the Otherpower.com Discussion Board || differing batteries

Front Page - [Homebrewed Electricity-- (wind) (solar) (hydro) (steam) (controls) (storage) (mechanical)] - Classifieds - Site News
Everything - Newbies - [Remote Living-- (housing) (heat) (light) (water)] - Rants & Opinion - Diaries - Our Products

differing batteries
By electrak, Section Storage Posted on Fri May 16th, 2008 at 07:41:30 PM MST
big or little

I have a question for persons more knowlageable then me, I have 7 deep cycles batterys of 450 AH and some golf cart batteries(200 AH), would it be better to sieres them 7+2 and have the smaller batteries work harder or 7+3 and have the brutes do the heavy work. I want 48 volts they are all 6 volts.
Thanks for your help
Dave

differing batteries | 5 comments (5 topical, 0 editorial)

Re: differing batteries (3.00 / 0) (#1)
by commanda (alwynne at unwired dot com dot au) on Fri May 16th, 2008 at 03:04:53 PM MST
(User Info)

Series the 7 x 450AH. Parallel 2 of the 200AH (= 400AH) and series this with the other 7.

Amanda

Re: differing batteries (3.00 / 0) (#3)
by electrak on Fri May 16th, 2008 at 05:37:14 PM MST
(User Info)

thanks, I wasn't sure if it would be better to use two of three

[ Parent ]

Re: differing batteries (3.00 / 0) (#2)
by dnix71 on Fri May 16th, 2008 at 05:36:46 PM MST
(User Info)

Amanda's answer is what I would give. You want all the batteries to do equal work, if possible. The down side of having that many batteries in series is that if one fails, you don't get much out of the bank.

If you could run 24 volts the system would be more fault tolerant.

Re: differing batteries (3.00 / 0) (#4)
by Flux on Sat May 17th, 2008 at 12:04:27 AM MST
(User Info)

It's a bad situation, but the answers the others give is the best compromise. The thing will most likely get out of balance and occasionally you will need to deal with it.

When one part of the string starts to show lower sg you will need to divert more charging current to it by putting a shunt load across the over charged bit until the low bit equalises. Most likely the string of 7 will need equalising and a lamp across the odd pair will reduce its charging current in relation to the others. Do it when you have good charging conditions.

Flux

[ Parent ]

Re: differing batteries (3.00 / 0) (#5)
by electrak on Sat May 17th, 2008 at 07:12:39 AM MST
(User Info)

Thanks for the advice, I have grid at the moment, looking to go to a time of use plan that can/will shut off power at times thoughout the day ( 14 hours minimum ) for 1/5 the rate.

differing batteries | 5 comments (5 topical, 0 editorial)

Menu

· create account
· How to use the board
· FAQs
· search the board
· Google search the board
· Old Otherpower Board

Login

Make a new account

Username:

Password:

Total Views

141 Scoop users have viewed this posting.

Related Links

· Also by electrak

You must be a registered user to post here. It's easy and free, and the link is on the upper right side of your page.
All trademarks and copyrights on this page are owned by their respective companies. Postings are owned by the poster, but may be deleted or moved at the ADMIN's sole discretion. The Rest © 2003 Forcefield.
You can Email the board ADMIN here. PLEASE include the username you signed up with!