[TechAssist] Re: Any way to revitalize dead sealed lead acid batteries?
- From: "Jerome Silverman" <greentron@xxxxxxx>
- To: <techassist@xxxxxxxxxxxxx>
- Date: Sat, 28 Aug 2004 20:52:48 -0400
Probably garbage, but you can try keeping them on charge for a long time and
there might be some recovery. If there is any recovery you can only tell by
seeing how long they will run a load. When a lead acid battery discharges,
lead sulfate crystals form over the active area. When you recharge it the
crystals go back into solution. If the crystals are allowed to exist for a
long time, they merge into one another and become less soluble, blocking off
the active area. They will still dissolve but it can take a really long
time. Thats why the instructions with the battery say to recharge after any
use within 48 hours or the battery may have reduced capacity.
A good quality sealed lead acid battery is supposed to retain at least 90%
of its charge after one year of storage. There are a lot of poor quality
batteries around and they self discharge quickly, so they are already
sulfated by the time you get them and they either wont take a charge or they
run down quickly in use. We used to stock and sell batteries for portable
vcrs and camcorders but more and more of the batteries were returned as
defective. We started testing them as we received them and sending back the
bad and weak ones. On some shipments we had to send back the whole thing.
When K-Mart and WalMart started to sell them we gave up. Their
over-the-counter every day price was usually less than our wholesale cost. I
remember once when we were Thomson ASC and they ran out of GB90 batteries
which were failing like mad under warranty and they said that they didnt
know when they would get more. I told them that I saw plenty at WalMart and
they authorized me to buy them for the warranties. WalMart price was $39.95
and the Thompson distributor dealer price was $42.
Jerry Silverman
Greentron Inc
4 Newland Ave Greenville SC 29609
Fax/Phone 864 232 3889
greentron@xxxxxxx
----- Original Message -----
From: "Gary McCartney" <gary@xxxxxxxxxxx>
To: <techassist@xxxxxxxxxxxxx>
Sent: Saturday, August 28, 2004 6:14 PM
Subject: [TechAssist] Any way to revitalize dead sealed lead acid batteries?
> I found a box of 10 brand new sealed lead acid batteries, 12V 4AH that I
> forgot I had. Problem is, they are all very low or dead. I tried
> connecting my power supply with current limiting but the batteries
> aren't drawing any current at all.
>
> Is there any way to kick these into charging up, or are they garbage?
> --
>
>
>
>
> Gary McCartney
>
> McCartney Electronics
> Guelph Ontario Canada
> Est. 1984
> email: gary (at) number63.ca
>
>
>
>
>
>
>
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