Lithium Batteries

$900 for a battery is an outrageous cost if you are not camping off the grid. Then add another $200 for a converter then who knows how much for an install.

mikewats wrote:
Need a new battery. I was thinking of a 12V Lithium battery. Not very familiar with them, will my AC/DC inverter 50amp with charging work or will I need a special charger for this type of battery? Any help would be greatly appericated

If you're up to building your own, the Chinese LFP modules are working out very well, according to my cousin who used a Nissan Leaf battery to power their bus conversion. They said that, if they were to do it again, they'd use these modules instead of the Leaf's. The ones their friends used for their off-grid homestead are 280Ah =each=, and they installed 32 modules, for 29 kwh. From what my cousin has told me, for an RV, with only a few modules, you probably wouldn't even need to add a BMS (battery monitor system); not that you =can't=, just not really necessary.

Lyle

LiFeP04 battery is close to 100% SOC at 13.6-13.7v Lithium chargers do charge at a higher voltage but that is more of a function of charging faster than being fully charged. If you look at the charge curve for LiFePO4 you are talking less than 1 or 2 % above 13.7v A stock Progressive Dynamics converter charger has a 13.6v output.

In short your stock converter charger will charge a lithium battery. Pretty much all the battery manufacturers include this fact in their literature. It will take longer than a LiFePO4 charger as it tapers current through stages.

Have a look at the charge curve and you will see that 13.6v is essentially 100%


Click For Full-Size Image.

before you do anything get the book out for your set up and see what the specs are. maybe you have one that all you have to do is "switch" it to a lithium setting.

I know personaly if I were you, 9 out of 10 times I would change out the charging section of your converter if it is the one that came with the trailer because they are normaly junk and just kill batteries if you leave them pluged in during the off season like I do.

if not like mentioned above they will work kinda, is it optimal for the battery , nope. would I leave it pluged in for months on end , nope but you can make it work lots of people do.

Steve

The bigger issue is the float voltage. After a LiFePO4 battery is fully charged you want the float voltage to be no higher than what the manufacturer recommends. If your converter doesn't float at or below that voltage then just turn it off until you need to charge it again.

The OEM converter will work perfectly fine. Don't get all caught up in buying a "lithium" converter.
Post your existing converter model for best answers.

Lithium battery has more energy stored in them at 90% than a fully charged lead acid battery at 100%.
Lithium batteries are charged to 14.6 volts Lead acid are charged to 13.2 typically.
BattleBorn batteries are Guaranteed 10 years. typical for Lithium.
The lithium won't corrode posts like lead acid.
same size battery lithium will be 50% lighter
study the U-tube videos about "BattleBorn batteries"

The OEM converter in your RV will charge a LiFePO4 battery - but not all the way. It won't hurt it though. You just won't get full use out of the lithium battery. I switched out the OEM converter/charger in our rig when I installed the lithium batteries - no big deal.

Rob