Connecting 8 batteries for my house bank

[Bruce Palmer]

Hello All
There appears to me to be two main ways to connect 8 6v batteries to make a 12v bank, or 8 12v to make a 24v bank.
Plan A:* pair each battery with another in series, making 4 pairs, then parallel all the four pairs, or,Plan B Parallel two sets of four batteries, then connect in series the two sets.I don't see why both ways not would work, but is there a preferred*way and why?
Thanks - Bruce

 

[SteveK]

Bruce, a lot of battery threads around here. Perhaps if your question was specific instead of alternates you may get more replies. You either need a 12V or a 24V bank, usually not both or options of both.
6 volt FLA have in past been the choice for deep cycle for longer lasting.
Kindly stick to building a system that suits your needs, 12v or 24v

 

[luna]

Bruce.

Either way, Series/Parallel or Parallel/Series would work, but the S/P method offers the following benefits, provided you wire it with the hub and spoke method.

- The current on any one conductor (up to the Buss bar) is kept to a minimum, as a result smaller conductor size can be used to acheive the same voltage drop goal.

-I you lose one pair of batteries, you only lose only 1/4 of you bank capacity, compared to 1/2 the bank in a P/S configuration.

-With most Golf Cart batteries it's easier and neater to wire in series as you don't have to wire around the battery caps.

 

[Bacchus]

Bruce.

Either way, Series/Parallel or Parallel/Series would work, but the S/P method offers the following benefits, provided you wire it with the hub and spoke method.

-I you lose one pair of batteries, you only lose only 1/4 of you bank capacity, compared to 1/2 the bank in a P/S configuration.

-

Can you explain the 1/4 vs 1/2 capacity?
If one 6V batty goes bad you should drop a pair in either case... I dont understand the logic but happy to listen & learn?

 

[luna]

Bacchus.

I can understand why you don't understand the logic, as my statement regarding losing 1/2 the bank capacity is in this instance entirely wrong.
You would, as you note have to isolate one pair of batteries if you wanted to keep the capacity of the 2, 6V strings equal.

Somehow while typing this nonsense, I concluded that this 4p2s configuration acts the same as my 4s2p 24V bank that does lose 1/2 the capacity if one 6 V battery goes bad.

I will try in the future to think first, then type.

 

[Bacchus]

Luna
Thanks for clarifying.
I listened and did learn why, in your configuration, you would lose 1/2 of the capacity. I could not think of a case of how that would be possible but I forgot not everyone has a 12V system and lots of boats with 24V & 48V systems. The devil is in the details as is frequently the case.
In any case... no harm... no foul

 

[Delta Riverat]

12 or 24, I would series 2 each and parallel the ends. With nice copper bars if possible.