LiTime 48V Battery Balancer For 24V/36V/48V Battery Bank

[sun_of_a...]

I wonder if anyone has any thoughts, warnings, comments about using this product to balance LiTime 12V 230Ah Plus LiFePO4s? And it's true this Balancer can be used to balance 24v banks of these 12v batteries, as well as 48v banks of them? Thank you!

(ps, I would provide a link, but I don't know if this is against the rules about posting affiliate links. Not sure I understand that rule... I'm... unaffiliated )

 

[timselectric]

If you can't gain anything from the link, you can post it.

 

[robbob2112]

The product is a good active balancer for series connected batteries. If you have 4 batteries and put them in 2s2p for 24v it will only have 2 of the leads connected so you may as well get the cheaper 2 lead version. If you are doing 48v as 4s then it connects to each battery.

Note - it does nothing for parallel connected batteries. They will come to equilibrium on their own.

If you do get it and connect the batteries in series start by fully charging all the batteries one at a time before stringing them together.

Ideally if you are doing 48v you would just buy a 48v battery and skip the balancer. I would only use something like this if I started with 12v and later decided to upgrade to 24v or 48v.

In fact I did start with 12v for a backup for my little cpap and then as a replacement for my UPS. But if I want the higher voltage the extra cost for new inverters and everything else means I would just get a 48v battery at the same time.

So, what is it you have now and what are you trying to do in future?

 

[sun_of_a...]

If you can't gain anything from the link, you can post it.

Hi Tim. I recall your comments about battery balancing issues to be aware of when putting LiFePO4s in series. I'm gonna use most of these 12v batteries in12v banks, but keep 4 of them for occasional use in series for 24v or 48v banks. Only occasional use with regular disconnection of series connections should mitigate battery imbalance problems and damage, shouldn't it? Thank you a lot!

 

[robbob2112]

Hi Tim. I recall your comments about battery balancing issues to be aware of when putting LiFePO4s in series. I'm gonna use most of these 12v batteries in12v banks, but keep 4 of them for occasional use in series for 24v or 48v banks. Only occasional use with regular disconnection of series connections should mitigate battery imbalance problems and damage, shouldn't it? Thank you a lot!

the balancer would eliminate the need to disconnect the batteries from the series connection. It balances all 4 in the string by taking a few amps from one and pumping it into the other until they are all even.

The passive blancers that are super cheap only take 0.5 amps from one to the other. So they take a lot longer and your batteries can drift far enough apart that you have to disconnect and charge each.

 

[sun_of_a...]

The product is a good active balancer for series connected batteries. If you have 4 batteries and put them in 2s2p for 24v it will only have 2 of the leads connected so you may as well get the cheaper 2 lead version. If you are doing 48v as 4s then it connects to each battery.

Note - it does nothing for parallel connected batteries.

Ideally if you are doing 48v you would just buy a 48v battery and skip the balancer. I would only use something like this if I started with 12v and later decided to upgrade to 24v or 48v.

In fact I did start with 12v for a backup for my little cpap and then as a replacement for my UPS. But if I want the higher voltage the extra cost for new inverters and everything else means I would just get a 48v battery at the same time.

So, what is it you have now and what are you trying to do in future?

Hi Thanks robbob. I have 16 230ah LiFePO4s that I'm mainly gonna use in 12v battery banks, but keep 4 of them for other configurations. I am not ready to buy 24v or 48v batteries yet, but a large bank of 48v batteries is the dream, ultimately.

 

[robbob2112]

Don't we all dream of that... massive banks of 48v batteries and large amounts of solar panels....

What appliction are you stringing them together to 24v and 48v for? What sort of inverters do you have for connecting things to your pretty large farm of 12v batteries? 16 x 230ah x 12v batteries is equivalent to 4 x 230ah x 48v .... that would power my house off grid for 4 days if my back of the napkin calculations are right.

 

[sun_of_a...]

the balancer would eliminate the need to disconnect the batteries from the series connection. It balances all 4 in the string by taking a few amps from one and pumping it into the other until they are all even.

My understanding is that series connection of 12v LiFePO4s like these for long term use even with good battery balancers is not a recommended practice because of battery imbalance problems.

 

[robbob2112]

My understanding is that series connection of 12v LiFePO4s like these for long term use even with good battery balancers is not a recommended practice because of battery imbalance problems.

That is and isn't true at the same time.

With passive balancers it is true, they typically can't keep up with the charge/drain cycles and never equalize before the cycle starts over..

With good active balancers that can keep up with your drain/drift you can run them like that as long as you want. Periodic checks of the voltages in the string will tell you how they are keeping up.

If they aren't then you can get better balancers (more amps) or you can determine the battery resistance of all 16 of your batteries and mix/match so each string of 4 is as close as you can get. A BMS inside the battery is doing basically the same thing with the cells inside, so it can be done. But, I would only do it if I got a screaming deal on the 12v and it was good enough to pay for the balancer and hassle

One reason not to do it is additional losses from the cables and connections and all the extra points of failure. So were it me I would oversize the cables a bit between the batteries and use No-Ox-ID on all connections except inside the lugs you crimp.

Another reason not to do it is all the extra exposed lugs and metal. For that I would do a MRBF fuse on the post of each battery and use rubber boots on all the connections. Make sure to size the fuses to 25% over what you expect to pull.

These two suggestions go for any way you connect the batteries up. Costs a bit, but saves on the havok a dropped wrench shorting things out would cause.

 

[timselectric]

Hi Tim. I recall your comments about battery balancing issues to be aware of when putting LiFePO4s in series. I'm gonna use most of these 12v batteries in12v banks, but keep 4 of them for occasional use in series for 24v or 48v banks. Only occasional use with regular disconnection of series connections should mitigate battery imbalance problems and damage, shouldn't it? Thank you a lot!

The only ways to mitigate the imbalance is to either use a battery balancer or be the battery balancer.

 

[sun_of_a...]

Don't we all dream of that... massive banks of 48v batteries and large amounts of solar panels....

What appliction are you stringing them together to 24v and 48v for? What sort of inverters do you have for connecting things to your pretty large farm of 12v batteries? 16 x 230ah x 12v batteries is equivalent to 4 x 230ah x 48v .... that would power my house off grid for 4 days if my back of the napkin calculations are right.

Before I go for a permanent install at home, I want to outfit 1) a 34 ft cargo trailer, 2) a 40 ft 5th wheel, and 3) a good size boat with solar panels. I have a bunch of rec365AAs. I already have two 24v inverter/chargers (AOIs); I'm planning on getting several 12v AOIs and several 48v AOIs as well. AC and DC HVAC systems. An example of a use of a 48v battery bank? There are affordable 48v electric outboard motors. Also, park the cargo trailer near the house, run extension cord to window unit a/c. Etc. The focus now is modularity and flexibility.

 

[sun_of_a...]

But, I would only do it if I got a screaming deal on the 12v and it was good enough to pay for the balancer and hassle

One reason not to do it is additional losses from the cables and connections and all the extra points of failure. So were it me I would oversize the cables a bit between the batteries and use No-Ox-ID on all connections except inside the lugs you crimp.

Another reason not to do it is all the extra exposed lugs and metal. For that I would do a MRBF fuse on the post of each battery and use rubber boots on all the connections. Make sure to size the fuses to 25% over what you expect to pull.

These two suggestions go for any way you connect the batteries up. Costs a bit, but saves on the havok a dropped wrench shorting things out would cause.

Thanks a lot robbob. I've already got the 12v batteries. I had originally planned to use them 4s4p for 48v, but decided to stick mainly to 12v battery banks b/c of potential imbalance problems. They are new, unused as yet.

 

[sun_of_a...]

The only ways to mitigate the imbalance is to either use a battery balancer or be the battery balancer.

Thank you timselectric. No time to be the balancer myself, since I've got my hands full trying to be the Buddha.

Okay, "mitigate," sure, but does a quality active battery balancer "solve" the battery imbalance problems going 4s4p w/ eg, 230ah 12v LiFePO4s, making them essentially like true 48v batteries themselves in terms of imbalance problems? Thank you.

 

[timselectric]

4s4p

Would need 4.
1 for each series string.

 

[timselectric]

Also need to verify that the battery manufacturer recommends 4s or not.

 

[sun_of_a...]

ok thanks Tims.

The product is a good active balancer for series connected batteries.

Thanks robbob. And thanks for the wiring suggestions for safety and robustness. Really. I'll probably have more questions about that. I've bought a lot of 1" x 1/4" pure copper flat bar to make big battery bars for big 12v banks.

 

[robbob2112]

Those bars are good for about 800amps, but I would be worried about them damaging the battery posts when you are driving.

 

[sun_of_a...]

Those bars are good for about 800amps, but I would be worried about them damaging the battery posts when you are driving.

I see what you're saying, but regarding these big mobile 12v battery banks, I was gonna use 2/0 cables from each battery to the battery bars (2 bars per battery bank, one +, one -) and connect from the AIO (mppt/inverter/charger) with a 2/0 cable to the middle of each +bar and -bar.

Thanks for helping me. I'm a novice for sure.

800amps, okay thanks for that info!

 

[robbob2112]

I see what you're saying, but regarding these big mobile 12v battery banks, I was gonna use 2/0 cables from each battery to the battery bars (2 bars per battery bank, one +, one -) and connect from the AIO (mppt/inverter/charger) with a 2/0 cable to the middle of each +bar and -bar.

Thanks for helping me. I'm a novice for sure.

800amps, okay thanks for that info!

Ok, that plan is good. I would still put MRBF fuse holders and fuses on all the positive posts.

Search for busman. Eaton, or littlefuse brands.... the cheap junk knockoffs on Amazon can be junk and the good stuff is typically renamed Eaton. Littlefuse, and busman.

 

[sun_of_a...]

Ok, that plan is good. I would still put MRBF fuse holders and fuses on all the positive posts.

Search for busman. Eaton, or littlefuse brands.... the cheap junk knockoffs on Amazon can be junk and the good stuff is typically renamed Eaton. Littlefuse, and busman.

Excellent, thanks so much robbob!