chorky
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This thread is to discuss overall the Genesis system, and is due to a question in post # 23,573 found here - https://www.jeepgladiatorforum.com/...ning-no-politics.23705/page-1572#post-1132511 by @azmojave
So a quick recap on the Genesis just to lay a foundation for those unaware.
The Genesis system (https://www.genesisoffroad.com/gen3-jt-dual-battery-kit) is a dual battery kit for the JT Gladiator (and they offer for other vehicles also) that eliminates the factory motorcycle style aux battery, and also replaces the primary group 31 battery with two group 25 batteries. In this system, one battery remains the primary vehicle starting battery, and the second is an auxiliary battery. They are connected together via a high amp battery combiner (basically a solenoid that doesn't require constant voltage to close). The programming of the system keeps the two batteries combined when voltages are at or above 12.7, and separates them when voltage of one battery drops below 12.7. This allows the aux battery to power things like a fridge, etc... when the engine is off so you don't discharge the starting battery, and then recombine when the engine is on to recharge the aux - similarly to how the factory aux system works actually. The aux battery connections also include a really nice buss bar that you can connect accessories to. And if you choose the G-Screen you can see battery voltage status in the cab, manually connect/disconnect the combiner, and have a color indicator of the combiner status. This system requires you remove the entire factory battery tray, and replace it with their new unit which is conducive for mounting two group 25 batteries, the combiner, and aux battery lugs. This system does require you reattach the factory aux battery + cable to the primary battery + terminal.
My build thread also includes discussion on the Genesis system, as well as this post - https://www.jeepgladiatorforum.com/forum/threads/genesis-batteries-lets-do-some-math.62165/ and here https://www.jeepgladiatorforum.com/forum/threads/three-roads-to-house-power.66527/#post-1091515
Here is a short list of some pro's and con's to the system
PRO
CON
So I myself got this system because at the time my summer plans included weekend trips with one maybe two nights per trip - this is an important aspect to driving me toward the Genesis system. I also absolutely HATED the idea of the factory aux battery in its designated location, as well as the fact it was tiny and even existed. I have no needs or desires for the ESS system, and that small battery, for me, was only a liability. I also wanted a clean install of whatever system was chosen - and the Genesis provided that. I first did an energy audit to calculate a realistic estimate of power I would need. This is a HUGE variable because different people may have massively different needs. So an energy audit is ALWAYS warranted, even if one thinks their needs are low, include things that might happen in the future just to see where you are currently estimated as compared to what the future potential is.
The genesis system is really slick - it takes old school tech (just linking two AGM batteries together, with the option to disconnect them via a solenoid) and merges it with more modern tech (G-screen, and automated disconnecting at specified voltages). It is well designed and thought out - although this version I have is Gen 3, whereas the previous versions are kinda - ugly to be honest. I would not have purchased the previous versions. This old school tech is not necessarily the 'best' way to go about things, but it is tried and true with known long term issues. One of the major long term issues is reduced battery life. Charging batteries of different capacities or voltage levels can reduce their lifespan - however, likely the battery lifespan is already lower than optimum due to other environmental factors (cold winter temperatures). This is also not to say that any type of dual battery system is 'better' than another. There are a huge number of variables that may make one system style optimum over another - but the term 'best' does not apply here because there is really no 'best' style.
Ok so that out of the way let's get into some more details.
This system uses OEM style AGM batteries. There are SO many on the market. After doing a lot of research myself, I think that full river offers some really excellent options. This system allowed me to retain use of these AGM batteries which is important for me for two reasons. 1) rough roads, nothing new to off-roaders, and 2) cold winter temps. This second reason really is the primary reason for me. After having done an energy audit, and knowing what winter temperatures in my particular location tend to be, I really wanted to stay away from lithium. The reason being is lithium does NOT like cold temperatures. Sure you can utilize their power, but recharging below 40 degrees is not recommended unless there is a method to heat the batteries (which some now offer self heating options). Another reason at the time was cost. The Genesis system came in at a total cost of about $1,600. This included both batteries, the new tray, the guts of the system (combiner and wiring), and the G-screen. It was certainly not cheap by any means - but cheaper than a lot of lithium systems, granted many of those systems had higher capacities. I also was driven this way because according to my energy audit, one 64ah aux battery (included in the system) was sufficient for 24 hours worth of camping with no energy input. And with some solar input, or short drives, that could be extended - and of course for long drives the battery would recharge giving yet another 24 hours.
Now lets dive into some details specific to MY situation
Install of the system went fairly well although I did have a couple of hiccups but nothing major. Once it was installed, the function was exactly as designed. However, here is where I started having issues. My refrigerator, even with overestimating the needed battery capacity, was not able to be ran for a full 24 hours. This was with ambient temperatures outside between 55 and 65 (on some warm days last month), and the freezer set to 20 degrees with the fridge at its pre-determined 34 degrees. This also was with an Engle 45 combi fridge, which typically draws significantly less power than competitors. Even using their specs, and math, I found that real world was not optimum. Granted, I had nothing in the fridge so it was working a little harder than it needed to.
So by this measure, there was no way to run other future items for a night of camping if the fridge alone didn't run a full 24 hours. One caveat - and it is a biggie, is I was also calculating and monitoring to make sure that the aux 64ah battery did not drop below 70% SOC - and there were some other power assumptions that were wrong, so my initial power audit was inaccurate. Now 70% SOC is a well known number for AGM (and led in general) batteries. That is the number to which dropping below, will quickly reduce battery longevity at a significant rate. But, this is also 'old' knowledge. I did end up contacting full river, and found that the recommended DOD level for their FT series batteries is 80% (20% SOC). However, upon reading the specifications, this equates to a more desired 1,000 battery cycles before replacement is necessary. So, I thought - well what would battery longevity be at 500 cycles as 500 cycles equate to being able to drain said battery to 80% DOD. And the answer is 16 years. 16 years of life considering a 'cycle' is draining said battery to X percent. And given I can expect to truly 'cycle' a battery up to 31 times per year (I just calculated the total number of expected days of camping per year), that equates to 16 years. We all know batteries don't last that long anyway.
So, my math needed adjusting. No surprise, after all a lot of educated estimations need to be made here. With the newly adjusted number down to 30% SOC (for a conservative factor) and some increased numbers for amp draw, duty cycles, and ah/hour used, I realized that the 64ah aux battery would not suffice - this was a major estimation mistake. Maybe for 18 hours worth, but not 24. On top of this, at about this time, I realized some opportunities arose to go on three 5-7 day trips this summer - another major decision maker. Thinking that my summers would be restricted to 1-2 nighters quickly changed. And these 5-7 day trips could include up to a full day of not moving, and possibly driving only 4-6 hours the next day. This meant the 64 ah battery was not large enough.
Considering a TON of options, I landed on picking up another AGM battery. I had already considered using the factory group 31 jeep battery in the bed since it was now un-used, but since I needed more power, I opted for a full river DC series 115ah battery. After chatting with an electrical engineer there, I decided to take the risk of pairing a deep cycle AGM at double the capacity, with the 64ah starting battery under the hood. According to their electrical engineer, mixing these two battery capacities despite them also being designed for different uses, will not make a significant and noticeable life reduction. And given the previous math of 500 cycles equaling 16 years, I would be willing to accept a drop to even 250 cycles - which is still a longer mathematically time than the batteries will realistically last anyway. And, after chatting with him I also realized that their FT series of batteries (which includes the 64ah aux) is capable of 80% DOD without significant and immediate damage. So, simply adding in a DC 115ah battery was 'safe'. The one concern I had was how fast that battery would try to recharge, and if my 4ga wire going to the bed for everything would be up to the task. And again, their battery specs suggest a max charge rate of 45 amps, to which my 4ga wire is fused at 100a. So, should be safe.
Now - revisiting the math, with the 64ah FT and 115ah DC batteries combined giving a total of 179ah capacity, with a conservative 70% DOD for a usable amount of 125.3 amps, separated from the FT 64ah starting battery, I can expect up to 1.48 days of use. This was acceptable. Although at the cost of adding a 70 pound battery at $450 to the bed - but pale in comparison to a $2,000 200ah lithium battery.
Now, is when we get into the discussion of "would I do the Genesis system again"
And the answer is a frustratingly "it depends - and I don't really know"
So let's explore quickly what a lithium system would look like now that the Genesis system is explained.
I effectively have currently 125.3 usable ah of battery. So, similarly, I would need 200ah of lithium to be 'equal'. I say equal because I have not seen lithium batteries offered at 64ah, so two 100ah batteries would make it easier to compare despite that adding 21ah of capacity. Lithium batteries are also good to 80% DOD, but my math will calculate to 70% to try and be similar to the current AGM setup. So, except for that 21ah, it is even enough to compare. Looking at my math calculations, 200ah of lithium power would equate to 1.65 days of use. A little more than the 1.48 days with the current AGM setup. But, considering both systems are 'allowed' to a SOC of 30% they are pretty close. Two huge benefits of lithium are 1) it recharges quickly and easily, 2) weight - they are significantly lighter. 200ah of lithium can easily be 70% lighter than the same capacity in AGM. So that is a pretty significant factor especially as these rigs get filled with more and more stuff. I currently have about 170 pounds worth of battery between the two under the hood and the additional DC in the bed.
But, the cost goes up
For example, one self heated 200ah lithium I just looked at is $1,900 bucks. And you still need, at the minimum, a DC/DC charger for which RedArc offers a very basic option that can charge at a 20a rate and accept a solar input, which costs $375. This would take 8 hours to recharge at said 20 ah rate. Or with a more robust 50 amp system it would take only 3.2 hours - however, a 50 amp system can easily cost $800 bucks not to mention needing more robust wire than I currently have, and a more advanced system that people gravitate to is about $1,500. So for a good 200ah lithium system you are looking at a minimum of $2,700. And you still need more components - wire, switches, etc. However considering in my specific system it is designed to be 100% modular, I can easily buy just the battery and DC/DC and make it function the same as it is now. So those other component costs are negligible. By comparison, by adding the third battery in the bed, the Genesis system (excluding the same electrical stuff that is needed for the fridge, switch, etc..) came in at about $2,100. The Genesis itself was $1,600, then adding a FR DC series 115ah battery at a little under 500 bucks brings it to just over $2,000.
There is still a problem though
With temperatures. Let me explain. AGM batteries are fine with temps. Of course overheating them is bad like with any, but for cold temps, they have to be literally frozen (which mean they would be close to depleted) or in some crazy -50 degree temp to have issues recharging (according to their electrical engineer). I dont think anybody would be camping then... Anyway, lithium is much more sensitive to temperatures. Really, charging them below 40 degrees is not good. So most of the self heating batteries turn on their heating element at 40, or is it 35... eh anyway those have a cool function. But here is the problem with that. It uses power. Right? So if you calculated your needs and found that you need 200ah of capacity, well you need additional capacity now to factor in the self heating function. So suddenly the $1,900 battery suddenly jumps to probably something like $2,400 bucks. So more cost. More cost to ensure you don't loose ah capacity for your 200ah need. Now we also need to consider when one is not camping. If your truck (like me) is sitting at home for 2 weeks in -25 degree temps in the winter, one of two things happen. 1) you pull the batteries and bring them inside and place on a battery tender, or 2) you plug them into a battery tender when outside - making sure said tender provides enough amperage to not let the batteries drain when their self heating function turns on. Option 1 for me is a no go. For me the whole point is to make a system that does not need constant loading/unloading.. I also do not have a garage. My jeep is already plugged in for a 15a CTEK charger/tender to maintain the start battery, because sitting for 14 days or more/or less at -25 degrees will cause battery charge loss. So now I need two plugs going to the jeep? I'm sure that there is a way to, oh I dont' know, have the DC/DC charger turn on when the tender for the AGM batteries is functional - but now were adding more complications....and more money.
The verdict
It is still out - honestly. Because there are SO many compromises, and one compromise of one system means X is needed or lost, while a compromise of the other system means XX is needed or lost. For example, the charging/tender example just given. I will say I like the current setup of AGM batteries because it (in theory) is enough power to do what I need. But I really DO NOT like the weight. It is an excessive amount of weight, and weight for me is already a major concern - fully loaded I am over axle weights. So going lithium could mean reducing weight easily by 75 pounds, maybe more. But at the cost of $$$$ and more complexity. I like the idea of lithium because of the relative fast recharge rate, and the light weight - but I really don't want to spend $3,000 on a lithium system when I already have spent about 2K on the current.
So what really needs to happen, for me, now, is to test the current system. I need more data points, and I already have the current system installed and working. I need to know how long the fridge will actually last - this coming weekend we supposedly are going to have temps in the high 60's, so I should be able to get a better feel for temps and run time as compared to trying to test when it's only 40 out which is not realistic. I also need to see charge rates. I really don't know what to expect, aside from documented specifications, what amp draw the aux batteries will have when depleted and how fast/slow they will recharge. Will they only draw 50 amps for maybe an hour? Or will they try to draw 200 amps and blow my fuse? (that is an exaduration of course). But that matters, because the 4ga wire that goes to the bed to run my fridge, is the same wire that would recharge the additional battery in the bed, and also the same wire that would be used to run the ARB dual air compressor. So if I start the engine, drive back to the highway, and need to air up while at the same time charging that battery in the bed, I can easily pull 100 amps or more depending on how much power that battery wants to take. I 'think' it will be ok, but only testing and checking temps of the wire with a laser gun will verify. And also, how long will it take to recharge? Will that 115ah battery in the bed recharge to 100% in 4 hours? Or will it require a 16 hour drive, or sitting overnight on the CTEK 15a charger to fully recharge? And how will that recharge rate affect camping? Obviously if it recharges in 4 hours, I can go for a drive and be good for camping for another 24 hours. If it needs 16 hours, then there is going to be a problem as it would mean I realistically only have just over a day's worth of camping before it needs to sit on the charger - because driving 16 hours every 24 hours is not feasible. But again, what is my use case? Which is the most important factor - are these three 5-7 day trips going to happen every year, or just this summer alone? What about the other 1 night camping trips where the current battery amount is sufficient (by calculation).
These are all questions that need answering in order to determine and decide would I do it again. And if anyone has answers to those questions I am all ears.
To sum it up
If you have the money, and don't live where I live and experience sub zero temps for 4 months at a time in winter, then going lithium is clearly the winner - simply due to it's weight, and relatively short recharge time compared to AGM. However, if you live in Montana or somewhere else that gets very cold, don't want to constantly remove the batteries from the truck in winter, or have a heated garage, or don't have the money for lithium and don't care about the weight - then yes I would do the system again.
Looking back - I would try and find a way to charge both AGM and lithium batteries at the same time with one on board charger (like how my CTEK is currently) from one extension cord. If I could find a way to make that work, then I would have deleted the factory aux, put in a full river full throttle group 31 in replacement of the factory MOPAR group 31 under the hood, and found a suitable 200ah lithium/LiFePo4 for the bed to be paired with a 50a DC/DC and upgrade from 4ga wire running to the bed to 2ga wire. The really tough situation for me specifically is the winter temperatures - and not wanting to be unloading batteries all the time.
I certainly hope this helps a few folks understand the pro's and con's of the Genesis and helps them decide which way is best for them. There is no 'best' answer because each option has its own compromises and benefits.
So a quick recap on the Genesis just to lay a foundation for those unaware.
The Genesis system (https://www.genesisoffroad.com/gen3-jt-dual-battery-kit) is a dual battery kit for the JT Gladiator (and they offer for other vehicles also) that eliminates the factory motorcycle style aux battery, and also replaces the primary group 31 battery with two group 25 batteries. In this system, one battery remains the primary vehicle starting battery, and the second is an auxiliary battery. They are connected together via a high amp battery combiner (basically a solenoid that doesn't require constant voltage to close). The programming of the system keeps the two batteries combined when voltages are at or above 12.7, and separates them when voltage of one battery drops below 12.7. This allows the aux battery to power things like a fridge, etc... when the engine is off so you don't discharge the starting battery, and then recombine when the engine is on to recharge the aux - similarly to how the factory aux system works actually. The aux battery connections also include a really nice buss bar that you can connect accessories to. And if you choose the G-Screen you can see battery voltage status in the cab, manually connect/disconnect the combiner, and have a color indicator of the combiner status. This system requires you remove the entire factory battery tray, and replace it with their new unit which is conducive for mounting two group 25 batteries, the combiner, and aux battery lugs. This system does require you reattach the factory aux battery + cable to the primary battery + terminal.
My build thread also includes discussion on the Genesis system, as well as this post - https://www.jeepgladiatorforum.com/forum/threads/genesis-batteries-lets-do-some-math.62165/ and here https://www.jeepgladiatorforum.com/forum/threads/three-roads-to-house-power.66527/#post-1091515
Here is a short list of some pro's and con's to the system
PRO
- removes the factory aux battery from the equation
- is a clean install with everything you need to work
- provides a system for a aux battery that is separated from the main battery to prevent main battery drain
- think of accessories like fridge, water pump, etc...
- has built in lug's to make easy mounting of accessory cables
- allows use of AGM batteries which work well in cold rough environments
CON
- requires removal of factory battery tray and PDC (for those who are unaware this could be problematic if precautions are not taken)
- uses two group 25 batteries (relatively small)
- additional weight up front (each battery approx 50 pounds)
- may require more batteries depending on needs
- requires use of AGM batteries which are heavier and less capacity typically than lithium options
So I myself got this system because at the time my summer plans included weekend trips with one maybe two nights per trip - this is an important aspect to driving me toward the Genesis system. I also absolutely HATED the idea of the factory aux battery in its designated location, as well as the fact it was tiny and even existed. I have no needs or desires for the ESS system, and that small battery, for me, was only a liability. I also wanted a clean install of whatever system was chosen - and the Genesis provided that. I first did an energy audit to calculate a realistic estimate of power I would need. This is a HUGE variable because different people may have massively different needs. So an energy audit is ALWAYS warranted, even if one thinks their needs are low, include things that might happen in the future just to see where you are currently estimated as compared to what the future potential is.
The genesis system is really slick - it takes old school tech (just linking two AGM batteries together, with the option to disconnect them via a solenoid) and merges it with more modern tech (G-screen, and automated disconnecting at specified voltages). It is well designed and thought out - although this version I have is Gen 3, whereas the previous versions are kinda - ugly to be honest. I would not have purchased the previous versions. This old school tech is not necessarily the 'best' way to go about things, but it is tried and true with known long term issues. One of the major long term issues is reduced battery life. Charging batteries of different capacities or voltage levels can reduce their lifespan - however, likely the battery lifespan is already lower than optimum due to other environmental factors (cold winter temperatures). This is also not to say that any type of dual battery system is 'better' than another. There are a huge number of variables that may make one system style optimum over another - but the term 'best' does not apply here because there is really no 'best' style.
Ok so that out of the way let's get into some more details.
This system uses OEM style AGM batteries. There are SO many on the market. After doing a lot of research myself, I think that full river offers some really excellent options. This system allowed me to retain use of these AGM batteries which is important for me for two reasons. 1) rough roads, nothing new to off-roaders, and 2) cold winter temps. This second reason really is the primary reason for me. After having done an energy audit, and knowing what winter temperatures in my particular location tend to be, I really wanted to stay away from lithium. The reason being is lithium does NOT like cold temperatures. Sure you can utilize their power, but recharging below 40 degrees is not recommended unless there is a method to heat the batteries (which some now offer self heating options). Another reason at the time was cost. The Genesis system came in at a total cost of about $1,600. This included both batteries, the new tray, the guts of the system (combiner and wiring), and the G-screen. It was certainly not cheap by any means - but cheaper than a lot of lithium systems, granted many of those systems had higher capacities. I also was driven this way because according to my energy audit, one 64ah aux battery (included in the system) was sufficient for 24 hours worth of camping with no energy input. And with some solar input, or short drives, that could be extended - and of course for long drives the battery would recharge giving yet another 24 hours.
Now lets dive into some details specific to MY situation
Install of the system went fairly well although I did have a couple of hiccups but nothing major. Once it was installed, the function was exactly as designed. However, here is where I started having issues. My refrigerator, even with overestimating the needed battery capacity, was not able to be ran for a full 24 hours. This was with ambient temperatures outside between 55 and 65 (on some warm days last month), and the freezer set to 20 degrees with the fridge at its pre-determined 34 degrees. This also was with an Engle 45 combi fridge, which typically draws significantly less power than competitors. Even using their specs, and math, I found that real world was not optimum. Granted, I had nothing in the fridge so it was working a little harder than it needed to.
So by this measure, there was no way to run other future items for a night of camping if the fridge alone didn't run a full 24 hours. One caveat - and it is a biggie, is I was also calculating and monitoring to make sure that the aux 64ah battery did not drop below 70% SOC - and there were some other power assumptions that were wrong, so my initial power audit was inaccurate. Now 70% SOC is a well known number for AGM (and led in general) batteries. That is the number to which dropping below, will quickly reduce battery longevity at a significant rate. But, this is also 'old' knowledge. I did end up contacting full river, and found that the recommended DOD level for their FT series batteries is 80% (20% SOC). However, upon reading the specifications, this equates to a more desired 1,000 battery cycles before replacement is necessary. So, I thought - well what would battery longevity be at 500 cycles as 500 cycles equate to being able to drain said battery to 80% DOD. And the answer is 16 years. 16 years of life considering a 'cycle' is draining said battery to X percent. And given I can expect to truly 'cycle' a battery up to 31 times per year (I just calculated the total number of expected days of camping per year), that equates to 16 years. We all know batteries don't last that long anyway.
So, my math needed adjusting. No surprise, after all a lot of educated estimations need to be made here. With the newly adjusted number down to 30% SOC (for a conservative factor) and some increased numbers for amp draw, duty cycles, and ah/hour used, I realized that the 64ah aux battery would not suffice - this was a major estimation mistake. Maybe for 18 hours worth, but not 24. On top of this, at about this time, I realized some opportunities arose to go on three 5-7 day trips this summer - another major decision maker. Thinking that my summers would be restricted to 1-2 nighters quickly changed. And these 5-7 day trips could include up to a full day of not moving, and possibly driving only 4-6 hours the next day. This meant the 64 ah battery was not large enough.
Considering a TON of options, I landed on picking up another AGM battery. I had already considered using the factory group 31 jeep battery in the bed since it was now un-used, but since I needed more power, I opted for a full river DC series 115ah battery. After chatting with an electrical engineer there, I decided to take the risk of pairing a deep cycle AGM at double the capacity, with the 64ah starting battery under the hood. According to their electrical engineer, mixing these two battery capacities despite them also being designed for different uses, will not make a significant and noticeable life reduction. And given the previous math of 500 cycles equaling 16 years, I would be willing to accept a drop to even 250 cycles - which is still a longer mathematically time than the batteries will realistically last anyway. And, after chatting with him I also realized that their FT series of batteries (which includes the 64ah aux) is capable of 80% DOD without significant and immediate damage. So, simply adding in a DC 115ah battery was 'safe'. The one concern I had was how fast that battery would try to recharge, and if my 4ga wire going to the bed for everything would be up to the task. And again, their battery specs suggest a max charge rate of 45 amps, to which my 4ga wire is fused at 100a. So, should be safe.
Now - revisiting the math, with the 64ah FT and 115ah DC batteries combined giving a total of 179ah capacity, with a conservative 70% DOD for a usable amount of 125.3 amps, separated from the FT 64ah starting battery, I can expect up to 1.48 days of use. This was acceptable. Although at the cost of adding a 70 pound battery at $450 to the bed - but pale in comparison to a $2,000 200ah lithium battery.
Now, is when we get into the discussion of "would I do the Genesis system again"
And the answer is a frustratingly "it depends - and I don't really know"
So let's explore quickly what a lithium system would look like now that the Genesis system is explained.
I effectively have currently 125.3 usable ah of battery. So, similarly, I would need 200ah of lithium to be 'equal'. I say equal because I have not seen lithium batteries offered at 64ah, so two 100ah batteries would make it easier to compare despite that adding 21ah of capacity. Lithium batteries are also good to 80% DOD, but my math will calculate to 70% to try and be similar to the current AGM setup. So, except for that 21ah, it is even enough to compare. Looking at my math calculations, 200ah of lithium power would equate to 1.65 days of use. A little more than the 1.48 days with the current AGM setup. But, considering both systems are 'allowed' to a SOC of 30% they are pretty close. Two huge benefits of lithium are 1) it recharges quickly and easily, 2) weight - they are significantly lighter. 200ah of lithium can easily be 70% lighter than the same capacity in AGM. So that is a pretty significant factor especially as these rigs get filled with more and more stuff. I currently have about 170 pounds worth of battery between the two under the hood and the additional DC in the bed.
But, the cost goes up
For example, one self heated 200ah lithium I just looked at is $1,900 bucks. And you still need, at the minimum, a DC/DC charger for which RedArc offers a very basic option that can charge at a 20a rate and accept a solar input, which costs $375. This would take 8 hours to recharge at said 20 ah rate. Or with a more robust 50 amp system it would take only 3.2 hours - however, a 50 amp system can easily cost $800 bucks not to mention needing more robust wire than I currently have, and a more advanced system that people gravitate to is about $1,500. So for a good 200ah lithium system you are looking at a minimum of $2,700. And you still need more components - wire, switches, etc. However considering in my specific system it is designed to be 100% modular, I can easily buy just the battery and DC/DC and make it function the same as it is now. So those other component costs are negligible. By comparison, by adding the third battery in the bed, the Genesis system (excluding the same electrical stuff that is needed for the fridge, switch, etc..) came in at about $2,100. The Genesis itself was $1,600, then adding a FR DC series 115ah battery at a little under 500 bucks brings it to just over $2,000.
There is still a problem though
With temperatures. Let me explain. AGM batteries are fine with temps. Of course overheating them is bad like with any, but for cold temps, they have to be literally frozen (which mean they would be close to depleted) or in some crazy -50 degree temp to have issues recharging (according to their electrical engineer). I dont think anybody would be camping then... Anyway, lithium is much more sensitive to temperatures. Really, charging them below 40 degrees is not good. So most of the self heating batteries turn on their heating element at 40, or is it 35... eh anyway those have a cool function. But here is the problem with that. It uses power. Right? So if you calculated your needs and found that you need 200ah of capacity, well you need additional capacity now to factor in the self heating function. So suddenly the $1,900 battery suddenly jumps to probably something like $2,400 bucks. So more cost. More cost to ensure you don't loose ah capacity for your 200ah need. Now we also need to consider when one is not camping. If your truck (like me) is sitting at home for 2 weeks in -25 degree temps in the winter, one of two things happen. 1) you pull the batteries and bring them inside and place on a battery tender, or 2) you plug them into a battery tender when outside - making sure said tender provides enough amperage to not let the batteries drain when their self heating function turns on. Option 1 for me is a no go. For me the whole point is to make a system that does not need constant loading/unloading.. I also do not have a garage. My jeep is already plugged in for a 15a CTEK charger/tender to maintain the start battery, because sitting for 14 days or more/or less at -25 degrees will cause battery charge loss. So now I need two plugs going to the jeep? I'm sure that there is a way to, oh I dont' know, have the DC/DC charger turn on when the tender for the AGM batteries is functional - but now were adding more complications....and more money.
The verdict
It is still out - honestly. Because there are SO many compromises, and one compromise of one system means X is needed or lost, while a compromise of the other system means XX is needed or lost. For example, the charging/tender example just given. I will say I like the current setup of AGM batteries because it (in theory) is enough power to do what I need. But I really DO NOT like the weight. It is an excessive amount of weight, and weight for me is already a major concern - fully loaded I am over axle weights. So going lithium could mean reducing weight easily by 75 pounds, maybe more. But at the cost of $$$$ and more complexity. I like the idea of lithium because of the relative fast recharge rate, and the light weight - but I really don't want to spend $3,000 on a lithium system when I already have spent about 2K on the current.
So what really needs to happen, for me, now, is to test the current system. I need more data points, and I already have the current system installed and working. I need to know how long the fridge will actually last - this coming weekend we supposedly are going to have temps in the high 60's, so I should be able to get a better feel for temps and run time as compared to trying to test when it's only 40 out which is not realistic. I also need to see charge rates. I really don't know what to expect, aside from documented specifications, what amp draw the aux batteries will have when depleted and how fast/slow they will recharge. Will they only draw 50 amps for maybe an hour? Or will they try to draw 200 amps and blow my fuse? (that is an exaduration of course). But that matters, because the 4ga wire that goes to the bed to run my fridge, is the same wire that would recharge the additional battery in the bed, and also the same wire that would be used to run the ARB dual air compressor. So if I start the engine, drive back to the highway, and need to air up while at the same time charging that battery in the bed, I can easily pull 100 amps or more depending on how much power that battery wants to take. I 'think' it will be ok, but only testing and checking temps of the wire with a laser gun will verify. And also, how long will it take to recharge? Will that 115ah battery in the bed recharge to 100% in 4 hours? Or will it require a 16 hour drive, or sitting overnight on the CTEK 15a charger to fully recharge? And how will that recharge rate affect camping? Obviously if it recharges in 4 hours, I can go for a drive and be good for camping for another 24 hours. If it needs 16 hours, then there is going to be a problem as it would mean I realistically only have just over a day's worth of camping before it needs to sit on the charger - because driving 16 hours every 24 hours is not feasible. But again, what is my use case? Which is the most important factor - are these three 5-7 day trips going to happen every year, or just this summer alone? What about the other 1 night camping trips where the current battery amount is sufficient (by calculation).
These are all questions that need answering in order to determine and decide would I do it again. And if anyone has answers to those questions I am all ears.
To sum it up
If you have the money, and don't live where I live and experience sub zero temps for 4 months at a time in winter, then going lithium is clearly the winner - simply due to it's weight, and relatively short recharge time compared to AGM. However, if you live in Montana or somewhere else that gets very cold, don't want to constantly remove the batteries from the truck in winter, or have a heated garage, or don't have the money for lithium and don't care about the weight - then yes I would do the system again.
Looking back - I would try and find a way to charge both AGM and lithium batteries at the same time with one on board charger (like how my CTEK is currently) from one extension cord. If I could find a way to make that work, then I would have deleted the factory aux, put in a full river full throttle group 31 in replacement of the factory MOPAR group 31 under the hood, and found a suitable 200ah lithium/LiFePo4 for the bed to be paired with a 50a DC/DC and upgrade from 4ga wire running to the bed to 2ga wire. The really tough situation for me specifically is the winter temperatures - and not wanting to be unloading batteries all the time.
I certainly hope this helps a few folks understand the pro's and con's of the Genesis and helps them decide which way is best for them. There is no 'best' answer because each option has its own compromises and benefits.
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