Do I just need a DC-DC charger to charge lithium?

[Oceanride007]

https://www.victronenergy.com/batter...tery-isolators


Not used one but would work.


B2B charger, from LA to LFP would be also good.

[kirklkjb]

I do agree with the comment "does nothing to protect a small case alternator from overheating". A DC-DC charger or an all in one system is a better solution in that case. Also, do you have experience with the LIM? Given lead acid charging profiles are voltage based and they have an algorithm and sensors to control both sides I can see how they could manage the charge to the lead acid battery. I'm not so sure about the LI side but if they don't attempt to charge the LI battery to 100% but limit it to a lower voltage level and lower charge level I can see how the Li side can be managed via just a voltage sense. Would be good to know more about their sensor system and get some user feedback on it before discarding a system specifically designed for lead acid starter + LI house system.

[kenbo]

Originally Posted by kirklkjb

I do agree with the comment "does nothing to protect a small case alternator from overheating". A DC-DC charger or an all in one system is a better solution in that case. Also, do you have experience with the LIM? Given lead acid charging profiles are voltage based and they have an algorithm and sensors to control both sides I can see how they could manage the charge to the lead acid battery. I'm not so sure about the LI side but if they don't attempt to charge the LI battery to 100% but limit it to a lower voltage level and lower charge level I can see how the Li side can be managed via just a voltage sense. Would be good to know more about their sensor system and get some user feedback on it before discarding a system specifically designed for lead acid starter + LI house system.

I agree it would be very good to know more about their technology but their datasheet does nothing to explain how the product works. AFAIK SOC measurement is a bit more detailed than voltage measurement for both LA or LiFePO4 chemistries. But if you find the product useful that's fine for me.

[CarlF]

I agree that the OP would be better served replacing his single house battery with a Firefly.

With a Firefly you can do the same 80% discharge as a lithium battery without damage. There's also no worry about PSOC (partial start of charge) damage. And no special alternator protections are required - although a good external regulator like the Balmar 614 with both battery and alternator temperature sensors is always a good idea and will get more amps out of the alternator without damaging it.

Firefly's are about 1/2 the cost of a Battleborn and should last 7-8 years.

If the OP's house bank was 400AH or more, lithium might then be a better idea.