question on lithium battery charging

[davidreidok]

I have a 2012 little guy wide

currently have a standard lead acid battery

want to install a lithium battery

The little guy has a OEM built in electrical system that charges the lead acid battery when hooked to shore power or when towing.

Do I need to add some sort of additional charger for the lithium ? if yes any suggestions on what to buy ?

much appreciated

[TimC]

I'm assuming no solar charging now or in the future, so, the NOCO brand "Genius" chargers are good options. They make a variety of amperages. Be sure to look for a 12V (nominal) charger that is LiFePo4 compatible. I have a 7.2amp model that works great for charging my LiFePo4 batteries. My son has a 5amp NOCO model to supplement his solar charging. There are trickle chargers all the way up to 10amp.

A good 10a charger is about $100...
https://www.walmart.com/ip/NOCO-GENIUS10-6V-12V-10A-Smart-Battery-Charger-and-Maintainer/542154058?wmlspartner=wlpa&selectedSellerId=0&wl13=2434&adid=22222222277542154058_117755028669_12420145346&wmlspartner=wmtlabs&wl0=&wl1=g&wl2=c&wl3=501107745824&wl4=pla-294505072980&wl5=9019075&wl6=&wl7=&wl8=&wl9=pla&wl10=8175035&wl11=local&wl12=542154058&wl13=2434&veh=sem_LIA&gclid=CjwKCAjw1YCkBhAOEiwA5aN4ASlb9cp71m_SNWf-vkyF6bBnLptgn-guAV-SBuUhx-pfsK26S8JkExoCUJkQAvD_BwE&gclsrc=aw.ds

[Capebuild]

It's been a while since I did the research for my trailer's build and its electrical system..... but I do remember there can be an issue with charging a lithium battery via your car. It can put a strain on your tow vehicle's alternator. I have a Battleborn lithium battery and use a Victron charger for shore power charging. I do not charge the battery off my tow vehicle. I do have 2/ 100 watt solar panels. Between the solar panels and the shore power charging that seems to keep the battery fully charged. If you do a bit of research there are chargers that can charge lithium batteries off your tow vehicle without damaging the alternator.

John

[Pmullen503]

There are lithium batteries with a built in BMS that allows charging with a simple dc voltage. Be sure to match the charger to the battery.

If you want to build your own and save alot of cash: batteryhookup.com. If you use 38120 cells you can build a pack with no welding.

Building lithium batteries is not a job for the careless....

[davidreidok]

I sent a request to nucamp (this company actually built little guy teardrops) and their advice was to take the teardrop to a local dealer as they thought the OEM charge controller (what ever that is) would need to be changed. This answer surprised me as far as they built the trailer but did not know the answer.

I hope there is a little guy owner out there who has made this conversion and knows the answer.

appreciate the feedback.

[TimC]

Can you post a photo or two of your existing battery and charge controller? Model numbers would help. That info might help diagnose what you have and what you need to replace it with.

This isn't rocket science. Taking simple precautions will allow anyone to make the DIY upgrade you need.

Tim

[davidreidok]

The charger is the OEM built in electrical system that came from the factory on my 2012 little guy 5 wide teardrop rv. This OEM system automatically senses when I connect shore power and the interior plug ins work for 110 volt AC gadgets. Normally it switches to 12 volt and the interior plug ins for cigar lighter and USB devices work. The battery now in is a standard lead acid RV style from WallMart. I think the existing lead acid battery will trickle charge from both shore power and when hooked to my 12 volt Tow Vehicle

Thinking more about it I think what I need to find is a Lithium battery that is not going to be damaged by the OEM system and my tow vehicle system when it attempts to charge the new lithium battery. The OEM system works great for lead acid standard batteries.

Appreciate the help.

[Pmullen503]

Sound like the OEM charger is handling a lot of switching duties. If it's still working, why not just stick with it and get a good lead acid battery or add a second battery if you need more capacity?

[TimC]

... This OEM system automatically senses when I connect shore power and the interior plug ins work for 110 volt AC gadgets. Normally it switches to 12 volt and the interior plug ins for cigar lighter and USB devices work. ...

Appreciate the help.

My opinion may not be relevant here as I build completely off grid teardrops. I don't use 110v power at all and don't plug into shore power ever. I also don't charge from a tow vehicle.

That said, I agree with Pat. You have an 11 year old RV Charge Controller/Inverter electrical system that was not designed for LFP batteries and may not work. Or, I should say, it will work but will likely shorten your LFP life and limit its potential. New Progressive Dynamics charge controller/inverters are made for LFP. You could upgrade to one of those for a few hundred dollars and some labor cost. Your existing charging system may not charge the LFP to its potential (>14volt). If weight isn't an issue the AGM will work fine. It'll be a bit cheaper but last half as long as a LFP battery. And you won't need to change anything else.

Tim

https://www.etrailer.com/RV-Converters/Progressive-Dynamics/PD4060K.html?feed=npn&utm_source=google&utm_medium=cpc&utm_campaign=Google%20%7C%20Shop%20-%20RV%20Converters&adgroupid=94826433060&campaignid=1732237894&creative=416907787363&device=c&devicemodel=&feeditemid=&keyword=&loc_interest_ms=&loc_physical_ms=9019075&matchtype=&network=g&placement=&position=&gclid=CjwKCAjw-IWkBhBTEiwA2exyO9ow9l7URuqiEqWLJUrpu6cNI5M6DOVKJel8VpOlCSmKYPeWCXyRExoCdAwQAvD_BwE

[bdosborn]

Can you post a photo or two of your existing battery and charge controller? Model numbers would help. That info might help diagnose what you have and what you need to replace it with.

Ditto that. Why try and solve this problem with one hand tied behind you back? Post some photos....
Bruce

[davidreidok]

appreciate all the input.

Please consider this question as closed.

David

[Numlyme]

Since lithium batteries have different charging requirements compared to lead acid, you'll likely need a specific lithium battery charger. Most OEM systems are designed for lead acid, so adding a charger for lithium is a smart move.
I've heard good things about IoT Battery for RV setups—they offer reliable chargers that are compatible with lithium batteries. Checking out their options might give you a good starting point. I think it's important to match the charger to your battery's specifications for safe and efficient charging.