Re: Charging telemetry data--take 1 (previous experience with old AGMs)

["Joe Smalley" <joes@worldfront.com>]

I would not write off the batteries until you test them individually.

I have three sets of "old AGM batteries" that are takeouts from other
people's cars.

First example:

Eight Dynasty UPS12-475 (date code HKB14640659) drag raced by Rich Rudman in
'97. He believes they were new in '96. I drag raced them in '98. We both
changed to Optimas and the batteries sat in the garage. They got charged
about every 18 months until this month. I pulled them out and did a pair of
equalize cycles on them and did a 25 amp Reserve Capacity test on them.

According to the Dynasty website, the original capacity was 23.4 amps for 5
hours for a capacity of 117 Ahr.

Results:
2 above 110 Ahr.
4 between 100 and 110 Ahr.
1 at 89 Ahr (second pair of equalization cycles brought it up to 112 Ahr)
1 at 28 Ahr (second pair of equalization cycles in progress but improved to
48 Ahr on first of the second pair)

Second example:

I got 26 Hawker Genesis G12V38Ah10EP from Rich Brown. Production date
appears to be 6124 (124th day of 1996 I believe) on all of them I examined.
The web site lists a 42 Ahr version of the battery to be 90 minutes at 23.5
amps for a rating of 35.2 Ahr. These sat over two years before I equalized
and tested them.

The results:
2 made over 30 Ahr.
4 were over 20 but under 30 (need another couple equalize cycles)
14 were over 10 but under 20 (need another couple equalize cycles)
5 had zero capacity (blown intercell connector or dried out)
1 had a hole burned in the top from the inside.

Third example:

I got ten Concorde Chairman 12-105 (date code 04-97) from EVs Northwest.
These are rated for 195 minutes at 25 amps for a rating of 81 Ahr. Three of
them were open when I got them and were promptly recycled. The rest tested
at 38 to 45 AHR. Two years ago my flooded house batteries failed in my
motorhome failed and I put three of these in their place. I used it all
summer and them in over the winter with the clicky charger plugged in all
the time. I expected them to be history by spring of last year. I pulled
them out and tested them. The capacity had risen to 75 to 78 AHR for the
three in the motorhome and the ones not in the motorhome had dropped to 33
to 35 Ahr. I put three different batteries in the motorhome over last winter
and left the charger on all winter. One battery got dropped and broke the
case. It got recycled this year. I tested the remaining six this spring and
five of the batteries are in the 75 to 78 Ahr range but one is about 30 Ahr
(the one that was never put in the motorhome). I would guess I ought to put
it in the motorhome next winter.

Summary:

These are three sets of "take out" AGM batteries that are over 5 years old
and still have respectable capacity. I have never had flooded batteries last
this long with this much abuse and neglect.

Don't write off the pack unless you test them. In my examples 87%, 7% and
50% of the batteries of each of these sets is making over 90% of their
original capacity.

If you are in a hurry and don't want to test them, give the batteries to
someone who has the time to test them but cannot afford to buy a new pack.
They will learn something and you might get another EV on the road that
might not do it without your generosity.

Joe Smalley
Rural Kitsap County WA
Fiesta 48 volts
NEDRA 48 volt street conversion record holder
joes@worldfront.com



----- Original Message -----
From: "Christopher Zach" <czach@computer.org>
To: <ev@listproc.sjsu.edu>
Sent: Friday, June 28, 2002 8:24 PM
Subject: Re: Charging telemetry data--take 1



> As for the date, I haven't dropped the pack yet. However I am willing to
> guess that they are the ones that came with the car, and are thus 1994
> vintage (ie: *old*).
>
> The verdict might just be that the pack is a hopeless little basket case.
> Still, 30 miles of range is enough to meet the orig objectives (drive to
> parent's house with the kids, 22 mile trip). I might just want to consider
> this to be my "training pack" and concentrate on babying it as I learn to
> drive an EV. Then in the fall I can drop the pack and replace it with a
> shiny new something (with knowledge about what makes a "good" pack and how
> to drive it).
>
> Any other comments are totally welcome and appreciated.
> Chris