3 parallel Lead Acid strings

[dapago]

hello to the community,

I have a battery bank composed of 12x6V batts for a 24V solar system wired 4S3P.
I am a bit worried not to be able to balance properly the second serie of 4 batts (in the middle).

I have found 2 diargrams that allow to perfectly balance a serie of 4 + batts but do not know how to apply those diagrams to batts wired in parallel. Someone could help?

i have attached a picture to show the 2 options proposed. For the full article relating to those wiring, please refer to http://www.smartgauge.co.uk/batt_con.html 37340560-A503-40FA-8AC5-74075504847E.gif
37340560-A503-40FA-8AC5-74075504847E.gif

thank a lot.

[NEOH]

Each one of those "batteries" in your diagram should be treated as one String of "4 batteries in series".
Each block is a 24 Volt Pack.
The picture shows 4 strings in parallel, you would have 3 strings in parallel.

[dapago]

Each on of those "batteries" in your diagram should be treated as one String of "4 batteries in series".
Each block is a 24 Volt Pack.
The picture shows 4 strings in parallel, you would have 3 strings in parallel.

Hi there. Sorry I did not get your message. It seemed to me the diagrams I shared showed 1 string of 4 batts in serie. My issue here is to apply one of those diagram to wired 12 x 6V batts as 4 en serie and 3 parallels.

Maybe instead of applying on of those diagrams I shared I could use bus bars and balanced properly the bank. If the busbar method is acceptable for a perfect balancing, I just need someone to send me the wiring diagram to achieve it.

[SunEagle]

Hi there. Sorry I did not get your message. It seemed to me the diagrams I shared showed 1 string of 4 batts in serie. My issue here is to apply one of those diagram to wired 12 x 6V batts as 4 en serie and 3 parallels.

Maybe instead of applying on of those diagrams I shared I could use bus bars and balanced properly the bank. If the busbar method is acceptable for a perfect balancing, I just need someone to send me the wiring diagram to achieve it.

To clarify both of those diagrams you provided are 4 "batteries" wired in PARALLEL not in series.

To wire your 12 x 6v batteries you would wire 4 batteries in series and then do it again for the next 4 batteries and then the final 4 batteries.

You would then wire those 3 sets of 4 in parallel similar to what is in your diagrams but only having 3 "batteries" in parallel instead of the 4 shown.

You can either use a bus bars or the same length wire for the parallel connections.

Does that help you understand how to wire your 12 batteries?

[NEOH]

The EXAMPLE diagram below shows 8S3P ...
8 Batteries in each series string
and then 3 strings connected in parallel with equal length cable or copper bus bar

You will have 4S3P ...
4 Batteries in series for 24 volt = 4 x 6 volts each
and then 3 strings connected in parallel with equal length cable or copper bus bar

http://solarhomestead.com/deep-cycle-battery-maintenance/

[dapago]

To clarify both of those diagrams you provided are 4 "batteries" wired in PARALLEL not in series.

To wire your 12 x 6v batteries you would wire 4 batteries in series and then do it again for the next 4 batteries and then the final 4 batteries.

You would then wire those 3 sets of 4 in parallel similar to what is in your diagrams but only having 3 "batteries" in parallel instead of the 4 shown.

You can either use a bus bars or the same length wire for the parallel connections.

Does that help you understand how to wire your 12 batteries?

hello. Neoh just sent me a diagram after you post. With the diagram I do understand it better now. The diagram NEOH just sent is similar to the method 3 I have shared but with 12 batts instead of 24. . The only difference with NEOH diagram (if I well understand it) is that the ends cables (thick red and black ones) will connect to a bussbar if I want to use them. Am I correct?

[SunEagle]

+1 Nice diagram NEOH.

[SunEagle]

hello. Neoh just sent me a diagram after you post. With the diagram I do understand it better now. The diagram NEOH just sent is similar to the method 3 I have shared but with 12 batts instead of 24. . The only difference with NEOH diagram (if I well understand it) is that the ends cables (thick red and black ones) will connect to a bussbar if I want to use them. Am I correct?

You are correct about the bussbar connection location.

[dapago]

The EXAMPLE diagram below shows 8S3P ...
8 Batteries in each series string
and then 3 strings connected in parallel with equal length cable or copper bus bar

You will have 4S3P ...
4 Batteries in series for 24 volt = 4 x 6 volts each
and then 3 strings connected in parallel with equal length cable or copper bus bar

http://solarhomestead.com/deep-cycle-battery-maintenance/

Great! As I answered SunEagle, I think the diagram you shared correspond to the method 3 I shared (see my reply to suneagle) but lot more clearer for me Thank you very much!
What I can see as well on your diagram is that the batts are as well tied together (dot lines). That makes a lot of cables but if that will allow my bank to balanced properly then I will go for it.

[NEOH]

Those dotted lines (bank balancing wires) are not used for lead acid
Typically, the balancing wires used for lithium ion, only

[dapago]

Those dotted are typically not used for lead acid
Typically, used for lithium ion

So I don

[dapago]

My answer is not showing On my iPad
will open a new message.
i was asking that if the dot lines are not necessary, will the bank be well balanced?
if not, can we use method 4 and if so what will be the diagram?
sorry to bother you again

[inetdog]

My answer is not showing On my iPad
will open a new message.
i was asking that if the dot lines are not necessary, will the bank be well balanced?
if not, can we use method 4 and if so what will be the diagram?
sorry to bother you again

For lead-acid batteries you do NOT want to add the cross connections (dotted lines). The batteries and strings will be better equalized if you do not use them.
For lithium chemistry batteries, which do not tolerate overcharging some batteries in a string to get full charge on others, you would want to use the cross connections.

[Sunking]

So I don

You can connect Pb batteries as show below (Alternative) IF THE CELLS ARE 2 VOLTS. They cannot be 4, 6, 8, 12, 24, or 36 volt Pb batteries which is shown Conventional.

[dapago]

For lead-acid batteries you do NOT want to add the cross connections (dotted lines). The batteries and strings will be better equalized if you do not use them.
For lithium chemistry batteries, which do not tolerate overcharging some batteries in a string to get full charge on others, you would want to use the cross connections.

Thanks a lot for your inputs!!! Really appreciate it.