All things Lithium

[Kemp B McLeod]

Good Day,
We have our coach at a property that we visit annually. It has 50 amp. power connected. I have 6 - 6v batterries that are aging out. I want to replace them with lithium. Is there a formula or rule of thumb for the minimun Ah I need to operate just the 12v load? My plan is to install one unit to satisfy that requirement  and then before we get back on the road to add more. Thanks in advance for any pointers.
Cheers,
Bruce

[Carl Boger]

you currently have a little over 320 amp hours of useable battery storage.  If you don't use the RV when not plugged into shore power than a 200 amp lithium battery should be plenty.  If you want to keep the capacity you currently have look for a 300 to 350 amp hour lithium battery.  if you want more get one or 2 460 amp hour batteries.

I am using a Vatrer 460 ah battery in the space that my 4-6 volt batteries were.  There is still room to spare.

I copied the AZ Expert video using the same battery and BIM to make the switch.  I set the inverter to a gel setting to charge the battery 

[Kemp B McLeod]

I've enjoyed his videos as well. So, what say you all. I have the stock Xantrex inverter/charger. If it will not reach the 100% 14.6 v, can occasionally top it off in place with a charger designed for lithium to equalize the cells?  Or will it try to charge my chasis batteries unless i disconnect them?This is not my long term plan. It's parked and plugged in for our winter destination.  Next season I am upgrading the  inverter.
Thanks again for any knowledge sharing

[Carl Boger]

I originally had a Freedom 15 xantrex inverter, a real primitive inverter.  On the gel setting it kept the Lithium battery charged to 99% at all times.  If I hooked up a lithium specific trickle charger I could get it to 100%. That worked fine for me for over a year until the inverting part of the inverter died.  I didn't want to spend a fortune so I bought a older Xantrex 2000 XC and installed it.  I also bought a new remote for it. The inverter did not have a lithium setting, but the remote did.  Turns out that won't work.  I then set them both to a user mode and set in the battery charging profile parameters.  Works as advertised, but guess what still maintained 99%SOC just like the old gel setting.

Then I replaced my old solar panels with 2 - 100 watt panels and a victron 100/20 controller set to lithium.  It also charges the Battery to 99% SOC.   

All of that being said I suspect there is a setting on you inverter that will work the the lithium BIM to keep the battery properly charged.  Try it before spending more money unless you just need a bigger inverter.