a Renogy DCC50S for $269 at Amazon, and probably cheaper elsewhere. You can use it with and AGM or traditional lead acid to save money and spring for a Lithium when they go on sale. Now all you need is a solar panel and their Bluetooth module which is cheap. The DCC50S already has the solar charge controller.

The smart alternator issue is that modern alternators don’t always run. They shut off a various times to reduce load on the engine and save fuel. The result is that the vehicle is running but a steady 14V isn’t guaranteed like old school alternators. DC-to-DC chargers work around this by including a sensor connected to an ignition circuit. If this sensor detects voltage, the truck is running and the DC-to-DC charger starts drawing power from the starting battery. However if the truck is off but voltage at the starting battery exceeds the normal trigger, it will also start charging. For Renogy I think it’s 12.8 V or 13.something. This condition only exists if the starting battery is charging. I discovered this plugging my starting battery into a battery tender. My Renogy DCC50S will turn on and charge the house battery too off of the same source. It’s a poor man’s shore power, but it’s good for topping off both batteries in winter, when I remove my solar panel.

 

[DbqDude]

Ignoring the complexities of the ESS system, you could technically do this in theory. The big aux battery would be in parallel when driving and you’d have to remember to isolated it when stopped. There’s a number of reasons not to.

1. It’s mostly pointless from an ESS standpoint. That system doesn’t need a big battery
2. Separation of concerns. The house battery system really needs to be separate. While major power drains are unlikely running a good quality 12v fridge, when driving you’re pulling from the same system that powers the vehicle which introduces risk. You have to remember to isolate the Aux when stopped or you may have a dead starting battery the next morning. A bad house battery or some other parasitic drain in your house power system can kill your starting battery and you may not realize it. You may have to winch and discharge the battery keeping your food cold
3. The house battery in an overlanding setup is really not the core of the system despite the fact that we sort of wire it, and thus tend to think of it that way. Operationally, solar is the core of the system. Without solar, you will find that a 100AH Lithium is not going to last long. With a 100W panel, the battery becomes a buffer. So you need solar and by the time you add solar to the starting/house combined system, al la carte, with a separate charge controller and isolator, you could have just gotten at DC-to-DC charger that includes a solar charge controller and will charges the house and isolates it and back charge the starting battery off solar too.
4. Lithium. The charging and discharging profiles for overlanding usage are not ideal for AGM batteries. Or maybe more accurately, Lithium is better. But more importantly, you can run different types of starting and house batteries with a DC-to-DC charger.
5. Monitoring. Your house battery needs to be monitored. It’s bad enough that you end up worrying about power. Not knowing how much capacity you have or your time left at current draw or time to fully charged is nerve racking. You could just assume “well I have two big batteries” but you really can’t because ones supposed to be for starting and maybe winching. You can add monitoring through shunts, but again the al la carte component method adds up to what a good DC-to-DC charge controller costs.
6. A real system doesn’t cost that much. Mine wasn’t much more than my Goal Zero. I have a Renogy system. The most expensive thing was the self-heating Lithium battery. A good AGM battery isn’t cheap either. You don’t need a RedArc Red Vision system for a truck unless it’s a camper conversion and I’d still probably go with Renogy. It’s monitoring is through an app. I have no complaints so far. You could buy a Renogy DCC50S for $269 at Amazon, and probably cheaper elsewhere. You can use it with and AGM or traditional lead acid to save money and spring for a Lithium when they go on sale. Now all you need is a solar panel and their Bluetooth module which is cheap. The DCC50S already has the solar charge controller.

The smart alternator issue is that modern alternators don’t always run. They shut off a various times to reduce load on the engine and save fuel. The result is that the vehicle is running but a steady 14V isn’t guaranteed like old school alternators. DC-to-DC chargers work around this by including a sensor connected to an ignition circuit. If this sensor detects voltage, the truck is running and the DC-to-DC charger starts drawing power from the starting battery. However if the truck is off but voltage at the starting battery exceeds the normal trigger, it will also start charging. For Renogy I think it’s 12.8 V or 13.something. This condition only exists if the starting battery is charging. I discovered this plugging my starting battery into a battery tender. My Renogy DCC50S will turn on and charge the house battery too off of the same source. It’s a poor man’s shore power, but it’s good for topping off both batteries in winter, when I remove my solar panel.

I have the ESS disabled so that's not my concern at all. When I say big aux battery it's not meant to replace the tiny worthless one for the purpose jeep intended. I refer to aux as in house battery or in the normal old school sense of the word before this ess crap. I run my fridge in the cab off of an ecoflow delta 2 as well as any 110v needs. The aux/house battery is really just for led lights and maybe phone charging when the camper arrives. For now I've replaced the starter agm battery with an Odyssey Extreme 27f and then connected the 150ah deep cycle agm diy power box to my 30amp trailer pin. So far it charges it up quickly and has a resting voltage around 13v. I could also just use my NOCO genius 10 charger from the 400w bed outlet to charge the aux battery. I decided to skip the actual extending of the aux cables from the factory and just deleted that tiny battery all together. I realize when plugged into the 7 way that the house and starter are still connected but I also have a voltage meter on my diy power box to monitor. It doesn't move just using led lights for a couple days so I'm comfortable with it.

 

[chorky]

Mmmmm..... I have some comments in red here.

Ignoring the complexities of the ESS system, you could technically do this in theory. The big aux battery would be in parallel when driving and you’d have to remember to isolated it when stopped. There’s a number of reasons not to.

1. It’s mostly pointless from an ESS standpoint. That system doesn’t need a big battery
2. Separation of concerns. The house battery system really needs to be separate. While major power drains are unlikely running a good quality 12v fridge, when driving you’re pulling from the same system that powers the vehicle which introduces risk. You have to remember to isolate the Aux when stopped or you may have a dead starting battery the next morning. A bad house battery or some other parasitic drain in your house power system can kill your starting battery and you may not realize it. You may have to winch and discharge the battery keeping your food cold. I think a lot of people fail to understand this. The ESS system is not at all the same as a typical 'house' battery setup. Trying to use the ESS battery connectors tied to a different 'house' battery will leave one disappointed as you already pointed out.
3. The house battery in an overlanding setup is really not the core of the system despite the fact that we sort of wire it, and thus tend to think of it that way. Operationally, solar is the core of the system. Without solar, you will find that a 100AH Lithium is not going to last long. With a 100W panel, the battery becomes a buffer. So you need solar and by the time you add solar to the starting/house combined system, al la carte, with a separate charge controller and isolator, you could have just gotten at DC-to-DC charger that includes a solar charge controller and will charges the house and isolates it and back charge the starting battery off solar too. The house battery is definitely the core of the system. The majority of people who have a 'house' battery do not have solar. Solar is a great addition, but without the battery, the whole system is pointless. It's like saying a car doesn't need a battery since it has an alternator. Sure maybe with 500w of solar a person can run their fridge, but when the sun goes down or the clouds come, it doesn't work. The battery is an absolute necessary requirement for a 'house' system, making it the core component.
4. Lithium. The charging and discharging profiles for overlanding usage are not ideal for AGM batteries. Or maybe more accurately, Lithium is better. But more importantly, you can run different types of starting and house batteries with a DC-to-DC charger. I disagree significantly here and want to offer a different opinion/perspective, but will preface by saying lithium is not a 'bad' option, it is great tech, but is not necessarily the 'best'. Everyone is on the lithium bandwagon and it is not the end-all-be-all answer to overlanding. I run AGM batteries specifically by choice for a reason, and they operate perfectly. They are significantly cheaper - half the cost. Of course the negative is they are double the weight. However, they work when temps are below freezing and do not require I remove them during the winter or when it gets cold. Lithium will not function (rather it can be discharged but not charged safely), and is dangerous, at cold temperatures. So if you have a 100ah of lithium, once that is used up over a 24 hour trip, you better get back home to charge that battery in the house as it will not charge if cold - and the self heaters some batteries have are not sufficient for temps in the teens or below. As well, it is dangerous at high temperatures. Lithium is much more finicky. It flat out requires a special charging system whereas AGM batteries can be directly charged by your vehicle alternator, and isolated when parked via a solenoid or battery combiner - WAY more simple. They are much more conducive to overlanding environments, temperature variances, rough bouncing roads, washboard road vibrations, etc. than lithium is with the current technology. An AGM setup is also significantly cheaper - like a third of the cost of lithium or less. Also, to crush the fallacy that most people have about operational ability, my AGM batteries can safely run to a SOC/DOD of 30%/70% respectively. Which is about the same as most lithium batteries. Yeah they advertise a draw down of 100% but that can damage them depending on their specific design. Also, at a DOD of 70% for my AGM batteries, it allows for 500 cycles. To reach a DOD of 70%, I would have to run all my accessories for 3 full days, thats 72 hours, with NO charging. No driving, no solar, no shore power, no nothing, just sitting at camp relaxing. The reality is most people will be lucky to go camping more than 40 days out of a year. Doing the math, assuming 500 FULL cycles for maximum draw of these AGM batteries, (also assuming again 72 hours of no charging, no solar, etc...) that gives you 13 years worth of cycling. The batteries will never last that long anyway. So justifying only discharging to 50% or saying one has to have lithium for long life is ignoring the maths, and theres no need to maximize the 4000 cycles by only discharging to 80% SOC - its pointless past 500 cycles unless you literally cycle it 100% every day and live in said vehicle.
5. Monitoring. Your house battery needs to be monitored. It’s bad enough that you end up worrying about power. Not knowing how much capacity you have or your time left at current draw or time to fully charged is nerve racking. You could just assume “well I have two big batteries” but you really can’t because ones supposed to be for starting and maybe winching. You can add monitoring through shunts, but again the al la carte component method adds up to what a good DC-to-DC charge controller costs. Good points and I have always suggested in every one of my posts that everyone MUST do an energy audit. Not knowing what your consumption rates are and battery size needs are is just dumb and will either put someone in a situation of insufficient battery capacity, thus needing to spend more money, or having spent twice as much as actually needed on a way overkill system. Energy audits are critical. it would be like buying any random jeep off the lot without even looking at what package it is or accessories it has and just 'assuming' it will work for your needs. Not everyone needs a Rubicon, and rock crawlers would be pissed to not have sway disco's or a 4:1 transfer case. But, a person can build a really good AGM based system without a DC/DC charger. A batter combiner or solenoid costs less than half that of most DC/DC chargers. The only thing really needed is to ensure one disconnects the main vehicle battery from the house battery when doing a hard winch pull or when parked for the night.
6. A real system doesn’t cost that much. Mine wasn’t much more than my Goal Zero. I have a Renogy system. The most expensive thing was the self-heating Lithium battery. A good AGM battery isn’t cheap either. You don’t need a RedArc Red Vision system for a truck unless it’s a camper conversion and I’d still probably go with Renogy. It’s monitoring is through an app. I have no complaints so far. You could buy a Renogy DCC50S for $269 at Amazon, and probably cheaper elsewhere. You can use it with and AGM or traditional lead acid to save money and spring for a Lithium when they go on sale. Now all you need is a solar panel and their Bluetooth module which is cheap. The DCC50S already has the solar charge controller.

The smart alternator issue is that modern alternators don’t always run. They shut off a various times to reduce load on the engine and save fuel. The result is that the vehicle is running but a steady 14V isn’t guaranteed like old school alternators. DC-to-DC chargers work around this by including a sensor connected to an ignition circuit. If this sensor detects voltage, the truck is running and the DC-to-DC charger starts drawing power from the starting battery. However if the truck is off but voltage at the starting battery exceeds the normal trigger, it will also start charging. For Renogy I think it’s 12.8 V or 13.something. This condition only exists if the starting battery is charging. I discovered this plugging my starting battery into a battery tender. My Renogy DCC50S will turn on and charge the house battery too off of the same source. It’s a poor man’s shore power, but it’s good for topping off both batteries in winter, when I remove my solar panel. This is the biggest most important bit of information I think a lot of people also overlook. Since I have the genesis system (modified) my system still pushes enough voltage to charge the batteries. but, if a person builds their own system with only a solenoid, that likely wont happen and it is likely to under-charge the house battery. I think some real world testing would be needed to verify this. There is a lot of talk about it, but I dont think anyone has actually tested it to truth it out. That is though where a DC/DC is advantageous. However, since I often am running higher than 13v, my batteries are always receiving a charge. Another consideration while discussing charging is wires. It's critical to use the right wire size for the application. A 50a DC/DC charger can easily want 65 amps to charge at a 50 amp rate. Assuming the only purpose for that particular wire run is to charge a battery, a person would not want to use 10ga wire. Similarly is a setup for AGM directly connected to the main battery via a combiner. My particular batteries can accept a max charge of 35 amps each, which having two means 70a. I also run my compressor and other items off of the same 4ga wiring, so there is a safety built in there to not overload the wire as well as conscious thought of making sure the solenoid is in an open state prior to doing a hard winch pull.

This is just my .02. I dont mean to discount or talk bad about a lithium system or a persons choice to use lithium, but there is a lot of bad info out there and unnecessary 'hate' for AGM without valid or true reasoning IMO. Lithium is great in certain applications. AGM is also great in other applications. It's just a personal choice. But this bandwagon of lithium being the only solution is just not true.



Woah - there is a lot going on here. Comments in red

I have the ESS disabled so that's not my concern at all. When I say big aux battery it's not meant to replace the tiny worthless one for the purpose jeep intended. I refer to aux as in house battery or in the normal old school sense of the word before this ess crap. I run my fridge in the cab off of an ecoflow delta 2 as well as any 110v needs. The aux/house battery is really just for led lights and maybe phone charging when the camper arrives. With such a low power need, theres really no reason to even have another aux battery when you can run all of that off your ecoflow. Thats just adding unnecessary complications. Stick with one 'house' system you don't need 2 different house systems. For now I've replaced the starter agm battery with an Odyssey Extreme 27f and then connected the 150ah deep cycle Just because it says 150ah does not mean you can use all 150ah. Different battery designs have different tolerances. Mine are designed to allow a 70% DOD (actually I think it's 80% now that I think of it) without causing battery damage. However the golden standard for most AGM batteries is to not go below 30% DOD. You need to do some homework on the specific battery design and tolerances agm diy power box to my 30amp trailer pin. This is probably ok for theat particular battery but as I discussed above you really need to know the specifics of your battery. That little 150ah battery might have the ability to accept 60a. So if it is fully discharged by accident, and it tries to pull 60a, you're gonna blow a fuse or burn up wiring. So far it charges it up quickly and has a resting voltage around 13v. I could also just use my NOCO genius 10 charger from the 400w bed outlet to charge the aux battery. So it is connected to your trailer 30a pin, and also the bed via a NOCO charger? Ok, aside from other things this is not necessary. You are now taking a 12v DC system, converting it to AC via the bed mounted inverter, and then converting it back into 12V DC via the NOCO to charge the battery? That is terribly inefficient and wasting energy. Not to mention, since the battery is receiving a charge when the engine is running via the 30a trailer pin, the NOCO charger is likely on 'standby' and not even charging anything at all anyway, that or you are pushing feedback back into the main vehicle via the 30a trailer pin. Theres a lot of potential dangers and problems doing both of these at the same time. The better way to go is run a dedicated wire from the main battery to the aux battery via a solenoid or combiner. Much more simple. Or, you can continue to use the trailer 30a charge pin IF you make sure the battery will never draw more than 30a through that. Or you can use ONLY the NOCO charger (which is the least efficient method). Get rid of the whole bed inverter deal. Maybe consider using that NOCO to plug the battery into your house when at home to keep it topped off but don't do both of these at the same time thats really not a good idea. I decided to skip the actual extending of the aux cables from the factory and just deleted that tiny battery all together. I realize when plugged into the 7 way that the house and starter are still connected but I also have a voltage meter on my diy power box to monitor. It doesn't move just using led lights for a couple days so I'm comfortable with it.

 

[DbqDude]

Mmmmm..... I have some comments in red here.




This is just my .02. I dont mean to discount or talk bad about a lithium system or a persons choice to use lithium, but there is a lot of bad info out there and unnecessary 'hate' for AGM without valid or true reasoning IMO. Lithium is great in certain applications. AGM is also great in other applications. It's just a personal choice. But this bandwagon of lithium being the only solution is just not true.



Woah - there is a lot going on here. Comments in red

You seem to assume a lot that wasn't said. Maybe you could re-read what was said and you wouldn't have to type a book in red like a teacher. I am very aware of proper usage of different battery types and depth of discharge. I have built many off grid systems with solar, dc-dc, lifepo4, agm, converters, inverters, blah, blah, blah. My starter battery alone is rated for deep discharge while still having starter burst ability. Not that I would use it in that way but it's there with 195ah RC as well. The Rubicon also has a 250amp alternator.

As far as lithium goes, it's great for a vehicle house battery as it's half the weight, does not off gas, and can be almost completely depleted without damage. (some even completely) I will eventually swap my deep cycle agm out for a lifepo4 but I really see no need until the agm no longer works. I swap this agm power box between my enclosed trailer and my truck bed as needed. At this point my power needs are very small for both applications and ~75ah out of that battery is plenty. If you think an agm will draw 60amps that's interesting. The 7 pin is fused at 30amps and used for trailer and rv batteries all the time in most all tow vehicles.

There are also plenty of youtube rv electrical guys that have tested charging lifepo4 directly from the 7 pin with a smart alternator and it works fine as well. Again, maybe not ideal, but it works fine.

This thread was asking about the use of the factory aux leads to charge a house battery. It would seem the factory aux system does indeed suck for that purpose so I stated that I went a different much more simple route with an optional way to charge as well. And it suites my needs just fine. Cheers.

 

[Wolf Island Diver]

Mmmmm..... I have some comments in red here.




This is just my .02. I dont mean to discount or talk bad about a lithium system or a persons choice to use lithium, but there is a lot of bad info out there and unnecessary 'hate' for AGM without valid or true reasoning IMO. Lithium is great in certain applications. AGM is also great in other applications. It's just a personal choice. But this bandwagon of lithium being the only solution is just not true.



Woah - there is a lot going on here. Comments in red

Have you actually ever used a Lithium setup overlanding? I’ve used AGM for years camping and overlanding and boating and fishing, etc. Everyone is jumping on the LiFEPO bandwagon because it’s far superior tech in almost every way. It also keeps getting better and cheaper.

My whole Lithium set up was about $1200, with 300w of solar charging. A DCC50S is $250. It just works, the setup is simple, everything is automatic. For any extended period Solar is absolutely the heart of the system. When on full solar in my system, the battery is just a pass through for solar power.

Lithium Advantages:

• Take a significantly greater number of charge/discharge cycles
• They charge significantly faster
• Far greater depth of discharge. They don’t experience voltage drops like AGMs do at deep discharges, even deep cycle batteries.
• Much higher energy density
• Lower weight
• Smaller size
• Much longer lifespan
• Lower self depletion rate when sitting
• lower total lifecycle cost (better value over the long term)

The disadvantage of Lithium is performance in temperature extremes. A good LiFePO house battery needs either a heating blanket or a self heating feature and they don’t like extreme high heat either. Although AGM batteries don’t like extremes either, they’re way more forgiving in this area. My batteries self heating feature has worked flawlessly.

I don’t understand your comment about 24 hours and having to go home with Lithium. With my single 100AH battery and a single 100w solar panel, I can stay out indefinitely. I rarely deploy the other panels unless is cloudy. The battery usually doesn’t drop below 70% overnight running a fridge, lights, running power to my tent, powering/charging devices and running an inverter. I’ve run a projector and Nintendo switch off of the system for hours as well, and I don’t think I dropped below 50%. My only limitation is food and water. I can charge the Lithium from 75% to full in about 15-20 minutes off the alternator. In the back of the bed, I haven’t experienced any issues in winter. Now, I don’t typically camp below freezing, but I have and the system worked fine. If you live in Alaska or somewhere where it’s cold all the time, then certainly it’s a different calculus. I’ve been able to work from the road for a week or more off of this single 100AH battery.

Saying that AGM batteries are better is like saying Apple needs to go back to Intel processors. The data just doesn’t back that up.

I do only run AGM starting batteries. I haven’t jumped on the Lithium starting battery wagon because in that application, I don’t see that you gain a lot from lithium and the engine compartment of my truck is like a blast furnace.

 

[DbqDude]

Have you actually ever used a Lithium setup overlanding? I’ve used AGM for years camping and overlanding and boating and fishing, etc. Everyone is jumping on the LiFEPO bandwagon because it’s far superior tech in almost every way. It also keeps getting better and cheaper.

My whole Lithium set up was about $1200, with 300w of solar charging. A DCC50S is $250. It just works, the setup is simple, everything is automatic. For any extended period Solar is absolutely the heart of the system. When on full solar in my system, the battery is just a pass through for solar power.

Lithium Advantages:

• Take a significantly greater number of charge/discharge cycles
• They charge significantly faster
• Far greater depth of discharge. They don’t experience voltage drops like AGMs do at deep discharges, even deep cycle batteries.
• Much higher energy density
• Lower weight
• Smaller size
• Much longer lifespan
• Lower self depletion rate when sitting
• lower total lifecycle cost (better value over the long term)

The disadvantage of Lithium is performance in temperature extremes. A good LiFePO house battery needs either a heating blanket or a self heating feature and they don’t like extreme high heat either. Although AGM batteries don’t like extremes either, they’re way more forgiving in this area. My batteries self heating feature has worked flawlessly.

I don’t understand your comment about 24 hours and having to go home with Lithium. With my single 100AH battery and a single 100w solar panel, I can stay out indefinitely. I rarely deploy the other panels unless is cloudy. The battery usually doesn’t drop below 70% overnight running a fridge, lights, running power to my tent, powering/charging devices and running an inverter. I’ve run a projector and Nintendo switch off of the system for hours as well, and I don’t think I dropped below 50%. My only limitation is food and water. I can charge the Lithium from 75% to full in about 15-20 minutes off the alternator. In the back of the bed, I haven’t experienced any issues in winter. Now, I don’t typically camp below freezing, but I have and the system worked fine. If you live in Alaska or somewhere where it’s cold all the time, then certainly it’s a different calculus. I’ve been able to work from the road for a week or more off of this single 100AH battery.

Saying that AGM batteries are better is like saying Apple needs to go back to Intel processors. The data just doesn’t back that up.

I do only run AGM starting batteries. I haven’t jumped on the Lithium starting battery wagon because in that application, I don’t see that you gain a lot from lithium and the engine compartment of my truck is like a blast furnace.

100% agree. I would be using a heated lifepo4 in my diy battery power box but I already had this group 27 150ah agm from our cabin and it was almost new with less than 2 cycles on it. I'm looking forward to replacing it since it's in a portable box and weighs over 65 pounds.

 

[Wolf Island Diver]

Another thing to keep in mind. I’ve never charged my house battery. Meaning, I’ve never had to go home and charge it or plug it into a tender or charger. The solar panel keeps it topped off. It’s always at 100% unless I’m overlanding and running a bunch of loads off of it. In summer the solar panel keeps the starting battery charged too. I only use my NOCO 10 in winter, when I’ve removed the solar panel to keep the DEF tank heater powered. Still the DCC50S will trickle charge the LifePO from the NOCO and will top it off after 10 minutes of driving. So the system is always ready to go 365 days a year with zero work from me. It’s like a bug out rig.

Here’s my thread on my setup.

https://www.jeepgladiatorforum.com/forum/threads/renogy-lifepo-house-dual-battery-install.71866/

 

[Wolf Island Diver]

100% agree. I would be using a heated lifepo4 in my diy battery power box but I already had this group 27 150ah agm from our cabin and it was almost new with less than 2 cycles on it. I'm looking forward to replacing it since it's in a portable box and weighs over 65 pounds.

Yeah, and I don’t think AGMs are bad, just that Lithium is better for house battery needs. I wouldn’t throw away good AGMs and go buy LifePos, though. I would choose Lithium if I was building from scratch and didn’t have have batteries already.

 

[DbqDude]

Yeah, and I don’t think AGMs are bad, just that Lithium is better for house battery needs. I wouldn’t throw away good AGMs and go buy LifePos, though. I would choose Lithium if I was building from scratch and didn’t have have batteries already.

Have you seen the new Renogy 50amp dc-dc/solar charger? It's waterproof and has a much higher solar voltage input capacity now. But I don't think you can buy it just yet in the states. If I decide to build out my Lone Peak I'll most likely use that as an all in one device for charging. It will even reverse charge to the starter battery from solar when the house is full. And can be mounted under the hood eliminating running the solar into the camper and not use long runs of large awg cable for the supply side. Pair that with a heated bluetooth lifepo4 and you have a simple very usable system with no need for additional monitoring devices. I don't really need an inverter for 120v while overlanding. The only time I use it on my Delta 2 is for hot water kettle instead of using the stove. And the truck has the 400w inverter to charge my gmrs hand helds.

 

[chorky]

You seem to assume a lot that wasn't said. Maybe you could re-read what was said and you wouldn't have to type a book in red like a teacher. I am very aware of proper usage of different battery types and depth of discharge. I have built many off grid systems with solar, dc-dc, lifepo4, agm, converters, inverters, blah, blah, blah. My starter battery alone is rated for deep discharge while still having starter burst ability. Not that I would use it in that way but it's there with 195ah RC as well. The Rubicon also has a 250amp alternator.

As far as lithium goes, it's great for a vehicle house battery as it's half the weight, does not off gas, and can be almost completely depleted without damage. (some even completely) I will eventually swap my deep cycle agm out for a lifepo4 but I really see no need until the agm no longer works. I swap this agm power box between my enclosed trailer and my truck bed as needed. At this point my power needs are very small for both applications and ~75ah out of that battery is plenty. If you think an agm will draw 60amps that's interesting. The 7 pin is fused at 30amps and used for trailer and rv batteries all the time in most all tow vehicles.

There are also plenty of youtube rv electrical guys that have tested charging lifepo4 directly from the 7 pin with a smart alternator and it works fine as well. Again, maybe not ideal, but it works fine.

This thread was asking about the use of the factory aux leads to charge a house battery. It would seem the factory aux system does indeed suck for that purpose so I stated that I went a different much more simple route with an optional way to charge as well. And it suites my needs just fine. Cheers.

The 'teacher notes' was to make it easier to understand what I was responding to, not to come across as a 'teacher'. I dont know about you but I appreciate it when a community of people weigh in on a question that I ask as it helps me make the right decision for me based on experiences of others. What I dont like is when a handful of people end up saying "this product is the best ever product and nothing else will ever work as good as this" because that is ignorant to a particular person's use case. Good luck with whatever you choose.

Have you actually ever used a Lithium setup overlanding? I’ve used AGM for years camping and overlanding and boating and fishing, etc. Everyone is jumping on the LiFEPO bandwagon because it’s far superior tech in almost every way. It also keeps getting better and cheaper.

My whole Lithium set up was about $1200, with 300w of solar charging. A DCC50S is $250. It just works, the setup is simple, everything is automatic. For any extended period Solar is absolutely the heart of the system. When on full solar in my system, the battery is just a pass through for solar power.

Lithium Advantages:

• Take a significantly greater number of charge/discharge cycles
• They charge significantly faster
• Far greater depth of discharge. They don’t experience voltage drops like AGMs do at deep discharges, even deep cycle batteries.
• Much higher energy density
• Lower weight
• Smaller size
• Much longer lifespan
• Lower self depletion rate when sitting
• lower total lifecycle cost (better value over the long term)

The disadvantage of Lithium is performance in temperature extremes. A good LiFePO house battery needs either a heating blanket or a self heating feature and they don’t like extreme high heat either. Although AGM batteries don’t like extremes either, they’re way more forgiving in this area. My batteries self heating feature has worked flawlessly.

I don’t understand your comment about 24 hours and having to go home with Lithium. With my single 100AH battery and a single 100w solar panel, I can stay out indefinitely. I rarely deploy the other panels unless is cloudy. The battery usually doesn’t drop below 70% overnight running a fridge, lights, running power to my tent, powering/charging devices and running an inverter. My only limitation is food and water. I can charge the Lithium from 75% to full in about 15-20 minutes off the alternator. In the back of the bed, I haven’t experienced any issues in winter. Now, I don’t typically camp below freezing, but I have and the system worked fine. If you live in Alaska or somewhere where it’s cold all the time, then certainly it’s a different calculus. I’ve been able to work from the road for a week or more off of this single 100AH battery.

Saying that AGM batteries are better is like saying Apple needs to go back to Intel processors. The data just doesn’t back that up.

I do only run AGM starting batteries. I haven’t jumped on the Lithium starting battery wagon because in that application, I don’t see that you gain a lot from lithium and the engine compartment of my truck is like a blast furnace.

There is an aspect that is pretty important that hardly anyone discusses with this kind of topic. You somewhat brought it up though. "The disadvantage of Lithium is performance in temperature extremes." I dont understand why almost everyone fails to ever consider this. Temperature extremes is a factor that for some may be of critical importance. Where I live, it consistently gets to -25 in the winter. Just a few months ago we had 4 days of -30 with day time high temps of -20. A lithium battery, even just sitting outside, does not like that one bit, neither does an AGM. But at least an AGM can safely receive a trickle charge/maintenance at that temperature, whereas most lithium batteries cannot. Even with self heaters, it wouldn't be enough. And with self heaters, the battery would discharge itself, but with it so cold it wont accept a charge. It would have to be inside an insulated and heated box to be used. I dont go camping in that weather at all either, but I do like to have my batteries on a charger/maintainer especially when it is that cold. But then that insulated heated box would be a disadvantage in the summer of course. Requiring a person to constantly be messing with said batteries. That is a totally doable situation, never did I say it was not. But it is something people should be thinking about and considering. As you said AGM is much more forgiving in that regard. Maybe the OP doesn't care, but maybe they do care. But it's something people, especially those without any experience, need to be aware of.

As for solar and my 24 hour comment. Most people I think consider a 24 hour time period when trying to calculate electrical usage and battery capacity needs. Yes again you mentioned something you have. Does the OP have solar? Maybe.... Is solar a guarantee? No. What about those in washing, Oregon, Alaska? They might have tree canopy so thick solar doesn't even work. So just assuming that because solar allows a person to be out indefinitely is not considering all factors - which could result in someone loosing their food if using a fridge.

I also never flat out said "AGM is better". It is better in some situations, yes, but lithium is also better in other situations. It is entirely situational dependent. If I did say somewhere flat out that "AGM is better in all situations no matter what" please point that out to me.

As for starting batteries. AGM is the ONLY kind of battery you can legit use in the Gladiator. This has been discussed a lot. In fact there was a guy recently who went agains all recommendations of people who know a lot more than I do and he still put a lithium in as a replacement for his main starting battery because the vendor he purchased from flat out lied to him (or they dont even know themselves). What happened? In a few weeks he was left stranded and had to get towed back home. It is well documented that lithium and AGM batteries require different charging profiles. Will it work for a period of time? Sure. Is it the correct thing to do? Well I guess that is a personal choice. But clearly he got stranded, and others on other forums have also gone against recommendations with other vehicles, some old school without a smart alternator, and they also were left stranded. So it seems pretty clear to me that a vehicle designed for a AGM starting battery must keep AGM as a starting battery. Even just 'tacking on' a lithium battery and directly connecting it to the AGM electrical system via the trailer charge plug like the OP said he did - it might work for a period of time, maybe even for a good long while. But it is taking a risk of unknown consequences. Maybe in the future AGM and lithium batteries will be able to accept the same charging profiles or maybe they will be able to utilize different chart profile types. That would be really awesome and a game changer for a lot of applications.

Look. I'm not trying to sound like the 'bad guy' here. But every single time one of these battery topics come up, time and time and time again people fail to consider ALL options. In order to pick the best solution for a particular individual, their use case, their experience, their price range, their needs. ALL options must be laid on the table and discussed. Otherwise, it is doing a big disservice to that person who is leaning on a community to learn and understand. That is why I always try to bring up these other options. Lithium is great tech. but it is not the end all be all solution in every situation, and assuming so is a failure to considering other options.

 

[DbqDude]

The 'teacher notes' was to make it easier to understand what I was responding to, not to come across as a 'teacher'. I dont know about you but I appreciate it when a community of people weigh in on a question that I ask as it helps me make the right decision for me based on experiences of others. What I dont like is when a handful of people end up saying "this product is the best ever product and nothing else will ever work as good as this" because that is ignorant to a particular person's use case. Good luck with whatever you choose.





There is an aspect that is pretty important that hardly anyone discusses with this kind of topic. You somewhat brought it up though. "The disadvantage of Lithium is performance in temperature extremes." I dont understand why almost everyone fails to ever consider this. Temperature extremes is a factor that for some may be of critical importance. Where I live, it consistently gets to -25 in the winter. Just a few months ago we had 4 days of -30 with day time high temps of -20. A lithium battery, even just sitting outside, does not like that one bit, neither does an AGM. But at least an AGM can safely receive a trickle charge/maintenance at that temperature, whereas most lithium batteries cannot. Even with self heaters, it wouldn't be enough. And with self heaters, the battery would discharge itself, but with it so cold it wont accept a charge. It would have to be inside an insulated and heated box to be used. I dont go camping in that weather at all either, but I do like to have my batteries on a charger/maintainer especially when it is that cold. But then that insulated heated box would be a disadvantage in the summer of course. Requiring a person to constantly be messing with said batteries. That is a totally doable situation, never did I say it was not. But it is something people should be thinking about and considering. As you said AGM is much more forgiving in that regard. Maybe the OP doesn't care, but maybe they do care. But it's something people, especially those without any experience, need to be aware of.

As for solar and my 24 hour comment. Most people I think consider a 24 hour time period when trying to calculate electrical usage and battery capacity needs. Yes again you mentioned something you have. Does the OP have solar? Maybe.... Is solar a guarantee? No. What about those in washing, Oregon, Alaska? They might have tree canopy so thick solar doesn't even work. So just assuming that because solar allows a person to be out indefinitely is not considering all factors - which could result in someone loosing their food if using a fridge.

I also never flat out said "AGM is better". It is better in some situations, yes, but lithium is also better in other situations. It is entirely situational dependent. If I did say somewhere flat out that "AGM is better in all situations no matter what" please point that out to me.

As for starting batteries. AGM is the ONLY kind of battery you can legit use in the Gladiator. This has been discussed a lot. In fact there was a guy recently who went agains all recommendations of people who know a lot more than I do and he still put a lithium in as a replacement for his main starting battery because the vendor he purchased from flat out lied to him (or they dont even know themselves). What happened? In a few weeks he was left stranded and had to get towed back home. It is well documented that lithium and AGM batteries require different charging profiles. Will it work for a period of time? Sure. Is it the correct thing to do? Well I guess that is a personal choice. But clearly he got stranded, and others on other forums have also gone against recommendations with other vehicles, some old school without a smart alternator, and they also were left stranded. So it seems pretty clear to me that a vehicle designed for a AGM starting battery must keep AGM as a starting battery. Even just 'tacking on' a lithium battery and directly connecting it to the AGM electrical system via the trailer charge plug like the OP said he did - it might work for a period of time, maybe even for a good long while. But it is taking a risk of unknown consequences. Maybe in the future AGM and lithium batteries will be able to accept the same charging profiles or maybe they will be able to utilize different chart profile types. That would be really awesome and a game changer for a lot of applications.

Look. I'm not trying to sound like the 'bad guy' here. But every single time one of these battery topics come up, time and time and time again people fail to consider ALL options. In order to pick the best solution for a particular individual, their use case, their experience, their price range, their needs. ALL options must be laid on the table and discussed. Otherwise, it is doing a big disservice to that person who is leaning on a community to learn and understand. That is why I always try to bring up these other options. Lithium is great tech. but it is not the end all be all solution in every situation, and assuming so is a failure to considering other options.

Just one note, heated lithiums do not self deplete as the heating pads are powered only from incoming power of 10 amps or more and the bms disconects the charging circuit until the battery reaches ~40f. And folks even build them into insulated battery enclosures so they can maintain temp easier. In your case for sure lithium would be difficult. I think most people using it in those types of extreme climates will keep those batteries in the cab or heated living area. And honestly if it's that cold I'm not overlanding and the batteries of any type are removed and stored in my heated shop. Cheers

 

[Wolf Island Diver]

The 'teacher notes' was to make it easier to understand what I was responding to, not to come across as a 'teacher'. I dont know about you but I appreciate it when a community of people weigh in on a question that I ask as it helps me make the right decision for me based on experiences of others. What I dont like is when a handful of people end up saying "this product is the best ever product and nothing else will ever work as good as this" because that is ignorant to a particular person's use case. Good luck with whatever you choose.





There is an aspect that is pretty important that hardly anyone discusses with this kind of topic. You somewhat brought it up though. "The disadvantage of Lithium is performance in temperature extremes." I dont understand why almost everyone fails to ever consider this. Temperature extremes is a factor that for some may be of critical importance. Where I live, it consistently gets to -25 in the winter. Just a few months ago we had 4 days of -30 with day time high temps of -20. A lithium battery, even just sitting outside, does not like that one bit, neither does an AGM. But at least an AGM can safely receive a trickle charge/maintenance at that temperature, whereas most lithium batteries cannot. Even with self heaters, it wouldn't be enough. And with self heaters, the battery would discharge itself, but with it so cold it wont accept a charge. It would have to be inside an insulated and heated box to be used. I dont go camping in that weather at all either, but I do like to have my batteries on a charger/maintainer especially when it is that cold. But then that insulated heated box would be a disadvantage in the summer of course. Requiring a person to constantly be messing with said batteries. That is a totally doable situation, never did I say it was not. But it is something people should be thinking about and considering. As you said AGM is much more forgiving in that regard. Maybe the OP doesn't care, but maybe they do care. But it's something people, especially those without any experience, need to be aware of.

As for solar and my 24 hour comment. Most people I think consider a 24 hour time period when trying to calculate electrical usage and battery capacity needs. Yes again you mentioned something you have. Does the OP have solar? Maybe.... Is solar a guarantee? No. What about those in washing, Oregon, Alaska? They might have tree canopy so thick solar doesn't even work. So just assuming that because solar allows a person to be out indefinitely is not considering all factors - which could result in someone loosing their food if using a fridge.

I also never flat out said "AGM is better". It is better in some situations, yes, but lithium is also better in other situations. It is entirely situational dependent. If I did say somewhere flat out that "AGM is better in all situations no matter what" please point that out to me.

As for starting batteries. AGM is the ONLY kind of battery you can legit use in the Gladiator. This has been discussed a lot. In fact there was a guy recently who went agains all recommendations of people who know a lot more than I do and he still put a lithium in as a replacement for his main starting battery because the vendor he purchased from flat out lied to him (or they dont even know themselves). What happened? In a few weeks he was left stranded and had to get towed back home. It is well documented that lithium and AGM batteries require different charging profiles. Will it work for a period of time? Sure. Is it the correct thing to do? Well I guess that is a personal choice. But clearly he got stranded, and others on other forums have also gone against recommendations with other vehicles, some old school without a smart alternator, and they also were left stranded. So it seems pretty clear to me that a vehicle designed for a AGM starting battery must keep AGM as a starting battery. Even just 'tacking on' a lithium battery and directly connecting it to the AGM electrical system via the trailer charge plug like the OP said he did - it might work for a period of time, maybe even for a good long while. But it is taking a risk of unknown consequences. Maybe in the future AGM and lithium batteries will be able to accept the same charging profiles or maybe they will be able to utilize different chart profile types. That would be really awesome and a game changer for a lot of applications.

Look. I'm not trying to sound like the 'bad guy' here. But every single time one of these battery topics come up, time and time and time again people fail to consider ALL options. In order to pick the best solution for a particular individual, their use case, their experience, their price range, their needs. ALL options must be laid on the table and discussed. Otherwise, it is doing a big disservice to that person who is leaning on a community to learn and understand. That is why I always try to bring up these other options. Lithium is great tech. but it is not the end all be all solution in every situation, and assuming so is a failure to considering other options.

Most self-heating Lithium batteries are designed to charge safely down to -20° C. I’ve never had any issues in below freezing temps although I’ve never camped at -20° C and have zero desire to. I’m going to venture a guess that 95% of people aren’t overlanding in those temps or even below freezing most of the time, but even so a self-heating battery, insulated battery boxes, etc solve that problem. Anyone camping below freezing is already having to make other accommodations for things like water freezing/expansion, heating, etc. I think the Lithium battery is only one issue.

As for solar, the entry cost is around $150 for a 100W panel. I’ve got some chinesium folding panels that will put out maybe 75-100w and take up about the same space as a large laptop. To me solar is a no brainer. But there’s no Lithium-solar requirement. If anything you’re more apt to need solar charging if you run AGM because you can’t go as deep into the batteries capacity without voltage drop. You simply have less useable capacity with the same AH AGM battery.

Where LiFePO batteries shine with solar is that they charge really fast. So a small solar panel can easily keep a 100AH battery topped off even while being used for things like a fridge. With a decent solar setup on a small camper like a Patriot, etc and 200AH worth of Lithium you can run these new efficient portable AC units. Several of them come with Lithium battery packs.

In my setup, sitting at the beach in the sun in 95°+ temps, my panel will keep the fridge at 25° easily without using the battery at all. It’s only when I’m under a tree canopy for 3-4 days that I start to deplete my battery in summer. But again, with the lithiums, a short ride down the trail on alternator power and it’s recharged again.

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