Genesis batteries - lets do some math

[Dan Grec]

@Dan Grec thanks for all the great insight! One question that you might be able to explain to me is what the heck the Egon DC hub does? Is it similar to the Renogy unit? I can't figure out why it is so expensive or why I need it.

https://www.egon.com.au/dc-hub-instal/

You're very welcome.
I looked at the wiring diagrams and stuff for a while, and I thought it was like hte Renogy (DC/DC charger AND solar in one PLUS a big fuse block) ... but then it talks about how you have to connect a DC/DC charger into it.

So I *think* it's just a big fuse block. A damn expensive fuse block.

Anyway, like so many things on the market that are expensive, I see no reason you need it.

I got one of these to wire all my different circuits into the positive of the house battery in my Australia Gladiator https://www.amazon.com/6-Way-Fuse-Block-Negative-Bus/dp/B07DYT2TVS
For $13 it worked great.

Also note the Redarc DC/DC Charger with solar is 4-5 times the price of the Renogy that does exactly the same thing.

-Dan

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[chorky]

You're forgetting that the fridge has a thermostat, and will only actually be "on" for a fraction of that 10 hours in camp. If you've been driving all day and the fridge is full and it's not too hot outside, you might find the compressor only comes "on" for 30 minutes for that entire 10 hours, so you're actually only using 30 minutes of battery time, not the whole 10 hours.

In my Africa Jeep I slept upstairs in my JKU, directly above my Dometic fridge. I could hear it turn on and off (it became a nice reassuring noise). Even on the hottest of hot nights (staying above 80 or 85F all night) it would only be on for maybe 20-30 minutes every hour.



On a "regular" temperature night (maybe 50-60F overnight) it would be on for 10-20 minutes every few hours.

-Dan

You have a few good points. But you are overlooking several things here that I already covered. I do not want two separate systems of different battery chemistries. That excludes lithium right off the bat. I also dont want a DC/DC style system - at least not right now. Because it permanently isolates the two batteries from each other. It also does not allow you to link the two batteries together in order to take advantage of the aux battery for a self jump situation or winch pull with a dead engine - things I have seen before.

I am in no way arguing that this system is ‘better’ than a lithium system. I think most people know lithium provides more ah, is lighter, and recharges a lot faster. But for my use and how often or not often I will use it, lithium is not the best option.

Temperatures are also a huge deal. You operate in Australia. Here in the US lithium is no where near as common yet. Plenty of folks have them but its still relatively new. And it sounds like your doing extended trips practically living out of your jeep. Winter temps for me are easily in the -26 C (-15F) range. And I have not seen temps above freezing for over a month now. on top of that, my, Jeep has been sitting for the last 2.5 weeks. Even with self heating systems, those conditions will destroy a lithium battery. And I dont want to have to worry about bringing it inside due to cold and then remembering to put it back outside and hooking it up.

I think a few folks here are thinking that I am trying to argue that the genesis system and AGM batteries are ‘better’ than lithium and that is not the case at all. However for my specific use case, I do believe that lithium is not the optimum option.

As for the fridge. I dont think you are correct. If you go back and look at the graphs I posted it is clear from their own chart which is based on a real world test of optimum voltage and no items inside the fridge, they show that at 95 Fambient temp with a freezer set to 23 F the run time of the compressor is 73% pulling 1.75 amps per hour. so we discussed for an average ambient temp of approx 70 degrees with a internal fridge temp set to 36 degrees, the fridge will have a duty cycle of about 50%. I called Engle directly and discussed with them. They agreed. But run time here wil also be better with lithium as it holds a higher voltage longer. The calculations in my spreadsheet account for this duty cycle and do not assume the fridge is running constantly, nor only 30 munutes for a 10 hour night. I think making calculations like this is very important to ensure this expensive equipment we all are buying works properly.

So people can do what they will with their individual use cases. Alls I am here for is to provide the information I have found, tested, and verified by talking with various makers of these products, and making calculations for my particular use, in different environments than Arizona or Africa. Those doing a youtube lifestyle living full time out of your rig traveling to warmer areas and not leaving their vehicle in sub zero temps for weeks at a time would absolutely benefit from lithium. 95% of the people on these forums are not like that. So those systems really are not always the best.

I am surprised to hear lithium is so cheap. Are you talking prices from your area in Australia? Or did you look up prices here in the US?

 

[Cape taco12]

Now obviously super expensive, but are there any decent fuel cell generators that would work? You might need to worry less about battery choice, temps and charging abilities.

Iv noticed a few distance race boats in my area converted to Efoy fuel cell generators because they weigh very little and charge at night and during awful weather conditions to keep instruments running 24/7. Offsets their weight in diesel fuel and Lighter than a solar setup with extra batteries, but you need to refill the fuel pod every couple months depending on use.

 

[ToJTornottoJT]

@chorky what you are saying is incorrect though, at least in a sense... first, you don't have to use lithium.. run whatever battery you want, they are isolated systems through the dc-dc controller. You can mix batteries because they are isolated through the charger/controller. You can run the same batteries, different ones, whatever you want. You can charge the second battery with the preexisting system.

The Renogy website is in US Dollars.

If you have to jumpstart the truck just use a portable jumper pack or build a simple capacitor system.

Either way, you can run your fridge for a very long time using a Renogy DC to DC controller/charger and Lithium battery or multiple batteries of another kind.

A better solution for your problem might be a Harvest Right freeze dryer and to leave the fridge at home. https://harvestright.com/home-freeze-dryers/

 

[chorky]

@chorky what you are saying is incorrect though, at least in a sense... first, you don't have to use lithium.. run whatever battery you want, they are isolated systems through the dc-dc controller. You can mix batteries because they are isolated through the charger/controller. You can run the same batteries, different ones, whatever you want. You can charge the second battery with the preexisting system.

The Renogy website is in US Dollars.

If you have to jumpstart the truck just use a portable jumper pack or build a simple capacitor system.

Either way, you can run your fridge for a very long time using a Renogy DC to DC controller/charger and Lithium battery or multiple batteries of another kind.

A better solution for your problem might be a Harvest Right freeze dryer and to leave the fridge at home. https://harvestright.com/home-freeze-dryers/

I do not want two separate systems. I want the ability to fully link them together at will. A DC/DC charger separates them into two separate systems and does not allow them to be linked together. You would have to get another set of cables and a solenoid for that. For which the Genesis system already is.

There is still the issue of 8 months of freezing temps where I live when I probably wont go camping at all unless its to a more southern area - so really it rules out lithium options. The fact is I dont go camping enough to justify a lithium system. If I did or was doing long term travel man I would be building a 150ah lithium setup with an alu-cab hands down. And later on I still can. The Genesis system doesnt exclude the possibility of adding a DC/DC with lithium later on. Or even a DC/DC with another AGM like you mentioned.

That freeze dryer is pretty cool. We actually had a convo about them at work a few weeks ago. Thinking of good ways to store some of our game meats and pre-made meals. Im surprised theyre that cheap I figured they would be quite a lot more.


I am confident that the calculations I have are valid and will work. There are certainly some negatives and I do realize that some un-equal charging will occur. But I dont think it will be as temperamental or as restrictive as a lithium system. And I could always get a solar panel or two (or lithium) if longer term trips become a reality in the future. Theres even a few with built in charge controllers and can hook right up to a port (or using alligator clips if desired).

I think there is still value in the ‘old school’ style of systems for some situations. Dual batteries and a simple solenoid worked for a lot of people for many years. It should still be able to work today as well.

Now obviously super expensive, but are there any decent fuel cell generators that would work? You might need to worry less about battery choice, temps and charging abilities.

Iv noticed a few distance race boats in my area converted to Efoy fuel cell generators because they weigh very little and charge at night and during awful weather conditions to keep instruments running 24/7. Offsets their weight in diesel fuel and Lighter than a solar setup with extra batteries, but you need to refill the fuel pod every couple months depending on use.

what exactly is this? Is it basically just a generator? Havent heard if them before.

I live in a very rural area. Gasoline and diesel and propane is all that is easily accessible. And as of late diesel is restricted to commercial use only - at least at my local pump. Its kinda strange…..

 

[chorky]

For anyone curious of the spec of the battery combiner, here ya go. I was curious about this myself. For those doing extensive and consistent winch pulls it might provide another option. im sure this part can be sourced independently somewhere

 

[Cape taco12]

I do not want two separate systems. I want the ability to fully link them together at will. A DC/DC charger separates them into two separate systems and does not allow them to be linked together. You would have to get another set of cables and a solenoid for that. For which the Genesis system already is.

There is still the issue of 8 months of freezing temps where I live when I probably wont go camping at all unless its to a more southern area - so really it rules out lithium options. The fact is I dont go camping enough to justify a lithium system. If I did or was doing long term travel man I would be building a 150ah lithium setup with an alu-cab hands down. And later on I still can. The Genesis system doesnt exclude the possibility of adding a DC/DC with lithium later on. Or even a DC/DC with another AGM like you mentioned.

That freeze dryer is pretty cool. We actually had a convo about them at work a few weeks ago. Thinking of good ways to store some of our game meats and pre-made meals. Im surprised theyre that cheap I figured they would be quite a lot more.


I am confident that the calculations I have are valid and will work. There are certainly some negatives and I do realize that some un-equal charging will occur. But I dont think it will be as temperamental or as restrictive as a lithium system. And I could always get a solar panel or two (or lithium) if longer term trips become a reality in the future. Theres even a few with built in charge controllers and can hook right up to a port (or using alligator clips if desired).

I think there is still value in the ‘old school’ style of systems for some situations. Dual batteries and a simple solenoid worked for a lot of people for many years. It should still be able to work today as well.




what exactly is this? Is it basically just a generator? Havent heard if them before.

I live in a very rural area. Gasoline and diesel and propane is all that is easily accessible. And as of late diesel is restricted to commercial use only - at least at my local pump. Its kinda strange…..

It’s an automatic generator of sorts very quiet limited exhaust. Designed for RVs, Boats and remote sensor/data collection that can’t afford to rely on solar. I don’t know if anyone makes one smaller than EFOY yet. You would need to order the fuel pods I believe but they last along time of constant use. The also sell different sizes.


https://www.my-efoy.com/en/efoy-fuell-cells/how-it-works/

 

[chorky]

Thats pretty neat. I wonder how common they are

 

[chorky]

So as the fridge arrived today I have turned it on just to make sure all works ok. Its nice and quiet compared to the snomaster.

with it on the coldest setting (0 deg F in freezer and 30 F in the fridge compartment), it is running approximately 75%. This is running on AC in the house with inside ambient temp at 71 currently.

No doubt it will run more often when full and less often when I lower the temp so that the fridge is hovering around 35 F

Just to show that duty cycles are usually longer than anticipated.

it is interesting to note that the duty cycles are pretty consistent. this is also after the fridge being on for 2 hours to equalize

so this calculates to 26.1 amps used in 24 hours. If you recall in post 14 that at 70% soc the genesis aux battery has 23.04 amps available. So this fridge, at the current temps, would run for just shy of one full day with the engine off and no additional loads or charging.

 

[mrmo]

I've always heard 50% discharge for AGM batteries. Even then, you're looking at tops of 40ah or so. This is pretty much why I think dual (under hood) battery setups are a thing of the past.

What you'll see going forward is a starter battery under the hood paired with a lifepo4 "house" battery in the cab. I built my lifepo4 battery from Chinese cells. 304AH for about $900. It weighs 47 lbs. An equivalent AGM would be like 450 lbs, nearly 10 times heavier.

Go a bit further out and you'll stary to see lithium titanite replace lead starter batteries. This will be great!

Im looking at Dakota LifePO4 batts...I would like to use two small ones to get 100ah, but Im not sure about charging them. I says it comes w a charger, will my alternator charge this type of batt? I want to use it for a second batt in a deep cycle mode for an invertor, winch, compressor, etc.

 

[ajkaz]

In my JK prior to the Genesis kit I could run my FULL Whynter 65 qt fridge for 2.5 days and still start the Jeep. This was using the largest size Yellow Top I could fit in the stock JK tray. I would precool the fridge with everything in it at home on 110v. Once I got to Rubicon Springs the Jeep didnt start for about 60 hours. Then it would fire right up with little trouble to leave. Did this several years in a row... Once I added the Genesis kit I never even tracked battery life as I had no issues at all.

FWIW in my gladiator I wouldnt even consider the Genesis kit, I intend to swap in a Lithium battery once the OEM dies. I do now use a 568WH portable battery pack, with a 100 Watt solar panel. I can go about 5 days charging 18650s for flashlights, phones, GPS and running the fridge before it dies. This is Moab in September, moderate temps and long charging days.

 

[chorky]

Im looking at Dakota LifePO4 batts...I would like to use two small ones to get 100ah, but Im not sure about charging them. I says it comes w a charger, will my alternator charge this type of batt? I want to use it for a second batt in a deep cycle mode for an invertor, winch, compressor, etc.

you really do not want to be connecting a lithium bsttery to the rest of the vehicle system directly. It is a different chemistry type that requires different charging methods. Lithium systems really should be a separate system not connected to your main vehicle system. Using a DC/DC charger to charge the lithium battery from the main vehicle battery/alternator is the best method. adding solar in top of that helps with extended stays. A DC/DC charger essentially separates them into two systems.

Powering a winch from a lithium battery is a no no. that is too much amperage draw too fast and theyre really not made for that.

Powering a compressor might be ok for limited run times depending in the amp draw I suppose. But you want to be careful with how it is set up. If you wire it only to the lithium battery then only that battery will power it. If you want the option to power the compressor via lithium or your alternator then you would need to hook it up twice with two different switches, diodes to prevent feedback voltage, and probably some relays as well.

 

[ajkaz]

So as the fridge arrived today I have turned it on just to make sure all works ok. Its nice and quiet compared to the snomaster.

with it on the coldest setting (0 deg F in freezer and 30 F in the fridge compartment), it is running approximately 75%. This is running on AC in the house with inside ambient temp at 71 currently.

No doubt it will run more often when full and less often when I lower the temp so that the fridge is hovering around 35 F

Just to show that duty cycles are usually longer than anticipated.

it is interesting to note that the duty cycles are pretty consistent. this is also after the fridge being on for 2 hours to equalize


so this calculates to 26.1 amps used in 24 hours. If you recall in post 14 that at 70% soc the genesis aux battery has 23.04 amps available. So this fridge, at the current temps, would run for just shy of one full day with the engine off and no additional loads or charging.

It will run substantially less often when full and will run shorter times as well. Give it a shot with as many gallon jugs of water as you can fit. My fridge runs a ton when empty or close to empty.

 

[chorky]

In my JK prior to the Genesis kit I could run my FULL Whynter 65 qt fridge for 2.5 days and still start the Jeep. This was using the largest size Yellow Top I could fit in the stock JK tray. I would precool the fridge with everything in it at home on 110v. Once I got to Rubicon Springs the Jeep didnt start for about 60 hours. Then it would fire right up with little trouble to leave. Did this several years in a row... Once I added the Genesis kit I never even tracked battery life as I had no issues at all.

FWIW in my gladiator I wouldnt even consider the Genesis kit, I intend to swap in a Lithium battery once the OEM dies. I do now use a 568WH portable battery pack, with a 100 Watt solar panel. I can go about 5 days charging 18650s for flashlights, phones, GPS and running the fridge before it dies. This is Moab in September, moderate temps and long charging days.

sure you ran for 2.5 days but you have no clue where the battery SOC is. Thats a toss up and risking a bad situation. I prefer to be more accurate.
also, simply putting a lithium battery in replacement of the factory AGM battery is NOT a good idea and can cause major issues possibly a fire. @ShadowsPapa covered that before in another thread somewhere


The portable packs are a great idea. I just didnt want to have another thing to unload and reload vor a one night weekend trip. But it is the simplest option especially with the ability to charge while driving from the 110 outlet

It will run substantially less often when full and will run shorter times as well. Give it a shot with as many gallon jugs of water as you can fit. My fridge runs a ton when empty or close to empty.

I am going to do that test this weekend and check duty cycles and temps with the fridge and freezer full.

 

[ajkaz]

sure you ran for 2.5 days but you have no clue where the battery SOC is. Thats a toss up and risking a bad situation. I prefer to be more accurate.
also, simply putting a lithium battery in replacement of the factory AGM battery is NOT a good idea and can cause major issues possibly a fire. @ShadowsPapa covered that before in another thread somewhere


The portable packs are a great idea. I just didnt want to have another thing to unload and reload vor a one night weekend trip. But it is the simplest option especially with the ability to charge while driving from the 110 outlet



I am going to do that test this weekend and check duty cycles and temps with the fridge and freezer full.

I spoke with the Rep for Antigravity Batteries, they are plug and play. They have protections already built in which are designed specifically to allow OEM electrical systems charge their batteries. I have no need for a winch, ran my last Warn Zeon for 4 years and never used it, not even once... I am not adding one to my current build. Either Ill figure a way through or someone else in the group will have a winch.

Though I did not know the exact SOC of the battery during my trips, I do know it never dropped below 10V as I have a voltage readout installed where I ran the fridge connector in the rear.

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