Replacing Lead Acid in RV with Lithium

[Geezershot]

I have a 2003 Motorhome (12V 30Amp). I replaced the two lead acid batteries with two Lion lithium batteries, and a Victron shunt. I'll get the terminology wrong (you are allowed to laugh), but my all-in-one "inverter/charger" doesn't have a "profile" for lithium batteries. What do I need to purchase next? I called the manufacturer of my existing "inverter/charger" and was told to get one that has a lithium "profile" is about $1,600.00+. That's not in my budget.

My immediate need is to fully utilize the batteries, but at some point in the future I would like to add some solar panels. I would like to do a little at a time, without shooting myself in the foot by purchasing a mismatch of parts if I am better off purchasing one component that provides multiple functions.

OK, time to laugh again...

I could go to the auto parts store and purchase a charger that supports lithium batteries ($35 - $100) and plug that into a 110 outlet in my RV and have shore power charge the batteries to 100%, but geez that seems really dumb/hacky. Is there something I can put between my existing inverter/charger that could charge these batteries to 100% without having to replace the entire all-in-one device? If so, where to I wire this into the existing system? What is the name of this device?

Generator Shore Power Alternator
| | |
+---------------+--------------+
|
Inverter / charger
|
Remote monitor <-- new charger <-- Solar
|
Shunt
|
Batteries

If such a device exists? What is it called and what does it cost?

 

[sunshine_eggo]

What converter do you have? Please provide a link, so I don't have to find it myself. Need to know the bulk, absorption and float values.

In most cases, the only time you need a Li converter is for generator charging. Several hours on shore power will fully charge (95%+) most LFP batteries

 

[chrisski]

Can you disable the charge port and hook a charge up to the AC? My converter plug into a 15/20amp plug located on the back of my power distribution panels wit the circuit breakers.

Battery Chargers

If you wish to charge your battery bank with shore power (the grid), you will need a dedicated battery charger. Some RV's and conversion vans will have this built into the converter box. If you do...

www.mobile-solarpower.com

I have the one Will recommends. $260 to $330 the Aims 12 volt 75 amp / 24 volt 37.5 amp dual votlage self sensing charger. For lithium I set the dip ditches to charge at a gel profile, which is th slowest charge and float. I turn it on and off as needed with the converter AC circuit breaker .

There’s other cheaper converters, but this had the closest to the lithium profile i wanted.

I assume you want to keep the inverter, but have a way to charge off the generator. There’s other ways to wire this also.

 

[HRTKD]

The inverter/charger is a package deal. You get all of it or none of it, depending on how sophisticated it is. If it is as old as you say then it probably isn't programmable and you can't disable the charge part of it while connected to shore power. If you disable the entire inverter/charger then you may not get any 120 volt AC into the RV.

As requested above, we need to know more. The charger part may not have multiple stages beyond bulk and float, which would be in your favor. Some chargers include an equalization stage which uses a voltage beyond what LiFePO4 wants to see.

 

[time2roll]

Many inverter-chargers have programmable settings. Or some other setting might be fine such as GEL.
Post the make and model of the inverter you have for best answers. I doubt the inverter needs replaced.