There are countless, conflicting and confusing opinions on charging LiFePo4 batteries. We've boiled our advice down to some guidance that isn't too complicated:
• Alternator charge voltage will bring a LiFePo4 up to 90% of its charge capacity. This is sufficient and cost effective for almost all customers, and will provide a long lifespan for these batteries.
• Our Auxiliary Battery Kits (AUX-700/701) kits are a great option for charging your LiFePo4 battery from the alternator and separating it from your starter battery.
• Solar chargers with AGM settings, as found in our Folding Solar kits, will work to charge our LiFePo4 battery.
• Our ProSport Chargers work great with these batteries.
• We know some customers will want to squeeze every last joule from their battery, recharge it without a second spared, and repeat this for every single cycle possible. There are aftermarket, no-dollars-spared solutions for you, but we’ve yet to find one we consider a good value.
There are some simple rules to follow for making battery banks with these LiFePo4 batteries:
• These batteries must not be connected in series with each other to create a system at 24V or higher. If an individual battery became unbalanced, its BMS would cause problems.
• These batteries must not be connected in parallel with lead acid batteries unless they're separated while not charging (for example, while using one of our Auxiliary Battery Kits).
• Multiple LiFePo4 batteries can be connected in parallel to make a larger LiFePo4 battery bank – a great option if you’re out camping for long periods of time without charging.
Finally, here’s some smart advice if you’re using a “smart” charger: The onboard BMS in our LiFePo4 batteries is a brilliant failsafe to keep your battery in good shape for a long lifespan. If your battery isn't charging it's likely the over-discharge protection has been engaged. We've seen rare occasions when the BMS's protective features prevented other "smart" electronics, like our ProSport charger, from recognizing the battery and charging it. If your battery seems stuck in a protected state, try using another source to recharge your battery until the protection is unlatched - we've never had problems getting a battery charged back up on a "dumb" 12V charger, or our Auxiliary Battery kits. Once the BMS protection is unlatched, the smart charger will be able to charge the battery again. Take a look at the "Battery Management System Specs" tab to see the set and release points for various protections.