Best budget smart active battery balancer? Or should I even use one?

[Tuna!]

What is the best budget active battery balancer?

Or should I even use one?

I’m going to build a 24v solar system for my campervan. I have 2 used LiTime 12v 200Ah batteries I will wire in series. The batteries aren’t very old and were used together by the previous owner only for a summer.

I was looking around and there are way too many battery balancers to choose from. The Victron one is only 1amp at best. Also I have heard that having an active balancer without some kind of smart system will actually unbalance the batteries if left running for a long period of time.

 

[BentleyJ]

Each 12V battery probably already has an internal balancer for its 4 cells. There is really no way to balance all 8 cells as a set unless the cases are opened up on each of the 2 batteries and an 8S balancer attached. Not sure this is even possible as it may interfere with the built in BMS balancer.
Alternate would be take all 8 cells out of the LiTime cases and build your own 8S battery with a new 8S BMS and balancer designed for a 24V system.

Best to just connect your 2 x 12V batteries is series and let the internal BMS take care of things without adding anything. When those batteries need to be replaced then a 24V model can be purchased.

Would be a good idea to first top balance the 2 batteries by connecting them in parallel and charging at 14V overnight.

 

[740GLE]

The victron 12vx2 balancer at 1a while seems small is still plenty to keep a two 12v batteries in series well balanced.

Battery Balancer - Victron Energy

Equalize the state of charge of two series connected 12V batteries using the Battery Balancer. Find a Victron Energy dealer near you.

www.victronenergy.com

Remember on a normal charge/discharge the balance won’t be that bad so if you’re chipping a little bit away each day it’ll remain happy. Just make sure the system voltage is always getting high enough for the balancer to work its magic

It’s the set ups that have nothing to keep the systems in check that have issues months/years down the line.

 

[mikefitz]

way too many battery balancers

It's possible there is a confusion between battery balancers, ( that ensure the mid-point voltage of two 12v batteries in series is maintained at mid point level), and cell balancers , (that operation the individual cells in the battery).

Where two 12v batteries are in series, a difference in SOC will develop, eventually causing issues. The mid point battery balancer will ensure that the batteries remain in balance. One amp is more than enough operating continuously.


edit
Sorry to post a similar reply, I type slow.

Mike

 

[timselectric]

Or should I even use one?

It saves you from having to do it manually, every few months.