2S3P battery balancer wiring diagram

[JRA]

Could anyone provide a wiring diagram pic for connecting a battery balancer(s) to a 2S3P 24v system.I was planning on the Victorian but am reconsidering. Here are the issues I am having. Admittedly I have some cognitive issues so maybe I’m just not getting it.
1 How many controllers will I need. I see diagrams of 2S2P systems with 1 controller with pos/neg from balancer going to associated terminals of the top batteries. I’ve read threads where it is recommended to have 1 controller per series bank, so 3 controllers for a 2s3p system?
2. With 3 controllers would I wire 1 controller to each series bank? Essentially treating each of the 3 series banks as individual systems.
3. Space is an issue. Are there any decent balancers that can control multiple batteries?
4. In a video I watched it was recommended to fuse pos/0v/common from balancer. Is it necessary to fuse the 0v wire?
5. Other than the 4 battery in parallel limitation is there a benefit to a 2S3P system over just using a step up converter.
I know these questions have been asked but it seems like there are multiple opinions and maybe multiple “correct” ways to connect. A visual works best for me. I’m just not getting that click moment.

 

[HRTKD]

If you need a 24 volt system, build a 24 volt battery. Don't fool around with putting 12 volt batteries in series.

You need as many controllers that will balance 6 batteries. Ideally, you want one controller so that it evenly balances all batteries in the battery bank. When you use multiple controllers they don't know what the other controller is doing. Since a 6 battery balancer probably doesn't exist then you want three controllers, one for each series string.

 

[JRA]

Thanks, I appreciate the reply. I get it about building a 24v battery but it’s still cheaper to buy 2 12v batteries over an equal 24v battery currently.I got a good deal imo on the 6 12v batteries. I don’t have the space to build my own anymore so prebuilt is the way I have to go.
If I go with the Victron controllers it looks like they can be connected in parallel so I think that suggests they would all be communicating with each other but there are mixed opinions on quality. That’s probably true for just about any equipment today though.
So if I went with 3 controllers I would connect 1 controller to 1 series bank with the common connected to the whatever middle series bank terminal? Then connect the controllers in parallel?
I absolutely agree with you that just going 24v from the start is the best ands easiest way. It’s just not a possibility right now and I want to use all six batteries in a single configuration. If I could just run the six in parallel I would just do that and add a step up.

 

[HRTKD]

The Victron Battery Balancer manual has images of different situations. The 2s3p scenario that uses a single Battery Balancer has me confused because it looks like it is balancing between the three series strings, not balancing individual batteries.

https://www.victronenergy.com/upload/documents/Manual-Battery-Balancer-EN.pdf

 

[mikefitz]

1 How many controllers will I need.

One per string.

2. With 3 controllers would I wire 1 controller to each series bank?

Yes.

3. Space is an issue.

You could connect three batteries in parallel , then wire in series with the remaining 3 in parallel, needs one balancer.

4. In a video I watched it was recommended to fuse pos/0v/common from balancer

Would be a safety feature, fuse as near the battery as possible.

5. Other than the 4 battery in parallel limitation is there a benefit to a 2S3P system over just using a step up converter.

Why do you need 24 volts?

Picture 24 volt system with two 12v batteries, needs one balancer,

Connecting batteries in parallel before the series connection, picture shows 6 batteries. Needs one balancer. Shunt shown is optional


In the single balancer circuit the batteries in parallel self balance. This configuration is more suitable to lead acid batteries.

Why do you need 24 volts and what battery type are you using?

 

[JRA]

The Victron Battery Balancer manual has images of different situations. The 2s3p scenario that uses a single Battery Balancer has me confused because it looks like it is balancing between the three series strings, not balancing individual batteries.

https://www.victronenergy.com/upload/documents/Manual-Battery-Balancer-EN.pdf

Yes, that is the same thing causing some of my confusion.
It cost some coin but it would seem using 3 controllers presumably wouldn’t hurt anything and the controllers can be run in parallel. It seems like the optimal option even if not necessary. I still think it’s considerably cheaper to buy 6 12v batteries and 3 contollers for a 2s3p 24v configuration than to buy 1 24v 300ah battery. More of a PITA and some efficiency loss for sure though.

 

[JRA]

Yes, that is the same thing causing some of my confusion.
It cost some coin but it would seem using 3 controllers presumably wouldn’t hurt anything and the controllers can be run in parallel. It seems like the optimal option even if not necessary. I still think it’s considerably cheaper to buy 6 12v batteries and 3 contollers for a 2s3p 24v configuration than to buy 1 24v 300ah battery. More of a PITA and some efficiency loss for sure though.

Sorry I didn’t see your whole response.

One per string.

Yes.

You could connect three batteries in parallel , then wire in series with the remaining 3 in parallel, needs one balancer.

Would be a safety feature, fuse as near the battery as possible.

Why do you need 24 volts?

Picture 24 volt system with two 12v batteries, needs one balancer,
View attachment 255935
Connecting batteries in parallel before the series connection, picture shows 6 batteries. Needs one balancer. Shunt shown is optional
View attachment 255939

In the single balancer circuit the batteries in parallel self balance. This configuration is more suitable to lead acid batteries.

Why do you need 24 volts and what battery type are you using?

I want 24v to eventually connect a 24v inverter to run a portable AC for the times it gets too hot for my dog. The AC draws around 900-1000 on high. It’s really just an efficiency thing.
Am I correct that properly sized 24v inverter would run cooler and more efficiently?
To be honest I want to configure the 6 batteries so I can have another set of problems to learn from so I can help somebody else in the future. Hopefully free lessons.

 

[JRA]

Sorry I didn’t see your whole response.

I want 24v to eventually connect a 24v inverter to run a portable AC for the times it gets too hot for my dog. The AC draws around 900-1000 on high. It’s really just an efficiency thing.
Am I correct that properly sized 24v inverter would run cooler and more efficiently?
To be honest I want to configure the 6 batteries so I can have another set of problems to learn from so I can help somebody else in the future. Hopefully free lessons.

Thanks for the response. I’m certain that I’m overthinking it.
So in the pic you attached from Victron. Would I just connect the wires as shown to the top bank closesr to the balancer. Then I just imagine 2s2p connected to that, is that correct?

 

[MisterSandals]

so I can have another set of problems to learn from so I can help somebody else in the future. Hopefully free lessons.

You'll be in a group that consists of almost everybody here.

 

[Koyaanisqatsi]

Buy two more batteries and set everything up as 48V (4s2p needs two 4-cell balancers or 2p4s needs 1 4-cell balancer.). If you have not bought 24v inverters yet, you'll be a lot happier with 48V over 24V, esp if you expect to run a AC unit from it in the future. And stepping down from 48v to 12v is the same as 24v to 12v. But everythign else will be easier to work with and use wires that are thinner and easier to work with.

 

[JRA]

One per string.

Yes.

You could connect three batteries in parallel , then wire in series with the remaining 3 in parallel, needs one balancer.

Would be a safety feature, fuse as near the battery as possible.

Why do you need 24 volts?

Picture 24 volt system with two 12v batteries, needs one balancer,
View attachment 255935
Connecting batteries in parallel before the series connection, picture shows 6 batteries. Needs one balancer. Shunt shown is optional
View attachment 255939

In the single balancer circuit the batteries in parallel self balance. This configuration is more suitable to lead acid batteries.

Why do you need 24 volts and what battery type are you using?

Sorry if I’m all over the place with my responses.
Thank you. You made it click. Each bank in parallel balances themselves and 1 controller balances the banks in series. That should have been more obvious to me.
Can I ask if using 3 controllers, 1 on each set, would do any harm or have even a little benefit? Taking the cost out of the equation. Is this absolutely ridiculous? I’ve seen other responses saying 3 are necessary but maybe I’m confused as to what configuration I was looking at.

 

[JRA]

Buy two more batteries and set everything up as 48V (4s2p needs 4 balancers or 2p4s needs two balancers.). If you have not bought 24v inverters yet, you'll be a lot happier with 48V over 24V, esp if you expect to run a AC unit from it in the future. And stepping down from 48v to 12v is the same as 24v to 12v. But everythign else will be easier to work with and use wires that are thinner and easier to work with.

Thanks. I actually was considering that exact option. I also use the banks to charge a couple of power stations so 48v gets the job done faster.
I currently use step up converter with the proper amp rating to charge the power stations.

 

[HRTKD]

It would have to be a rather hefty step up converter to power an inverter.