Battery Types 201

There are 3 main types of batteries that I will talk about: Flooded, AGM and Lithium.

Flooded is the most economical battery type and for the most part will accept less charging current than others. They will need to be vented outside of the RV and will spill acid if not upright. They do come with household chores and will give off a gas (it is explosive in higher concentrations) as they charge. They will boil over their acid which forms corrosion and requires them to be refilled with distilled water. This is a normal part of using your Flooded batteries. You should equalize them every 2-8 weeks with a few factors determining the frequency. You will also need to check the specific gravity of the battery to determine the state of charge. There are many other resources for maintaining these batteries online. For all of the above reasons I will not use them in my RV.

I believe AGM is a better choice as their maintenance consists of checking connections 4 times a year and an annual capacity test.  Since they do not need to be vented, they have more flexibility with their location and can be placed in any orientation except upside down. A 100AH Lifeline battery will accept up to 500Amps during the Bulk stage, this is more current than most Lithium will accept.  I believe AGM is a great middle ground of battery choices.


Lithium can be a great choice with less weight and the ability to use almost of all of the stated AH capacity. It is not new technology but newer to the RV world. There are drop in replacements for most existing battery compartments. Llithium has the ability to accept higher charge current all the way through the charging cycle. It is important to have a Battery Monitoring System (BMS) with all Lithium batteries. The BMS protects the battery from catastrophic events. The BMS onboard of drop in replacements is not always enough protection to rely upon, there needs to be a main BMS in your wiring to disconnect the battery system as a whole.  

Leave a comment