Do i need a BMS for series batteries ?

[bbonk]

Newbie here,

Im wondering if you series or parallel battery banks which already have BMS, do you need a BMS for the final configured battery bank?

Say for instance if you series up 4 of the SOK batteries for a 48v system (4x12v): https://www.sokbattery.com/products/100ah-12v-lifepo4-deep-cycle-battery

would I need a BMS for the 48v battery if im connecting it to an all in one solar device such as the Hybrid LV6048 ?

Any clarity provided would be much appreciated. thanks!

 

[Diysolar123]

nope
it would be a good idea to monitor the existing BMS units if possible, if not, you should attach a something to let you watch total voltage and temp.

 

[snoobler]

Welcome to the forum.

There's really not such a thing, but there are 12V balancers that monitor each 12V and actually move current from high to low rather than bleeding it off.

Amazon.com: Battery Equalizer 48V - Battery Voltage Balancer,for 4×12V or 8×12V or more Battery Bank Extend Battery Life 1 Year and More, support Gel Flood AGM Lithium Battery HA02 Balancer(Battery Equalizer 48V): Industrial & Scientific

Buy Battery Equalizer 48V - Battery Voltage Balancer, for 4×12V or 8×12V or more Battery Bank Extend Battery Life 1 Year and More, support Gel Flood AGM Lithium Battery HA02 Balancer(Battery Equalizer 48V): Energy Controllers - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

I have a 4S2P FLA bank built from old Trojans out of golf carts. These things keep the individual 12V nicely "balanced."

 

[Bob B]

Have you checked the specs of the SOKs to make sure they support 4 in series ..... I don't know .... but some do not or may support 2 in series but not 4.

 

[John Frum]

Each SOK battery has a built-in BMS.

 

[Brassburnz]

Welcome to the forum.

There's really not such a thing, but there are 12V balancers that monitor each 12V and actually move current from high to low rather than bleeding it off.

Amazon.com: Battery Equalizer 48V - Battery Voltage Balancer,for 4×12V or 8×12V or more Battery Bank Extend Battery Life 1 Year and More, support Gel Flood AGM Lithium Battery HA02 Balancer(Battery Equalizer 48V): Industrial & Scientific

Buy Battery Equalizer 48V - Battery Voltage Balancer, for 4×12V or 8×12V or more Battery Bank Extend Battery Life 1 Year and More, support Gel Flood AGM Lithium Battery HA02 Balancer(Battery Equalizer 48V): Energy Controllers - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

I have a 4S2P FLA bank built from old Trojans out of golf carts. These things keep the individual 12V nicely "balanced."

I have four used Ironworks 12v batteries. I charged all four to 13.60v. I haven't run a capacity test. Before connecting them 2S2P for a 24v system, would the 24v version of the balancer you linked provide an additional benefit?

 

[snoobler]

I have four used Ironworks 12v batteries. I charged all four to 13.60v. I haven't run a capacity test. Before connecting them 2S2P for a 24v system, would the 24v version of the balancer you linked provide an additional benefit?

There are ones for 24V as well.

 

[bbonk]

awesome! thanks for the help.

Have you checked the specs of the SOKs to make sure they support 4 in series ..... I don't know .... but some do not or may support 2 in series but not 4.

yes, the specs say they support 48v series setup.

Connect in series for 24V or 36V or 48V Battery Bank, or Connect in Parallel for Larger Capacity.