i am cotemplating changing to house batteries on my yacht to lithium and leaving an AGM for enging battery. I have a small solar panel about 200w and an Air X wind generator. If I connect these up to the AGM battery only and use a dc to dc charger to connect to the lithium will by 100 amp alternator on my engine be able to charge say 2 times 100 amp or 2 times 200 amp lithium batteries? Or can some onesuggest a better way to do this?
A DC to DC charger is a good option, An Orion XS is the preferred option. A general rule of thumb is to charge lithium at no more than 2/3rds of the rated alternator capacity to avoid overheating it. If you fit a 50A Orion XS then you will be good and that is easily OK for 200 to 300Ah of lithium.