Another Lithium battery question

[sgt1577]

New to this and a little confused! I have a 2020 HR Vacationer that currently has four 6V batteries wired to give 12V of coach power. We like dry camping and these batteries don’t last the night in colder weather. My setup looks like this. I want to switch to something like this! Seems like it should be easy enough but I suspect it’s not.

I have the typical Fleetwood setup with the Magnum Energy 2000 inverter. I would appreciate hearing from anyone that has made this conversion!

Thanks!

[twinboat]

So, you want to replace 400 AH of capacity with 225 AH of capacity ?

If you don't adjust your Magnum to lithium charging specs, you will only charge them to about 80%. Alternator charging will do the same.
Now your less then 1/2 of what you had, with good batteries, and your inverter may draw more then the batteries max and shut the battery down.

2 of them would be better.

[dvspl]

Twinboat is on target, but I'm not sure that even 2 of the LIFEPO batteries you showed will help. If your current 400 AH battery bank doesn't last the night, you'll need more than that, regardless of their chemistry. I'd start by figuring out my battery capacity needs. How many AHs do you think you'll need for a worst case scenario?

[Persistent]

I do not own and have not made conversion with your model RV. Still I can offer good advice.

Current Installation
I see the current battery bank is 3 years old and shows excessive dirt and corrosion. It is a short life for deep draw lead acid batteries. Cleaning up the connections and maintaining water levels may improve the battery bank you have. Replacing damaged connectors can help a lot.

You did not report your charging practices. Using good charging and storage practices can greatly improve performance. See attached file if needed.

Storing lead acid batteries not full charged kills a lot of lead acid batteries fast. See attached file if needed.

Switching to lead acid AGM batteries may prevent the build up of dirt and corrosion for the future. Of course water levels need not be monitored for AGM batteries.

Chinese Li Batteries
The new LiFePO4 battery you suggest has some issues. First, the new capacity is probably about half of the old capacity. So, if current capacity is not good. New capacity may be much worse.

Second, buying Chinese batteries from a Chinese company is risky. Redodo Power is apparently a new entity and may or may not be a good one. They do advertise customer support. You might try the support and see if they give reputable advice about your proposed system.

In spite of most Li battery cells being produced in China, the design and assembly is vital to good performance. Many Chinese companies have produced catastrophic results with no customer recourse. Battle Born batteries cost more because the assembly process is more expensive to produce consistent balanced batteries. They also provide extensive advice to prospective customers. They will carefully evaluate your plan and give excellent advice before you buy.

Battery Charger
The Magnum battery charger you have is capable of charging the proposed Li battery.
See user manual.

Remote control
The Magnum charger you have requires a remote control with Li setting to work with Li batteries. What model of remote control do you have?

“Battery Profile Presets: Using the ME-RC, ME-ARC, or ME-MR Remote Controls, easily choose from and set standard battery profiles, including Lithium Iron Phosphate (LFP) – only available via the ME-RC and ME-MR, Gel, Flooded, AGM1, and AGM2.”

Bridge Circuits
I did not find extensive instructions for the Redodo Power battery. Usually there is a caution to not charge Li batteries on the same charging circuit as lead acid batteries. I assume your engine start battery is lead acid. Charging the engine battery from the house side or the Li battery from the engine system can be problematic. Some people succeed. Some do not.

Using the engine system as your primary charging source would work better with a battery to battery charger that has Li settings. This means changes to the Bridge Circuits. Poor performance especially with low quality Li battery designs and builds should be expected.

Starting your engine using the Li to assist is possible. Charging the engine battery using the Magnum set for Li can have voltage profile issues if used regularly or for long periods.

Other equipment
Battery state of charge meters designed for lead acid may not work well with Li. Some SoC meters can be set for Li.

Temperature Issue
Lithium batteries in New York weather can be an issue. Lithium batteries have a low limit for charging. Many can not be charged below freezing.
Lithium batteries have a lower limit for using them (discharging).
I did not find charging and discharging temperatures for the Redodo battery. However, some consideration must be made to deal with low temperatures. Heaters are available that work while charging. I don't think the Redodo has built in heaters.

[wopachop]

Originally Posted by sgt1577

I would appreciate hearing from anyone that has made this conversion!

Im jealous!! Havnt done it yet. Waiting for my 6v batteries to die. I was very disappointed with them out camping. Even brand new i kind of expected more. Your sizing looks good. 230ah is roughly a good equivalent to your current setup if it was healthy and new. If you have the physical room and budget as you go up from around 230ah you will now be increasing your capacity from what it used to be.

Probably a good chance you were not fully charging your 6v's. You kind of have to hit them with a super heavy charge a few times a year. Most people never do it. Usable capacity suffers.

[sgt1577]

Thanks for all the responses! That current mess I have with dirt and corrosion will be my first clean up project. At 3 years old it may be time to replace the batteries that I have and give that a go!

Thanks
Steve

[wopachop]

3 years isnt all that old. Unless when camping you really drain them super low. They could be low on water as well. Giving you not the best results when camping.
Generally speaking i dont think you got your moneys worth yet. Unless again you really use and abuse them. Its what theyre there for is to be used.

Does your charger have a setting for flooded batteries? There is a chance you could get better results from your current batteries. Clean up the terminals. Check water. Then do an equalization charge if possible. Even better you take specific gravity readings but that might be overkill. Since you got 3 years out of them, and looking to move onto new chemisty batteries. If you have lots of camping buddies someone might have an SG meter you could borrow.

[Bsqrd]

I completed my lifepo4 conversion last year. If you do not understand electrical basics and circuits, do not attempt. You will have to modify your BCC, add a DC to DC charger to protect your alternator and a charger for your engine battery when on shore power. Also many other things as mentioned above. After seeing the condition of your battery bay I would say clean up your wire connections and go with agm batteries as suggested.

[Mudfrog]

Originally Posted by wopachop

3 years isnt all that old. Unless when camping you really drain them super low. They could be low on water as well. Giving you not the best results when camping.
Generally speaking i dont think you got your moneys worth yet. Unless again you really use and abuse them. Its what theyre there for is to be used.

Does your charger have a setting for flooded batteries? There is a chance you could get better results from your current batteries. Clean up the terminals. Check water. Then do an equalization charge if possible. Even better you take specific gravity readings but that might be overkill. Since you got 3 years out of them, and looking to move onto new chemisty batteries. If you have lots of camping buddies someone might have an SG meter you could borrow.

Agree.. It does indeed look like the batteries weren't taken car of very well. Cleaning up the mess, checking water level, and making sure the charger is set correctly might get things going better for the OP.

Only getting a day out of four big 6 volts is terrible and indicates to me that either there is no rationing of power or that something is wrong with the system. My two 12 volt lead acid batteries are 8 years old and will probably go longer than that, even in cold weather using the furnace. Of course a difference here is that I don't use a inverter because I know they aren't very efficient!

[creativepart]

I made the switch from 4-100aH AGMs to 2-200aH Renogy LFPs (LFP = Lithium Iron Phosphate) last spring. The switch was well worth it and working great.

However.

The more you research the more issues you will find. Don't let that stop you, but you must address each issue up front. Regardless of what battery manufacturers tell you, these are not simple drop in replacements. If that comment stops you... well, that's good to know.

What are the issues:

1. Lets start with your battery box. It is open to the air because it has to be with Lead Acid batteries. You will need to close that up. You'll find that freezing weather and LFPs don't mix well and open battery boxes become an issue.

2. Sizing issues. You can install 1/2 as much amp hours as Lead Acid batteries when you switch to LFP. But that's just going to be something you regret later. You'll want at least as many amp hours as your old battery bank. So, start with that number.

3. Inverter Charging issues. The Magnum MS2012 can be setup to charge LFP batteries, but the previously mentioned "L" version of the controller is pretty scarce. You can use the ARC and ARC50 remotes to setup charging, but it's not as simple as an ARC-L remote. If you have the ME-RE simple 3-button inverter remote you'll be required to upgrade to at least the ME-ARC remote. The 3-button remote is too basic to set up the proper charging profile.

4. Alternator charging issues. LFP batteries work vastly differently than lead acid batteries. Your alternator is designed to work with LA batteries. The differences can mean problems for your batteries but bigger problems with your alternator. You must research all the implications of this including how your RV connects your house batteries to the alternator when the engine is running. Many remove that connection and prevent the alternator from charging the LFP batteries. Then other charging devices need to be installed to replace that missing charging.

5. Temperatures. LFP batteries can be ruined if charged when the batteries are below freezing. At a minimum you need to insure the batteries you are considering have a built in BMS that automatically cuts off charging as the batteries get closer to freezing. Even with that, batteries with internal heating built in will help with this even more than the low temp cut off. You can get batteries with the low temp cut off and add external heaters as an option, as well. Really inexpensive LFP batteries don't provide low temp cut off BMS features.

6. Battery Monitoring. You'll want some more advanced battery monitoring with your LFP house batteries than your RV has installed right now. Your RV has a voltage based monitor made for lead acid battery voltages. You can add a shunt-based battery monitor and or you can buy batteries with built in bluetooth monitors that let you monitor the true state of charge of your batteries. Really inexpensive LFP batteries don't provide this.

By the way I think LFPs are a great improvement and worth the effort. But if these details give you pause you may consider buying a new set of AGM batteries. You know they will fit. They will be easy to install. They will cost half as much. They will be maintenance free. They're fine with your open battery box and with freezing temps. And, they will work with all your existing monitors, chargers and inverters.

[Captain8]

Everyone on here is right, you'll be swapping 400AH to 225AH so will get half the battery you had before. You need 2 of those to get the same and 4 of them to get double.

To answer your question, its simple, you pull all the batteries out, toss the connector cables between batteries, and plug everything in the positive and negative of the new one. The problem is the inverter needs lithium charging mode and you need to disable the alternator from charging (pull the fuse in BCC)

The main issue is why are you using 400AH of batteries overnight? Buy a smart shunt for $100, wire it up to the neg battery terminal and see how much power you're using. turn everything off and then turn on one by one and write down approx how much power each thing uses.

Sounds like you're using 1500w electric heaters and they'll drain your battery in a few hours.

[theoldwizard]

Originally Posted by creativepart

4. Alternator charging issues. LFP batteries work vastly differently than lead acid batteries. Your alternator is designed to work with LA batteries.

The best solution is buy a quality DC-DC charger. Set the output for LiFePO and life will be good !

[computerguy]

If you do a search on Bounder Lithium solar upgrade in the Fleetwood owners forum you’ll find a post from me that details the installation on a ‘16 Bounder. Should answer 95% of you questions on a similar setup

[wopachop]

Originally Posted by Captain8

Everyone on here is right, you'll be swapping 400AH to 225AH so will get half the battery you had before. You need 2 of those to get the same and 4 of them to get double.

Not everyone. Its kind of weird on this forum. Seems like the same handful of guys will chime in on battery topics. Problem is about half of them still dont understand you cant compare the usable capacity of a flooded 6v battery bank to that of a lithium bank.

I do like the advice one guy above gave. He understands the lithium has about double the usable capacity, but still recommends trying to go big as you can. If you used to have 400ah of flooded batteries, and can afford and fit 400ah of lithium, then that would be a great choice. Now you just about doubled the capacity in roughly the same physical footprint of space.