Good day everyone

I recently purchased the Mercer sol-i-ax-3m plus 24 inverter with 2 12v deep cycle batteries (105ah) in series (it is a 24v inverter). So far everything works well.

I was wondering if I can connect 2 additional batteries (2 in series for 24v, and then another 2 in parallel) so I can run for longer on battery power? Do I have to get a BMS if I want to do this because in my mind all batteries will get charged to the same voltage, but what if a battery is damaged and it cannot charge to the correct voltage?

Perhaps I am overthinking this but I figured it will be better to ask someone with way more experience than me before I pull the trigger and buy 2 additional batteries.

Best regards

 

Edited December 2, 20214 yr by necrolingus

Yes you can. Just make sure they are matching batteries (make,model,rating etc). How old/healthy are the current 2 batteries? Have they seen much life (charge/discharge)

You will likely learn that best practice dictates adding new to old isn't recommended, might want to factor that in. Your inverter has all the necessary capability of managing the battery bank. One of those Victron BMV's added won't hurt though

Thanks for the super quick reply and the valuable insight. 

The current batteries are about 2 weeks old now so still fresh. I'll make sure to get the same make and model. 

Let me read up on the Victron BMVs a bit. Thanks!