Originally Posted by afelsoci
I am going to upgrade my Monaco Monarch 30 se to Lithium batteries. Looking for most cost effective way to change charger ,inverter and dc-dc charger. i purchased 2ea Lion energy batteries so far
The lowest cost method is to reset the existing built in charger to a Li compatible charging profile and to disconnect engine charging.
Late model RV chargers typically have a Li charging profile. Older models do not. Some older models will work with 200 amp hours of LiFePO4. Get make and model of built in charger and check with Lion for best advice. Performance of the batteries may not be optimum. 10 year old model chargers are hopeless. Replace them.
There may be performance benefits to getting a new built in charger. One is a purpose designed charging profile. Getting proper cell balancing at the end of a charge cycle is important for Li battery performance.
Two is getting a higher capacity charger. A 100 amp 12 volt charger will probably charge 200 amp hours of Li batteries twice as fast as a 50 amp charger.
Lithium battery manufactures usually prohibit charging lead acid batteries with their lithium batteries on the same circuit. Charging lithium house batteries from the engine alternator at the same time as charging the lead acid start battery is forbidden.
A 200 amp hour Li battery bank can draw more than 100 amps from an engine alternator. This will over heat a 130 amp engine alternator, especially when the engine is idling. A B2B charger with a Li charging profile can be connected to an engine charging system. It will limit the charge current and prevent overheating.
When a Li battery bank BMI disconnects while charging for one of many reasons, the alternator can spike a very high voltage, destroying 12 volt electronic including alternator controls engine computer systems. A cheap voltage clamping device can be connected to the alternator to suppress the possible voltage spikes.