Is B-B charger for Lifepo4 lithium batteries needed?

RLS7201 wrote:
Grover, I believe you're on the right track if your new batteries have a built in charge controller. As far as alternators not being able to fully charge house batteries, that's non-¢. A steady charge at 14 volts for a full day of driving will fully charge lead/acid house batteries. If you are concerned about over heating you alternator with Li batteries, why not put a temperature sensor on the alternator before and after the battery change and see what happens. I see so much hype about burning out alternators but no solid evidence.

Richard

1. 14 volts will NOT fully charge a lead acid battery in a full day of driving. It is unlikely unless there is a dedicated alternator that 14 is available for the entire day.

2. Victron has a different opinion that yours on burning out an alternator.

https://www.victronenergy.com/blog/2019/10/07/careful-alternator-charging-lithium/

RLS7201 wrote:
A steady charge at 14 volts for a full day of driving will fully charge lead/acid house batteries.

Modern vehicle alternators will NOT supply "14 volts for a full day". Most will cut back to about 13.2V after 5-10 minutes of driving.

This another reason to purchase a DC-DC battery charger. It will actually BOOST the voltage up to the amount to properly re-charge your batteries.

With an adequate solar system, including a controller suited to lithium, you’ll rarely need to fire up the generator.

Grover, I believe you're on the right track if your new batteries have a built in charge controller. As far as alternators not being able to fully charge house batteries, that's non-¢. A steady charge at 14 volts for a full day of driving will fully charge lead/acid house batteries. If you are concerned about over heating you alternator with Li batteries, why not put a temperature sensor on the alternator before and after the battery change and see what happens. I see so much hype about burning out alternators but no solid evidence.

Richard

Groover wrote:
The second argument for the B-B charger is that the engine alternator will not fully charge the lithium battery.

Vehicle alternators are designed to charge the lead acid starting battery, not LiFePO4 ! They don't even do a good job of recharging a lead acid "house battery bank". The output voltage from your alternator and voltage regulator are not designed for LiFePO4.

MountainAir05 wrote:
I would say yes to you need some type system to charge the battery pack.

CONCUR !

Just make sure to purchase a DC-DC charger that has a programmable output for both lead acid and LiFePO4.

First off the alternator is there to maintain the battery not fully charge them. I would say yes to you need some type system to charge the battery pack. I no long have our RV , but when I change over from 10 battery system to a 4 lithium battery system it came with a charger. Within 3 months it fried. They install a newer one different maker and we ran it for another year without a issue. I do not know about the B to B charger that you are talking about. The one in my RV took up the space of 3 battery space. They put it in with a fork due to weight.

If you feel you do not need it don't put it in. If your system burns out then you will know you need one. The people who make these system should know what they need in it so it will work and last. I purchase my complete system from a place in Phoenix Az. Sorry I do not remember the name, all paper work went with the RV when sold. I do know that the system is still working due to the fact the new owner sent us a Christmas card letting us know everything is working well on the Coach.

This is one of the places that I contact and got info along with the one in Az. https://enerdrive.com.au/.

The one in Az is not showing up on my web search so out of business or change there name.