Lithium Battery Upgrade Question

[jeffem62]

Just got our 2021 Force 34KD with only 3800 miles. Used very little but a bit concerned about the batteries. Original owner replaced the Chassis (Start) batteries with new AGM but the Coach batteries are stock. Looking at replacing the two AGM with One Ionic Lithium 12V 300Ah | LiFePO4 Deep Cycle Battery + Bluetooth + Heater.

For those that have made the change:
Is one 300ah enough? Not big boondockers but I see potential in the future.
Any other pieces and parts i will need?
I’m guessing I’ll need to change some settings?
Can I have AGM chassis and Lipo coach?

Thanks for the help.

Jeff

 

[Judge64]

You first want to determine your power needs i.e. what do you want to run and what are you capable of running? Questions you first need to ask and answer are:

1. What size is your Inverter?

2. What appliances are wired to run from the Inverter (Fridge? A/C? Oven?)

3. Based on what you want / able to run, how much power does each item typically draw?

4. How long do you intend to run each item?

5. Will you be charging laptops, tablets, etc. and how much power will they require?

6. What are your power needs today vs what do you think they will be in the future?


After you answer those questions, you can determine if 300Ah is enough.


I had a Super C and did a Lithium Conversion. I installed a 3000W Inverter / Charger and rewired the coach so I could run any appliance off the Inverter. I wanted to be able to run one of the two A/C's as well as the stove or over..... plus charge devices.... and I already had two fridges running off AC power.

I also wanted to be able to run on batteries for a minimum of 12 - 24 hours when running an A/C. I ended up installing 850Ah of LiFePO4 batteries.


If you don't have an Inverter / Charger installed today, you need to make sure your Converter / Charger can support charging a LiFePO4 battery.

You can have an AGM chassis battery and Lithium house batteries. But ff your coach has a BIM (Battery Isolation Manager) that allows shore power to charge your chassis battery and the alternator to charge the house batteries, you will want to change it to something like an LI-225 BIM.

If you have a solar charge controller, you will want to make sure it allows for setting changes to charge LiFePO4 batteries.


So installing Lithium batteries is doable... but it takes some planning and investigating to do it right.

 

[Aussieguy]

You can have AGM on the start (chassis)

Depending on your alternator’s rating you may have to disconnect the alternator charging or replace it
with a lithium BIM or a bc-dc charger

Boondocking
I use solar to recharge house after each nights usage
Works good for me …. Your results may vary
Depends on if you use a lot of battery capacity on inverter power

Search forum fore lifepo4 or lithium
Tons of info already on the subject

 

[PhilFromMaine]

Just got our 2021 Force 34KD with only 3800 miles. Used very little but a bit concerned about the batteries. Original owner replaced the Chassis (Start) batteries with new AGM but the Coach batteries are stock. Looking at replacing the two AGM with One Ionic Lithium 12V 300Ah | LiFePO4 Deep Cycle Battery + Bluetooth + Heater.

For those that have made the change:
Is one 300ah enough? Not big boondockers but I see potential in the future.
Any other pieces and parts i will need?
I’m guessing I’ll need to change some settings?
Can I have AGM chassis and Lipo coach?

Thanks for the help.

Jeff

I like Judge64's answer and methodology, but not everyone has his temperament and analytical skills.


I would probably start with the 300AH and see how it goes. Unless you are running air conditioning, 300 AH should meet all your needs. If and when you decide to do serious boondocking you can add more storage as needed.

 

[Tony Ramirez]

So installing Lithium batteries is doable... but it takes some planning and investigating to do it right.

It's not just plug & play, just needs to be well thought out. Since yours is a '21, your charger /converter is most likely LiFePO4 compatible. If you have a residential fridge, 300AHs might be iffy in the mornings. My fridge & a few lights use ~175AH before my solar really kicks in. If using the furnace, TV & other stuff, you would be WAY low.

Also, consider some solar, Especially if you want to start boon docking. Combined w Lithiums, it's a game changer.

 

[jeffem62]

Thanks yall so much for the insight / information. Definitely not something I want to rush into. Want to do it right.

I do have two 100 watt solar panels with a 30 AMP controller
1,800W Inverter
Owners Manual says I have 160amp BIM. Have not located that yet.
Residential Fridge

So many different Lipo companies. Do yall have any preference on Brand / Model?

Also looking at: Epoch 12.8v 300Ah. Price for one battery is $999 about half the price of the Ionic.

 

[Tony Ramirez]

I went w 2 of the Epoch Essentials 460A batts, $1300each. The 2 fit in just a hair bigger footprint than 4 6v Golf Cart batts.

I couldn't be happier with them so far.

 

[Tucson Steve]

I'm not trying to throw cold water on your idea, but are you having problems with the AGM batteries? It's easy to get caught up in the "everyone says lithium is better, so I need to do it" thought process.

My suggestion would be to use it as is for a while until you better understand your needs. You have enough other systems to learn before you start worrying about upgrades. Unless your AGMs are dead, just wait a while. Lithium prices are not going to go up, and will probably go down. Stop spending money, and enjoy what you have for a while.

Love, Dad.
(After I said it, it sounded like really fatherly advice.)

 

[jeffem62]

Tucson Steve - Thanks for the advice!! I totally agree with you do not like spending money just to spend. Main reason I was thinking about upgrading the Coach batts is because the Chassis Batteries were both bad when I purchased it earlier this month. Thinking of getting ahead of the inevitable. Right now the batts seem to working ok but we have not really put any stress test on them. Ironically our first trip is to Tucson on October 10 as kind of short test. Are you in Tucson?

 

[Tucson Steve]

Yes, originally from Tucson, lived 34 years in Seattle area, but back home again when I retired.

 

[Aussieguy]

Starting and coach batteries are different as chalk and cheese
If one dies that is no reason to think the other may do so soon

 

[tewasch]

I can appreciate your position. I bought a used 2021 I3 in January and, on our first trip out, watched with nervousness as my battery level dwindled in one night. You've gotten some great advice here from everyone. Having done what you're thinking about doing, I can share my recent experience.

The EPOCH 300 AH package is a bit tall. Make sure it will fit in the space you're interested in. They work well. BT app is just fine.

1800W inverter is a bit small. I have 2000W (not much bigger), but I can run EITHER the AC or the microwave. I had to add a "soft-start" to the AC unit to get it to work.

Propane/electric fridge is an electricity hog. 450watts for 24 hours at 13.4V is something like 805 AHr--so that's out of the question.

Solar charging + Alternator charging is a very nice option for filling your battery. I have 800W each. I almost-never plug-in anywhere and I hate the noise of a generator.

I use a DC-DC converter rather than a Li-BIM. I have a larger 640 AHr battery and worry about the instantaneous currents when I have a deeply-discharged house battery. Victron recently came out with a 50A version in a small package that is very, very efficient and runs cool.

Yes, your charger probably has a small switch on it to switch it to Lithium charge profile--mine did.

I end-up using more propane for my fridge than I wish I had to--but my 640 AHr isn't quite big enough. If I switched to a residential compressor fridge, I'd be good. When it comes time to replace the fridge, I'll probably do that. I monitor my power levels and flip to electric often when sun and plans call for it.

One other thing I liked was that I used the BougeRV solar panels that I can walk on. They stick down on the roof--no holes. First time I every bought a solar panel and got MORE power out of it than they advertised.

Finally, my wife noticed my anxiety that first night we were out and I was watching the number of lights/fans that were on, etc. (we were at a Harvest Host that did not allow generators). If you have to replace batteries, I'd make the jump. You'll really appreciate never thinking about it again. Tom.

 

[PhilFromMaine]

I'm not trying to throw cold water on your idea, but are you having problems with the AGM batteries? It's easy to get caught up in the "everyone says lithium is better, so I need to do it" thought process.

My suggestion would be to use it as is for a while until you better understand your needs. You have enough other systems to learn before you start worrying about upgrades. Unless your AGMs are dead, just wait a while. Lithium prices are not going to go up, and will probably go down. Stop spending money, and enjoy what you have for a while.

Love, Dad.
(After I said it, it sounded like really fatherly advice.)

Good advice Steve. My only issue is that prices may go up depending on whom becomes POTUS. One candidate is promising heavy tariffs on Chinese goods imported into the USA.

 

[TitanMike]

Good advice Steve. My only issue is that prices may go up depending on whom becomes POTUS. One candidate is promising heavy tariffs on Chinese goods imported into the USA.

You might be surprised how many lfp battery cells come from Malaysia, Singapore, South Korea, and other countries.

One company already has two plants under construction in AZ to manufacture both Cylindrical and Pouch cells that won't be affected by any tariffs.

 

[DW_DX3]

Our 32KD came with two 300AH lithium batteries. I redid the battery bay to add two more for a total of 1200AH, plus another Magnum 3000W inverter to be used when not on shore power.

This allows me to use the batteries when traveling or boondocking instead of the generator. Running the typical appliances, which includes the standard 120VAC fridge, electric element on the Aqua-Hot and one of the air conditioners, I get 10-13 hours on the batteries in hot Texas weather without worrying about controlling usage. My overall goal was to not have worry about what my wife has turned on, or tell her to turn stuff off. I didn't want to have to tell her she can't have coffee right now for a variety of reasons. Telling that to a Puerto Rican wife will not end well.

We do have the "Explorer" upgrade with the additional solar panels, but I do not factor them in. At best, I get ~800W for a very short time midday during the summer, and quickly downhill from there any other time of day/year.

 

[mookieblaylock]

Quick question - I understand the use of a DC-DC charger to charge the lithiums when driving while protecting the alternator, but what about the other way around? When on generator or shore power, how are folks charging the chassis batteries without a BIM?

 

[DW_DX3]

Quick question - I understand the use of a DC-DC charger to charge the lithiums when driving while protecting the alternator, but what about the other way around? When on generator or shore power, how are folks charging the chassis batteries without a BIM?

The Magnum Inverter charges the batteries. It includes a battery type option for basic Lithium charging or you can set custom battery option to march your lithium battery specs.

 

[tewasch]

We're in a mild climate, so we use the RV all year long. Like my car, this amount of driving keeps the chassis battery up.

I found the Li-BIM documentation helpful....

https://battlebornbatteries.com/wp-content/uploads/2019/01/BIM-LI225-Quick-Guide.pdf

It says that if the chassis battery is below 12.5V and the house battery is above 13.4V, it will connect the two batteries together for an hour. After that, it waits a little bit and then checks again and repeats if necessary. I expect they ran the numbers to make sure this should keep the chassis battery topped-off without too much danger of charging it to 14.5V. I suppose I might be concerned a bit about how this will behave when the chassis battery is near end-of-life. One hour at 225A is a good amount of energy.

Without the Li-BIM, if I were storing the RV for a long period of time and couldn't go start it up every few weeks, I'd probably attach a little 2A trickle charger to the chassis battery.

If it was stored a long time in a lot with no access to AC power, I suppose I'd need to either get a little 12V solar panel battery charger or get a diode or two to keep the chassis battery up to some nominal offset from the solar-charged house battery. Tom.

 

[mookieblaylock]

Thanks, this is what I was trying to get my head around. Would it be overkill to put a separate low amp dc-dc charger in place going towards the chassis batteries? Basically just trying to replicate the entire existing BIRD/BIM setup and maintain the process?

 

[tewasch]

You sure could, but the standby current for the converter might be too much to want to manage. It depends on if you're in storage with no supply to either battery (and you want to make it for months) or if you already have some charging going on for your Lithium battery. If you have any supply to your Lithium, then I think I'd link this to the chassis too.

As the Lithium is always higher than the Lead Acid, I don't think I'd go to the trouble (and standby current needs) of a DC-DC converter. This is always a step-down and only by a small amount (maybe 2-ish volts). I think I'd use a couple 1V drop diodes with a current limiting resistor in series to just keep the chassis at or around 12V. You want to make sure it stops trickling current into the Chassis battery when its 12.5V or so. Tom.