Gel-Cell Battery repair?
 

I got a couple of rather large gel-cell batteries the other day (the
largest is a 12V 24ah) but it turns out they weren't such a great find.
Neither will take a charge; with the charger connected, neither battery will
draw so much as a single milliamp. Both batteries have a number of little
round covers; underneath the covers are small rubber caps covering a hole. I
noted that when I removed one of the rubber caps, there was a small inrush
of air as if there was a vacuum inside. My guess is that both batteries have
"dried up", possibly from lack of use. Is it as simple as adding water, and
if so, exactly how much and what kind (distilled, tap, etc) should be used?
Thanks for any advice.

In article ,
Chris F. wrote:
I got a couple of rather large gel-cell batteries the other day (the
largest is a 12V 24ah)

That's not large;-) We use 100 Ah types for powering location broadcasting
units. And that limit is purely through the weight for carrying.

but it turns out they weren't such a great find. Neither will take a
charge; with the charger connected, neither battery will draw so much as
a single milliamp. Both batteries have a number of little round covers;
underneath the covers are small rubber caps covering a hole. I noted
that when I removed one of the rubber caps, there was a small inrush of
air as if there was a vacuum inside. My guess is that both batteries
have "dried up", possibly from lack of use. Is it as simple as adding
water, and if so, exactly how much and what kind (distilled, tap, etc)
should be used?

IMHO, when any type of lead acid is dead, it's dead. If they've been left
discharged for any length of time for whatever reason they can't be sorted.

--
*I'm planning to be spontaneous tomorrow *

Dave Plowman London SW
To e-mail, change noise into sound.

Gell cells are not servicable. They must be replaced when they go
defective. You are supposed to have the old ones properly disposed of.


Jerry G.
======

"Jerry G." wrote in message
oups.com...
Gell cells are not servicable. They must be replaced when they go
defective. You are supposed to have the old ones properly disposed of.


Jerry G.
======
So what's with the little covered panels on top? I thought maybe it was a
place to add water.....

Hello, Chris!
You wrote on Sun, 14 Aug 2005 22:33:19 GMT:


CF "Jerry G." wrote in message
CF oups.com...
?? Gell cells are not servicable. They must be replaced when they go
?? defective. You are supposed to have the old ones properly disposed of.
??
?? Jerry G.
?? ======
CF So what's with the little covered panels on top? I thought maybe it was
CF a place to add water.....

Nope, they are there to provide a safety vent in case of a fault developing
that might otherwise cause a bang.


With best regards, 3T39. E-mail:

"Jerry G." wrote in message
oups.com...
Gell cells are not servicable. They must be replaced when they go
defective. You are supposed to have the old ones properly disposed of.




That's easy enough, anywhere that sells car batteries will take just about
any sort of dead lead acid batteries for disposal. I take them down to the
local Schucks autoparts.

Is there any way to "revive" them by applying higher charge voltage or
something?

"Chris F." wrote in message
...
I got a couple of rather large gel-cell batteries the other day (the
largest is a 12V 24ah) but it turns out they weren't such a great find.
Neither will take a charge; with the charger connected, neither battery
will
draw so much as a single milliamp. Both batteries have a number of little
round covers; underneath the covers are small rubber caps covering a hole.
I
noted that when I removed one of the rubber caps, there was a small inrush
of air as if there was a vacuum inside. My guess is that both batteries
have
"dried up", possibly from lack of use. Is it as simple as adding water,
and
if so, exactly how much and what kind (distilled, tap, etc) should be
used?
Thanks for any advice.

In article ,
Chris F. wrote:
Is there any way to "revive" them by applying higher charge voltage or
something?

No.

--
*If love is blind, why is lingerie so popular?

Dave Plowman London SW
To e-mail, change noise into sound.

I found a website that had plans for a "desulfator" that claims to be able
to revive at least a small percentage of such dead batteries. These
batteries probably failed from sulfation, as they were hardly used and kept
in storage for years. I'll give it a try sometime.

"Chris F." wrote in message
...
Is there any way to "revive" them by applying higher charge voltage or
something?

"Chris F." wrote in message
...
I got a couple of rather large gel-cell batteries the other day (the
largest is a 12V 24ah) but it turns out they weren't such a great find.
Neither will take a charge; with the charger connected, neither battery
will
draw so much as a single milliamp. Both batteries have a number of
little
round covers; underneath the covers are small rubber caps covering a
hole.
I
noted that when I removed one of the rubber caps, there was a small
inrush
of air as if there was a vacuum inside. My guess is that both batteries
have
"dried up", possibly from lack of use. Is it as simple as adding water,
and
if so, exactly how much and what kind (distilled, tap, etc) should be
used?
Thanks for any advice.

On Mon, 15 Aug 2005 22:37:30 GMT "Chris F."
wrote:

I found a website that had plans for a "desulfator" that claims to be able
to revive at least a small percentage of such dead batteries. These
batteries probably failed from sulfation, as they were hardly used and kept
in storage for years. I'll give it a try sometime.

Sulfation can be cured by long slow trickle charging, but cells which
have actually dried out can only be fixed by adding water. In most gel
cells and starved lead acid cells this is difficult, if not
impossible.

Unfortunately, the onex I had were dried out, and even after cutting
one of them open, I couldn't figure out any reasonable way to get
water in there without destroying them.

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------

This may mean something, maybe not. I lifted off one of the rubber caps, and
tried poking a small rod down through. There seemed to be a hard film on
top, but underneath the gel appeared to be at least moderately wet. I'm
guessing that perhaps poking a hole in the hard film, then adding water,
might just work.

"Jim Adney" wrote in message
...
On Mon, 15 Aug 2005 22:37:30 GMT "Chris F."
wrote:

I found a website that had plans for a "desulfator" that claims to be
able
to revive at least a small percentage of such dead batteries. These
batteries probably failed from sulfation, as they were hardly used and
kept
in storage for years. I'll give it a try sometime.

Sulfation can be cured by long slow trickle charging, but cells which
have actually dried out can only be fixed by adding water. In most gel
cells and starved lead acid cells this is difficult, if not
impossible.

Unfortunately, the onex I had were dried out, and even after cutting
one of them open, I couldn't figure out any reasonable way to get
water in there without destroying them.

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------

"Chris F." wrote in message
...
This may mean something, maybe not. I lifted off one of the rubber caps,
and
tried poking a small rod down through. There seemed to be a hard film on
top, but underneath the gel appeared to be at least moderately wet. I'm
guessing that perhaps poking a hole in the hard film, then adding water,
might just work.



Not if they're sulfated. I suppose you've got nothing to lose by trying but
I've never had any luck getting truly dead lead acid batteries of any type
to take a charge. Sometimes if you hit them with a higher voltage they'll
charge a bit, but they never last long.

On Tue, 16 Aug 2005 14:20:10 GMT "Chris F."
wrote:

This may mean something, maybe not. I lifted off one of the rubber caps, and
tried poking a small rod down through. There seemed to be a hard film on
top, but underneath the gel appeared to be at least moderately wet. I'm
guessing that perhaps poking a hole in the hard film, then adding water,
might just work.

There's no harm in trying, and it might actually work. The problem is
that you really don't know how far in the elecrolyte gel is. If you
can actually get the water to it, you're all set. In the Gates Cyclon
cells I took apart, there was a similar cap, but going down that hole
only got me half way to the active part of the cell.

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------

Here's some interesting plans for a battery desulfator:
http://www.shaka.com/~kalepa/desulf.htm
People claim to have good luck with it, so I might give it a try. Cheaper
than buying new gel-cells, that's for sure.

"Jim Adney" wrote in message
...
On Tue, 16 Aug 2005 14:20:10 GMT "Chris F."
wrote:

This may mean something, maybe not. I lifted off one of the rubber caps,
and
tried poking a small rod down through. There seemed to be a hard film on
top, but underneath the gel appeared to be at least moderately wet. I'm
guessing that perhaps poking a hole in the hard film, then adding water,
might just work.

There's no harm in trying, and it might actually work. The problem is
that you really don't know how far in the elecrolyte gel is. If you
can actually get the water to it, you're all set. In the Gates Cyclon
cells I took apart, there was a similar cap, but going down that hole
only got me half way to the active part of the cell.

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------