A recent disscussion about having batteries rebuilt sparked my
attention and I copied and pasted an e-mail from WJ which May be of
interest.

A question about whether or not rechargeable batteries could be revived
or have their "memory" erased sparked a healthy discussion, and we
asked you to add your experiences to the fray. Here are some of your
responses. - Editor

"I've tried the freezer method of recharging several times. I've
never had it work for me." - Brian Walker

"I have used the freezer method many times for my battery-powered
drills, and it seems to work very well. Just remind everyone to make
sure the battery is completely up to room temperature before
recharging." - Earl

"I tried the method of placing a battery in the freezer for
approximately 12 hours, and then allow it to defrost fully before
re-charging, and it did accept a full charge. Thanks for the great
ideas." - Kevin Elswick

Clearly, there seems to be some disagreement as to whether freezing
works, but several folks wrote in to tell of some different methods.
- Editor

"In the Air Force, we would periodically pull the battery and
discharge each cell individually to a totally discharged state, then
recharge the battery as a whole. As a safety note, a NiCad cell can
generate upwards of 50 amps for a very short period of time if
shorted." - Rick Gibson

"Small shorts can appear inside a battery, causing recharge problems.
I have hooked the negative terminal of a 9.6-volt battery to the
negative terminal of a 12-volt car battery, and the positive terminal
to one end of an old metal file. Take a lead from the positive of the
9.6-volt battery and 'stroke' it down the file. The teeth on the
file cause the lead to make and break the connection to the car
battery, which clears the short in the 9.6-volt battery. You can then
place the battery back in the charger and fully charge it again. I have
used the method numerous times with good success." - Harvey Leckie

"I have revived NiCads by zapping them with an electrolytic capacitor
charged to about 12 volts or so, and zapping a single cell a few times
in both directions. It seems to give it extended life, depending on the
cell." - Ajmal Rahman

"I don't bother reviving batteries. I rebuild them. The cells inside
the packs may look like standard size AA or C cells, but the dimensions
are slightly different. However, an electronic components shop near me
sells these odd size NiCad and NiMh cells. A little care in
disassembling the case, some soldering and duct tape, and you have a
cheap new battery pack." - Anthony Kerstens

One of the more unusual responses directed us to a web site of a
company that sells what it claims is a "Battery Resurrection
Guide." Their web site describes it as "an online, password
secured, step by step guide that will enable anyone who can use a few
common tools to resurrect rechargeable Ni-Cad batteries to their full
potential so they will hold a charge. You will need access to
individual cells within the battery, therefore some disassembly will be
required for most power tool batteries." Here's what one reader
said about his experience with this company. - Editor

"My scam alert was on high, but I took a chance on the $12.95 and was
promptly e-mailed a manual describing the process of resurrection.
There are no special tools. Most required items can be found around any
household. The resurrection did not work on my DeWalt batteries, but it
has worked on several Craftsman batteries. As an extra benefit, my
knowledge of rechargeable batteries is greatly improved. I ended up
rebuilding the DeWalt batteries with higher quality battery cells and
saved more than the $12.95 investment." - Gary Powers

One final note for owners of Ryobi tools: Ryobi has recently cut its
battery price to $25 ($20 when bought in pairs) to make replacement
more enticing. For more on that, and on Ryobi, check out the Tool Maker
Insider section of this issue. - Editor

henry wrote:
A recent disscussion about having batteries rebuilt sparked my
attention and I copied and pasted an e-mail from WJ which May be of
interest.
snip article to save a few bits and bytes
Thanks

Inviato da X-Privat.Org - Registrazione gratuita http://www.x-privat.org/join.php

On the basis of the recently posted article on freezing batteries, I
tried the technique out on 3 Makita 9.6 volt batteries (one old black
stick type, and two modern red ones) I had been saving until I could
have them rebuilt with new cells.

I froze them for 16 hours, let them thaw for 24 hours and charged them.
Result: The stick battery and one of the two red ones have come back to
life. I don't know for how long but they seem to be OK. One red battery
is still as dead as a doornail.

Two out of three ain't bad. Thanks for the tip.

Cheers,

Larry

By Wed, 24 May 2006 16:41:53 +1200, Larry Spitz
decided to post
" BATTERIES Giving new life to them" to
rec.woodworking:

On the basis of the recently posted article on freezing batteries, I
tried the technique out on 3 Makita 9.6 volt batteries (one old black
stick type, and two modern red ones) I had been saving until I could
have them rebuilt with new cells.

I froze them for 16 hours, let them thaw for 24 hours and charged them.
Result: The stick battery and one of the two red ones have come back to
life. I don't know for how long but they seem to be OK. One red battery
is still as dead as a doornail.

Two out of three ain't bad. Thanks for the tip.

Cheers,

Larry

Whoa, sorry the article, or at least a link to it was snipped as I
missed it entirely. But, it seems that y'all are saying to freeze a
battery for a while and then defrost and charge it -- for a potential shot
at rejuvenating a dead one??

Sounds just low-effort enough that I'd give it a shot. Hey, I've seen it
work with various locked up parts, including hard disks.

/..


--

find / -iname "*gw*" -exec rm -rf {} \;

In heaven, there is no beer,
That's why we drink it here,
And when we're all gone from here,
Our friends will be drinking all the beer!
-- Famous old Czech song about beer --

henry wrote:
"In the Air Force, we would periodically pull the battery and
discharge each cell individually to a totally discharged state, then
recharge the battery as a whole. As a safety note, a NiCad cell can
generate upwards of 50 amps for a very short period of time if
shorted." - Rick Gibson

This technique is also used by model racers to get as much juice as
possible from the battery. Do it too much though, and you wear out the
battery faster.

Some information:

http://www.repairfaq.org/ELE/F_NiCd_Battery.html


Chris