# Charging 4 12V deep cycle marine batteries connected in series with a 24V wind generator

How can I charge 4x 12V Marine Deep Cycle batteries connected in series with a 24V Wind Generator?

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Duplicate of electronics.stackexchange.com/questions/38212/… –  HikeOnPast Aug 21 '12 at 19:53

If you want to charge all 4 at once you need a boost converter, with the output of the WT (Wind Turbine) converted to DC.

AC feed is not suited to direct conversion due to variable voltage with wind speed and (usually) variable frequency.

If the WT output is floating relative to the batteries you could charge each in turn by driving the floating battery junctions one at a time.
eg B1A-B1B - B2A-B2B - B3A-B3B - ...

So eg Battery 2 can be charged by connecting the floating charger to B1B-B2a and to B2B-B3A
Care would be needed to maintain balance.

Batteries in series:

Use of B1A, B1B etc is just an attempt to describe how the batteries are connected in a string.

Above I used B1A = Battery1 +ve, and B1B as Batery1 -ve, as the + and - signs tend to get overlooked when writing long strings.
eg showing a series of connected batteries as: B1+ - B1- - B2+ - B2- B3+ is unclear. :-(

A series string can be shown as:

---(B1A-B1B)---(B2A-B2B)---(B3A-B3B)--- ....

The junction between B1 and V2 is the connection of B1B and B2A
So to connect to battery B3 in a string of batteris B1 B2 B3 B4 B5 you want to connect to B3+ and B3-.
It would have been clearer if I'd said that in that case.
As B2B is connected to B3A and as B3B is connected to B4a, to connect to battery B3 we connect:
B3+ = B2B = B3A
B3- = B3B = B4A.

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Thank you so much taking your time to answer my question. It's actually 8 batteries (2 sets of 4 in series connected in parallel) I provided a drawing how I have it now. I haven't finished connecting them, wanted to run it by someone. I also don't like all those switches and I have them charging in pairs to simplify the job. I do have a charge controller for my WT and solar panel, hybrid. At the moment I'm charging them with 3 120V shore chargers (each battery individually). I hope this is enough info. if not, please, don't hesitate to ask. Thank you again very much. –  Alexei Afonin Aug 22 '12 at 2:00
I also am not sure what you mean by B1B? I guess –  Alexei Afonin Aug 22 '12 at 12:41
I guess first "B" stends for Battery, "1" - for First Battery, but what second "B" stands for? "+" or "-"? –  Alexei Afonin Aug 22 '12 at 12:43