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Gear / Technical Help => Remote Power => Topic started by: dlh on May 08, 2011, 05:29:08 PM

Title: Building Nimh 12v battery pack
Post by: dlh on May 08, 2011, 05:29:08 PM
I have a bunch of AA Nimh batteries.  I'm planning to connect two 8-cell battery holders in parallel to get a longer running 12v pack.
Just thought I'd check in here to be sure there's nothing wrong with that.  That should be versatile enough to power my 9-12v devices.
I'm hoping to power a new DR-680 with that arrangement.  I understand that some folks have been successful with a single 9v Wally World battery on the 680 too, yes?

I'm pretty sure that some here run two Wally World Li Ion packs in parallel for longer run time.
Just checking to be sure.

Thanks,
Dave
Title: Re: Building Nimh 12v battery pack
Post by: F.O.Bean on May 08, 2011, 07:52:55 PM
Before you do anything, order this charger:

http://www.thomasdistributing.com/Maha-Powerex-MH-C9000-AA--AAA-Battery-Chargerbr_p_134.html?frontpage=1

or this:

http://www.cyberguys.com/product-details/?productid=34279
Title: Re: Building Nimh 12v battery pack
Post by: dlh on May 08, 2011, 08:23:02 PM
Before you do anything, order this charger:

http://www.thomasdistributing.com/Maha-Powerex-MH-C9000-AA--AAA-Battery-Chargerbr_p_134.html?frontpage=1

or this:

http://www.cyberguys.com/product-details/?productid=34279
I have a couple of chargers now, this one the newest:
http://www.mahaenergy.com/store/viewItem.asp?idProduct=422
Title: Re: Building Nimh 12v battery pack
Post by: F.O.Bean on May 08, 2011, 08:26:22 PM
Before you do anything, order this charger:

http://www.thomasdistributing.com/Maha-Powerex-MH-C9000-AA--AAA-Battery-Chargerbr_p_134.html?frontpage=1

or this:

http://www.cyberguys.com/product-details/?productid=34279
I have a couple of chargers now, this one the newest:
http://www.mahaenergy.com/store/viewItem.asp?idProduct=422

Sweet, that's a nice charger too :)
Title: Re: Building Nimh 12v battery pack
Post by: it-goes-to-eleven on May 11, 2011, 04:38:39 PM
If you are going to make a pack, you should use new cells, all from the same source.  Otherwise each cell will tend to have different performance, etc.
Title: Re: Building Nimh 12v battery pack
Post by: F.O.Bean on May 11, 2011, 04:58:13 PM
If you are going to make a pack, you should use new cells, all from the same source.  Otherwise each cell will tend to have different performance, etc.


100% agreed
Title: Re: Building Nimh 12v battery pack
Post by: dlh on May 12, 2011, 07:50:18 AM
Well, the prototype case is made (from 2 RS 8cell holders).  Made it from a small fishing utility box.
I have one set of 16 Duracells (all same age); getting a set of Imedions to try.
I wonder, if one set of 8 is 2400 ma and the other is 2650 ma, I guess performance is limited by the "weakest link", or the 2400's would die first leaving the 2650 handling the full load.
Just thinking.

Just got my DR-680  :D and am beginning to do runtime tests.
I'm curious to compare runtimes of the 16 AA's vs a Ultralast LiIon. I'm trying Transcend 32gb class 10 cards; I know a few have had problems; we'll see.
I think (hope) the 680 uses the external 12v source first and then switches to internals; that would allow me to hot-swap external supplies.
What would happen if the 12v external was swapped with a 9v LI?  Would the 680 feed off of the internals until spent and then switch to the 9v.  That's the way my PMD671 seems to behave.

Interested in opinions on the Imedions; I know some here have used them.
(Now to the basement to make chopped cables.)

Thanks
Dave
Title: Re: Building Nimh 12v battery pack (completed-tested-with pics)
Post by: dlh on May 17, 2011, 02:47:44 PM
Found a better case;one of my unused fly boxes that was stripped of foam.  This uses 16 AA's for 12v.  (Yes, I have Li-ion too.)
I installed a jack in the back which is the same size as the Ultralast Li-ions so cables are interchangeable.
First run-time test with Duracells was about 8 hrs. with 6 channels p48.
Second test was with Powerex's, 6 channels p48 and was about 9 hours.
Didn't think I'd get that much.
Title: Re: Building Nimh 12v battery pack
Post by: F.O.Bean on May 17, 2011, 05:26:15 PM
NICE Bro ;D
Title: Re: Building Nimh 12v battery pack
Post by: odmen01 on May 17, 2011, 05:34:58 PM
I tried building a similar one..................but  :-\ :-\ :-\