Can I Replace My Lead-Acid Battery With a Lithium Battery?


I purchased a boat with a lead-acid battery.  I would like to add a second battery using lithium.  It is my understanding that I cannot combine battery chemistries, i.e. lead-acid and lithium.

If I replaced the lead-acid battery with a lithium battery, do I just connect the engine to the new battery? That seems too simple to be right.  - Thao


You are correct, you cannot combine two battery chemistries. 

We would suggest going with lithium for your house or auxiliary battery loads and sticking with an AGM or lead-acid battery for the starter. You can recharge the lithium batteries with a DC to DC charger from the engine battery to the house lithium battery.  

Lithium requires a very specific set of voltages to be safe, so ensure your charge sources are set up correctly.