Old Virgin Deka AGMs - mixing with newer stock?

[elektro 159]

I found a stash of old Deka AGMs that are in "virgin" condition, never been
charged/discharged or even wired up. However, they've been on the shelf for
2.5 years. They're open voltage is running about 12.25v which is roughly 50%
capacity (according to Deka's technical info).I unfortunately don't have
access to an impedance meter or battery checker, however being Deka AGMs I'd
figure they're in at least recoverable condition. They are available at
discount, so they're worth the buy if they're recoverable.

My question is two fold:

1) Is it possible to recover them? If so, what would be the process to
recover them?

2)Can I mix fresh, new Dekas with these older, "virgin" Dekas? Assuming
they're recoverable, is there a way to bring them back to a servicable state
as new ones? My EV pack is series-wired and has a good BMS system on it.
Assuming the older "virgin" Dekas are recovered and brought to a similar
capacity as the new ones, would the BMS be able to make them workable?

Most of the time I'd only be discharging my EV pack to %80 State of Charge
before charging anyways, with the occasional run down to %50 or maybe %30.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.sjsu.edu/mailman/private/ev/attachments/20090705/3a0c9d20/attachment.html 
_______________________________________________
General EVDL support: http://evdl.org/help/
Usage guidelines: http://evdl.org/help/index.html#conv
Archives: http://evdl.org/archive/
Subscription options: http://lists.sjsu.edu/mailman/listinfo/ev

[EVDL Administrator]

On 5 Jul 2009 at 13:08, elektro 159 wrote:

> I found a stash of old Deka AGMs that are in "virgin" condition, never
> been charged/discharged or even wired up. However, they've been on the
> shelf for 2.5 years.

They sound like they'd make pretty good ballast.  ;-)

Seriously, that's a fairly long time for a lead battery to sit unwanted and
unloved.  Most AGMs and many gels have low self discharge and can sit for
quite a while without a maintenance charge.  But they really need a little
bit of 'lectric lovin' every 6-12 months or so, or they'll develop sulfation
from neglect.

The blinky-LED electronic gadgets won't fix this.  You may see them recover
some capacity with repeated cycling, and you might luck out -- but dollars
to doughnuts they won't come up to the nominal 80% of their original specs.

FWIW, I have some older Hawker Genesis AGMs that I forgot about in a corner
of the cellar, and let sit for maybe 3-4 years.  When I went back to them I
beat on 'em for a couple of weeks, cranking up the power supply with a
taillight bulb in series, then switching to a shop charger. I eventually got
them to take a bit of a charge, but they could only hold a few amp-hours,
maybe 10-20% of their rated capacity.  So now I use 'em for ballast in my
Elec-Trak's weight box for winter snow plowing.

If you're that interested, I'd suggest buying one or two of these pigs-in-a-
poke.  Cycle them and see what capacity you can get out of them, whether
it's enough to do you any good.  If that's not an option -- it's all or
nothing, now or never -- I probably wouldn't pay much more than scrap lead
value for them.  But that's me.

As for mixing them, your battery's capacity is normally set by its lowest-
capacity module, which will almost surely be one of the old guys.  When it's
flat, you're done.  Time for the plug -- or the tow hook.

With a really aggressive BMS such as Lee Hart's balancer, you can prop up
the feebs and get a little more apparent capacity from the pack, but they'd
have to be really cheap to make it worthwhile, IMO.

Good luck!

David Roden
EVDL Administrator
http://www.evdl.org/


_______________________________________________
General EVDL support: http://evdl.org/help/
Usage guidelines: http://evdl.org/help/index.html#conv
Archives: http://evdl.org/archive/
Subscription options: http://lists.sjsu.edu/mailman/listinfo/ev

[Lee Hart]

elektro 159 wrote:
> > I found a stash of old Deka AGMs that are in
> > "virgin" condition, never been charged/discharged or even wired up.
> > However, they've been on the shelf for 2.5 years.

EVDL Administrator wrote:
>  They sound like they'd make pretty good ballast.  ;-)
>  Seriously, that's a fairly long time for a lead battery to sit
>  unwanted and unloved.  Most AGMs and many gels have low self
>  discharge and can sit for quite a while without a maintenance charge.
>  But they really need a little bit of 'lectric lovin' every 6-12
>  months or so, or they'll develop sulfation from neglect.

One encouraging sign was that Elecktro said they measured 12.5v or so.
That says there is still hope. If they had been below 12.0v, I'd agree
with David -- they would most likely be door stops.
--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net

_______________________________________________
General EVDL support: http://evdl.org/help/
Usage guidelines: http://evdl.org/help/index.html#conv
Archives: http://evdl.org/archive/
Subscription options: http://lists.sjsu.edu/mailman/listinfo/ev

[damon henry]

I got some UPS batteries from the facility guys at work one time that were the same type of deal.  They had been on the shelf for 2 years still in their box.  I got a decent amount of use out of them on my motorcycle.  I still use a couple around the garage for things.  They never performed like brand new, and they did not have great cycle life for an EV.  In my case it was just 4 of them, and I used them all together, so they were all in about the same shape, but they were a pretty good deal for free, and got me through at least one riding season.

damon

> Date: Mon, 6 Jul 2009 10:23:24 -0500
> From: [hidden email]
> To: [hidden email]
> Subject: Re: [EVDL] Old Virgin Deka AGMs - mixing with newer stock?
>
> elektro 159 wrote:
> > > I found a stash of old Deka AGMs that are in
> > > "virgin" condition, never been charged/discharged or even wired up.
> > > However, they've been on the shelf for 2.5 years.
>
> EVDL Administrator wrote:
> >  They sound like they'd make pretty good ballast.  ;-)
> >  Seriously, that's a fairly long time for a lead battery to sit
> >  unwanted and unloved.  Most AGMs and many gels have low self
> >  discharge and can sit for quite a while without a maintenance charge.
> >  But they really need a little bit of 'lectric lovin' every 6-12
> >  months or so, or they'll develop sulfation from neglect.
>
> One encouraging sign was that Elecktro said they measured 12.5v or so.
> That says there is still hope. If they had been below 12.0v, I'd agree
> with David -- they would most likely be door stops.
> --
> Ring the bells that still can ring
> Forget the perfect offering
> There is a crack in everything
> That's how the light gets in -- Leonard Cohen
> --
> Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
>
> _______________________________________________
> General EVDL support: http://evdl.org/help/
> Usage guidelines: http://evdl.org/help/index.html#conv
> Archives: http://evdl.org/archive/
> Subscription options: http://lists.sjsu.edu/mailman/listinfo/ev
>

_________________________________________________________________
Hotmail® has ever-growing storage! Don’t worry about storage limits.
http://windowslive.com/Tutorial/Hotmail/Storage?ocid=TXT_TAGLM_WL_HM_Tutorial_Storage_062009
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.sjsu.edu/mailman/private/ev/attachments/20090706/014fdd19/attachment.html 
_______________________________________________
General EVDL support: http://evdl.org/help/
Usage guidelines: http://evdl.org/help/index.html#conv
Archives: http://evdl.org/archive/
Subscription options: http://lists.sjsu.edu/mailman/listinfo/ev