Anyone got any ideas about rejuvenating some AA NiMH batteries?

All these are being rejected by my charger as faulty, measuring them with
multimeter, some are reading 0.00 volts, some reading between 1.2 and 1.3
volts, but these will power a torch for only a very short time before the
bulb fades away to nothing.

Jake wrote:
Anyone got any ideas about rejuvenating some AA NiMH batteries?

All these are being rejected by my charger as faulty, measuring them with
multimeter, some are reading 0.00 volts, some reading between 1.2 and 1.3
volts, but these will power a torch for only a very short time before the
bulb fades away to nothing.


I've never found one. Some say a massive pulse of current will sort
them out, but IME once they are dead they are dead so to speak.


--
To people who know nothing, anything is possible.
To people who know too much, it is a sad fact
that they know how little is really possible -
and how hard it is to achieve it.

On Sat, 09 Jun 2012 16:00:53 +0100, The Natural Philosopher
wrote:

Jake wrote:
Anyone got any ideas about rejuvenating some AA NiMH batteries?

All these are being rejected by my charger as faulty, measuring them with
multimeter, some are reading 0.00 volts, some reading between 1.2 and 1.3
volts, but these will power a torch for only a very short time before the
bulb fades away to nothing.


I've never found one. Some say a massive pulse of current will sort
them out, but IME once they are dead they are dead so to speak.

I'm afraid I cannot really help with NiMH batteries, but Nicads used
to have a variety of approaches to recondition them.

Try uk.radio.amateur, the number of batteries turning up at radio
rallies and junk sales used to make electrochemical experts of us all.

HN

The do not seem to respond to the nicad fixing ideas of big current pulses
or freezing for long periods. One supposes that the internal shorts have
done more damage or are unshiftable.

Brian

--
Brian Gaff....Note, this account does not accept Bcc: email.
graphics are great, but the blind can't hear them
Email:
__________________________________________________ __________________________________________________ __________


"H. Neary" wrote in message
...
On Sat, 09 Jun 2012 16:00:53 +0100, The Natural Philosopher
wrote:

Jake wrote:
Anyone got any ideas about rejuvenating some AA NiMH batteries?

All these are being rejected by my charger as faulty, measuring them
with
multimeter, some are reading 0.00 volts, some reading between 1.2 and
1.3
volts, but these will power a torch for only a very short time before
the
bulb fades away to nothing.


I've never found one. Some say a massive pulse of current will sort
them out, but IME once they are dead they are dead so to speak.

I'm afraid I cannot really help with NiMH batteries, but Nicads used
to have a variety of approaches to recondition them.

Try uk.radio.amateur, the number of batteries turning up at radio
rallies and junk sales used to make electrochemical experts of us all.

HN

Jake wrote:
Anyone got any ideas about rejuvenating some AA NiMH batteries?

All these are being rejected by my charger as faulty, measuring them
with multimeter, some are reading 0.00 volts, some reading between
1.2 and 1.3 volts, but these will power a torch for only a very short
time before the bulb fades away to nothing.

I had nothing but trouble with various brands of these - duracell, energizer
and a german make eismann or similar, the crappy charger didn't seem to put
anything in them, and I tried a few different chargers.
I then started charging them 8 at a time in a 12 volt handset that has a
recharging socket.
Blasting 12v through them sorted the *******s out, although they get hot
(not warm - hot!) after about an hour, but then they work all week in things
like radios, torches cameras etc

"Phil L" wrote in message
...
Jake wrote:
Anyone got any ideas about rejuvenating some AA NiMH batteries?

All these are being rejected by my charger as faulty, measuring them
with multimeter, some are reading 0.00 volts, some reading between
1.2 and 1.3 volts, but these will power a torch for only a very short
time before the bulb fades away to nothing.

I had nothing but trouble with various brands of these - duracell,
energizer and a german make eismann or similar, the crappy charger didn't
seem to put anything in them, and I tried a few different chargers.
I then started charging them 8 at a time in a 12 volt handset that has a
recharging socket.
Blasting 12v through them sorted the *******s out, although they get hot
(not warm - hot!) after about an hour, but then they work all week in
things like radios, torches cameras etc

How did you attach the 8 batteries to the 12v charger?

Jake has brought this to us :
"Phil L" wrote in message
...
Jake wrote:
Anyone got any ideas about rejuvenating some AA NiMH batteries?

All these are being rejected by my charger as faulty, measuring them
with multimeter, some are reading 0.00 volts, some reading between
1.2 and 1.3 volts, but these will power a torch for only a very short
time before the bulb fades away to nothing.

I had nothing but trouble with various brands of these - duracell,
energizer and a german make eismann or similar, the crappy charger didn't
seem to put anything in them, and I tried a few different chargers.
I then started charging them 8 at a time in a 12 volt handset that has a
recharging socket.
Blasting 12v through them sorted the *******s out, although they get hot
(not warm - hot!) after about an hour, but then they work all week in
things like radios, torches cameras etc

How did you attach the 8 batteries to the 12v charger?

You can buy 8 in a pack AA cell holders, which has them in series, then
just connect across the 12v.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

"Harry Bloomfield" wrote in message
. uk...
Jake has brought this to us :
"Phil L" wrote in message
...
Jake wrote:
Anyone got any ideas about rejuvenating some AA NiMH batteries?

All these are being rejected by my charger as faulty, measuring them
with multimeter, some are reading 0.00 volts, some reading between
1.2 and 1.3 volts, but these will power a torch for only a very short
time before the bulb fades away to nothing.

I had nothing but trouble with various brands of these - duracell,
energizer and a german make eismann or similar, the crappy charger
didn't seem to put anything in them, and I tried a few different
chargers.
I then started charging them 8 at a time in a 12 volt handset that has a
recharging socket.
Blasting 12v through them sorted the *******s out, although they get hot
(not warm - hot!) after about an hour, but then they work all week in
things like radios, torches cameras etc

How did you attach the 8 batteries to the 12v charger?

You can buy 8 in a pack AA cell holders, which has them in series, then
just connect across the 12v.

I mean polarity wise. Do you match +/+ or +/-?

Jake wrote :
"Harry Bloomfield" wrote in message
. uk...
Jake has brought this to us :
"Phil L" wrote in message
...
Jake wrote:
Anyone got any ideas about rejuvenating some AA NiMH batteries?

All these are being rejected by my charger as faulty, measuring them
with multimeter, some are reading 0.00 volts, some reading between
1.2 and 1.3 volts, but these will power a torch for only a very short
time before the bulb fades away to nothing.

I had nothing but trouble with various brands of these - duracell,
energizer and a german make eismann or similar, the crappy charger didn't
seem to put anything in them, and I tried a few different chargers.
I then started charging them 8 at a time in a 12 volt handset that has a
recharging socket.
Blasting 12v through them sorted the *******s out, although they get hot
(not warm - hot!) after about an hour, but then they work all week in
things like radios, torches cameras etc

How did you attach the 8 batteries to the 12v charger?

You can buy 8 in a pack AA cell holders, which has them in series, then
just connect across the 12v.

I mean polarity wise. Do you match +/+ or +/-?

To charge them, +ve of charger to +ve of batteries.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

Jake wrote

Anyone got any ideas about rejuvenating some AA NiMH batteries?

Just replace them. Not worth farting around with them so cheap now.

All these are being rejected by my charger as faulty, measuring them with
multimeter, some are reading 0.00 volts, some reading between 1.2 and 1.3
volts, but these will power a torch for only a very short time before the
bulb fades away to nothing.

On 09/06/2012 15:48, Jake wrote:
Anyone got any ideas about rejuvenating some AA NiMH batteries?

All these are being rejected by my charger as faulty, measuring them with
multimeter, some are reading 0.00 volts, some reading between 1.2 and 1.3
volts, but these will power a torch for only a very short time before the
bulb fades away to nothing.

The ones reading 0 are likely stone dead. Anything above a volt is
probably recoverable but how much charge it will hold is anybodies
guess. You want to try them in a dumb charger that will charge
individual cells at a modest rate and for a fixed time.

They probably are faulty so watch out for signs of electrolyte leakage
overheating and in extremis fire! ie don't put them on charge for 10-14
hours and forget about them or you may be in for a nasty surprise!

--
Regards,
Martin Brown

On Jun 9, 3:48*pm, "Jake" wrote:
Anyone got any ideas about rejuvenating some AA NiMH batteries?

All these are being rejected by my charger as faulty, measuring them with
multimeter, some are reading 0.00 volts, some reading between 1.2 and 1.3
volts, but these will power a torch for only a very short time before the
bulb fades away to nothing.

If they're reading zero volts they could be fine but being falsely
rejected by a typical zombie "intelligent" charger. Trickle charge
them on an old-fashioned bog standard charger until the volts go to
1.3-ish then a fast charger will accept them (or possibly not).

rusty

On Sat, 9 Jun 2012 15:48:39 +0100, "Jake"
wrote:

Anyone got any ideas about rejuvenating some AA NiMH batteries?

All these are being rejected by my charger as faulty, measuring them with
multimeter, some are reading 0.00 volts, some reading between 1.2 and 1.3
volts, but these will power a torch for only a very short time before the
bulb fades away to nothing.

Sling them in the recycle bin along with most / all of your other
rechargeables. Then buy some Sanyo Eneloops and realise that all the
hours and money spent on lesser rechargeables and rejuvenating etc
simply isn't worth the effort.

(no connection etc except as a very satisfied customer)


--