Hello,

My cordless drill needs to be re celled. Can anyone recommend a good
supplier of sub c nicads?

Thanks,
Stephen.

In article ,
Stephen wrote:
Hello,

My cordless drill needs to be re celled. Can anyone recommend a good
supplier of sub c nicads?

Be careful of Ebay. Some junk on there.

If you find one, I'd like to know.

They are the sort of thing you need to buy by the thousand to get a good
price. I used to have a pro film camera (etc) battery fixer nearby, and
they'd sell me them at a good price as a favour. But sadly closed down now.

You might do as well to have them professionally fixed. At least you get a
warranty.

--
*Eschew obfuscation *

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

On 19/06/2015 11:48, Stephen wrote:
Hello,

My cordless drill needs to be re celled. Can anyone recommend a good
supplier of sub c nicads?

Thanks,
Stephen.

I was in the same position a while ago. I failed to find a supplier of
decent cells at a price that made sense so bought a new drill driver
with Li-Ion batteries instead - it's been an excellent buy. No more
finding that the batteries are flat when you need the drill, fast
charge, much more torque ... it was worth the cost.
Now I need the right tuit to re-cell the Ni-Cd batteries for the old
drillls with Li-Ion (with protection, before anyone shouts) cells. So
much to do and so little time!

wrote in message ...

On 19/06/2015 11:48, Stephen wrote:
Hello,

My cordless drill needs to be re celled. Can anyone recommend a good
supplier of sub c nicads?

Thanks,
Stephen.

I was in the same position a while ago. I failed to find a supplier of
decent cells at a price that made sense so bought a new drill driver with
Li-Ion batteries instead - it's been an excellent buy. No more finding that
the batteries are flat when you need the drill, fast charge, much more
torque ... it was worth the cost.
Now I need the right tuit to re-cell the Ni-Cd batteries for the old
drillls with Li-Ion (with protection, before anyone shouts) cells. So much
to do and so little time!


I re-celled some dewalt 18v packs about 18 months ago, and although
initially they were fine, after a few months their capacity was miniscule. I
ended up buying new ones from 168onlinegoods on ebay - they are guaranteed
one year and were so good I actually bought a second pair from the same
seller:

http://www.ebay.co.uk/itm/2-X-drill-...em20d585 d5e9

Andrew

/I re-celled some dewalt 18v packs about 18 months ago, and although
initially they were fine, after a few months their capacity was miniscule. I
ended up buying new ones from 168onlinegoods on ebay - they are guaranteed
one year and were so good I actually bought a second pair from the same .../q

I faced same prob a year or so back with Makita drills. I modified the drills to take new Makita lithium battery packs charged by the correct but ebayed Makita charger. Haven't looked back since.

Anyone want the old (containing sub C I believe) Makita 18v nicds to pick over? Yours for postage costs...

Jim K

In article ,
JimK writes:
/I re-celled some dewalt 18v packs about 18 months ago, and although
initially they were fine, after a few months their capacity was miniscule. I
ended up buying new ones from 168onlinegoods on ebay - they are guaranteed
one year and were so good I actually bought a second pair from the same .../q

I've recelled my excellent ~25 year old B&D screwdriver a few times.
That uses shorter C cells. About 6 months ago, I tried to locate a
supplier for someone else's drill, and a few suppliers told me they
can no longer get NiCd cells made - they still have stock of the
common sizes, but not the sub-C.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

I used some similar nickel metal hydride cells to redo an old mini vacuum
some years ago, though of course the charger was pretty basic, it worked
better than when it was new.Eventually the motor fell to bits though. Sulk.
Built to a price I think the phrase is.
Brian

--
From the Sofa of Brian Gaff Reply address is active
"Dave Plowman (News)" wrote in message
...
In article ,
Stephen wrote:
Hello,

My cordless drill needs to be re celled. Can anyone recommend a good
supplier of sub c nicads?

Be careful of Ebay. Some junk on there.

If you find one, I'd like to know.

They are the sort of thing you need to buy by the thousand to get a good
price. I used to have a pro film camera (etc) battery fixer nearby, and
they'd sell me them at a good price as a favour. But sadly closed down
now.

You might do as well to have them professionally fixed. At least you get a
warranty.

--
*Eschew obfuscation *

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

On Saturday, 20 June 2015 08:59:45 UTC+1, Brian-Gaff wrote:
I used some similar nickel metal hydride cells to redo an old mini vacuum
some years ago, though of course the charger was pretty basic, it worked
better than when it was new.Eventually the motor fell to bits though. Sulk.
Built to a price I think the phrase is.
Brian

this is why I like old tools


NT

On 20/06/15 08:13, Andrew Gabriel wrote:
In article ,
JimK writes:
/I re-celled some dewalt 18v packs about 18 months ago, and although
initially they were fine, after a few months their capacity was miniscule. I
ended up buying new ones from 168onlinegoods on ebay - they are guaranteed
one year and were so good I actually bought a second pair from the same .../q

I've recelled my excellent ~25 year old B&D screwdriver a few times.
That uses shorter C cells. About 6 months ago, I tried to locate a
supplier for someone else's drill, and a few suppliers told me they
can no longer get NiCd cells made - they still have stock of the
common sizes, but not the sub-C.


Why not use NiMH cells, they are have a higher capacity and are more
'robust'. Finding some sizes with tags these days with tags isn't always
easy, although CPC tend to be a good source.

Depending on how 'smart' the charger is, you may get away with just
increasing the charge time in proportion to the capacity.

I 're-celled' some radio battery packs for an amateur radio handheld and
they have lasted over a decade. The packs have an internal charge
circuit which I modified to increase the charge current to match the new
cells.

In another radio, I modified it to accept AA cells rather than sub C, as
the NiMH AAs are higher in capacity than the sub C NiCads. I also added
a constant current charger. Again, over a decade on, the NiMH cells are
still good.

In article ,
Brian Reay wrote:
In another radio, I modified it to accept AA cells rather than sub C, as
the NiMH AAs are higher in capacity than the sub C NiCads. I also added
a constant current charger. Again, over a decade on, the NiMH cells are
still good.

Radios tend to be a lot kinder on cells than power tools. And for decent
performance, the peak current available is important. I doubt any AA sized
NiMH can match a Sub-C for that.

--
Is the hardness of the butter proportional to the softness of the bread?*

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

Brian Reay wrote:
Why not use NiMH cells, they are have a higher capacity and are more
'robust'. Finding some sizes with tags these days with tags isn't always
easy, although CPC tend to be a good source.

One issue with 'power' NiMH is they have substantial self-discharge - it's
not unusual to go flat in a month. So you get out the power tool from the
cupboard thinking 'I'll just...' and it's flat - you need to wait to
recharge it. NiCd tend to retain charge better over long periods.

There are low self discharge NiMH, but I haven't seen them in industrial
sizes (beyond memory retention cells). Maybe they exist, I don't know.

Theo

On 20/06/2015 08:13, Andrew Gabriel wrote:
In article ,
JimK writes:
/I re-celled some dewalt 18v packs about 18 months ago, and although
initially they were fine, after a few months their capacity was miniscule. I
ended up buying new ones from 168onlinegoods on ebay - they are guaranteed
one year and were so good I actually bought a second pair from the same .../q

I've recelled my excellent ~25 year old B&D screwdriver a few times.
That uses shorter C cells. About 6 months ago, I tried to locate a
supplier for someone else's drill, and a few suppliers told me they
can no longer get NiCd cells made - they still have stock of the
common sizes, but not the sub-C.

I used these people about a year ago

http://www.batteriesplus.co.uk/acata...Batteries.html

they still seem to have quite a range of sizes available, and they do
bulk packs for 12, 14.4 or 18 V batteries which makes the cost slightly
more reasonable.

--
CB

On Sat, 20 Jun 2015 07:13:46 +0000 (UTC), Andrew Gabriel wrote:

About 6 months ago, I tried to locate a supplier for someone else's
drill, and a few suppliers told me they can no longer get NiCd cells
made - they still have stock of the common sizes, but not the sub-C.

yep, NiCd has more or less disappeared. NiHM is very similar but
without the major problems of NiCd, ie rapid self discharge and the
"memory effect".

I've recelled a couple of times an ancient but the best powered screw
driver I've ever used. 1st time was NiCds didn't last long, 2nd was
NiMH still going strong after a good few years.

--
Cheers
Dave.

On 20 Jun 2015 16:22:26 +0100 (BST), Theo Markettos wrote:

One issue with 'power' NiMH is they have substantial self-discharge -
it's not unusual to go flat in a month.

Against NiCd I've found the opposite.

So you get out the power tool from the cupboard thinking 'I'll just...'
and it's flat - you need to wait to recharge it.

NiCd based drill is in that mode ATM. With the self discharge period
about a week.

Recelled (Tagged, plain card sleeve, "industrial"), Sub-C NiCD based
screwdriver "just works", even when not used for a month or more.

--
Cheers
Dave.

On 21/06/15 10:42, Dave Liquorice wrote:
On Sat, 20 Jun 2015 07:13:46 +0000 (UTC), Andrew Gabriel wrote:

About 6 months ago, I tried to locate a supplier for someone else's
drill, and a few suppliers told me they can no longer get NiCd cells
made - they still have stock of the common sizes, but not the sub-C.

yep, NiCd has more or less disappeared. NiHM is very similar but
without the major problems of NiCd, ie rapid self discharge and the
"memory effect".

Actually NiMh is worse at self discharge than NiCd and is also more
damaged by being flattened.

NiCd disappeared because of cadmium, which is a metal that it is
politically incorrect to use, and because NiMh is a bit more energy dense.


I've recelled a couple of times an ancient but the best powered screw
driver I've ever used. 1st time was NiCds didn't last long, 2nd was
NiMH still going strong after a good few years.



--
New Socialism consists essentially in being seen to have your heart in
the right place whilst your head is in the clouds and your hand is in
someone else's pocket.

In article o.uk,
Dave Liquorice wrote:
On 20 Jun 2015 16:22:26 +0100 (BST), Theo Markettos wrote:

One issue with 'power' NiMH is they have substantial self-discharge -
it's not unusual to go flat in a month.

Against NiCd I've found the opposite.

Must admit to not having found a vast difference between the two. More
difference between different makes of the same type.

So you get out the power tool from the cupboard thinking 'I'll just...'
and it's flat - you need to wait to recharge it.

NiCd based drill is in that mode ATM. With the self discharge period
about a week.

Really, if something really is used only occasionally, cordless is an
extremely expensive 'convenience'. And actually a time waster if you have
to wait while the batteries charge.

Recelled (Tagged, plain card sleeve, "industrial"), Sub-C NiCD based
screwdriver "just works", even when not used for a month or more.

Trouble is it really is a gamble buying replacement cells - given how much
they influence the performance of most tools.

--
*We have enough youth, how about a fountain of Smart?

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

In article o.uk,
"Dave Liquorice" writes:
On Sat, 20 Jun 2015 07:13:46 +0000 (UTC), Andrew Gabriel wrote:

About 6 months ago, I tried to locate a supplier for someone else's
drill, and a few suppliers told me they can no longer get NiCd cells
made - they still have stock of the common sizes, but not the sub-C.

yep, NiCd has more or less disappeared. NiHM is very similar but
without the major problems of NiCd, ie rapid self discharge and the
"memory effect".

What about internal resistance? NiCd is very low, and I suspect
many power tools relied on that. Never measured NiMH.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On Fri, 19 Jun 2015 11:48:55 +0100, Stephen
wrote:

Hello,

My cordless drill needs to be re celled. Can anyone recommend a good
supplier of sub c nicads?

Thanks,
Stephen.

Consider replacing with NiMhy cells as they are much more readily
available, especially in the Sub C size and especially good quality
ones. Also, Nicads have to be specially re-cycled at considerable
expense to remove the very nasty cadmium.

NiMhy cells have a much less definite 'peak' than Nicads and so a
NiMhy capable charger must be used. Additionally, if you charge them
too slowly they won't show a peak and the charger will just keep
going. There have been fires. I recommend a charger with a temperature
sensor to cut off the charge (in addition to the delta peak cut off).

When we used to use NiMhy cells for high current aeromodelling
applications the GP 3300 sub C cells were a favourite, capable of many
hundreds of amps when warm. I don't know about self discharge, though,
as we used to fast charge them for every flight and they were pretty
much empty after each one. We all use Lipo cells now (mainly because
they are so much lighter).

- Mike

On Sun, 21 Jun 2015 17:09:37 +0000 (UTC), Andrew Gabriel wrote:

yep, NiCd has more or less disappeared. NiHM is very similar but
without the major problems of NiCd, ie rapid self discharge and
the
"memory effect".

What about internal resistance? NiCd is very low, and I suspect
many power tools relied on that. Never measured NiMH.

Can't say I've noticed any in use preformance degredation between
NiCd and NiMH in the screwdriver so I'd guess that the internal
resistances are similar.

--
Cheers
Dave.

On Sun, 21 Jun 2015 12:16:28 +0100, Dave Plowman (News) wrote:

So you get out the power tool from the cupboard thinking 'I'll
just...' and it's flat - you need to wait to recharge it.

NiCd based drill is in that mode ATM. With the self discharge
period
about a week.

Really, if something really is used only occasionally, cordless is an
extremely expensive 'convenience'.

And actually a time waster if you have to wait while the batteries
charge.

That can be worked around with a bit of common sense. You know the
batteries are iffy, so when you start the job that needs that tool
the first thing you do is check it or put it on charge anyway. then
you get on collecting all the other bits you need and preparation by
which time teh tool will have picked up enough chrage to be useable
and can b put pack on charge during the task.

Trouble is it really is a gamble buying replacement cells - given how
much they influence the performance of most tools.

I find the GP industrial things from CPC etc satisfactory and good
value.

--
Cheers
Dave.

CB wrote:

I used these people about a year ago

http://www.batteriesplus.co.uk/acata...Batteries.html

I used this lot and they were hopeless. It was only after I ordered that
I looked up some reviews that all said they were slow and had to be
chased and, lo-and-behold, they were slow and I had to chase them.

The batteries were crap too. Re-did two Makita sub-C battery packs and
they were worse than the dying packs I'd stripped. May as well have
bought randomly from eBay at half the price.

--
Scott

Where are we going and why am I in this handbasket?

In article ,
Mike wrote:
Consider replacing with NiMhy cells as they are much more readily
available, especially in the Sub C size and especially good quality
ones.

Can you recommend a supplier of good quality Sub-C sizes?

--
*How can I miss you if you won't go away?

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

On Tuesday, 23 June 2015 00:13:06 UTC+1, Dave Liquorice wrote:
On Sun, 21 Jun 2015 17:09:37 +0000 (UTC), Andrew Gabriel wrote:

yep, NiCd has more or less disappeared. NiHM is very similar but
without the major problems of NiCd, ie rapid self discharge and
the
"memory effect".

What about internal resistance? NiCd is very low, and I suspect
many power tools relied on that. Never measured NiMH.

Can't say I've noticed any in use preformance degredation between
NiCd and NiMH in the screwdriver so I'd guess that the internal
resistances are similar.

Screwdrivers are quite low current draw compared to cordless drills.

FWIW the memory effect of NiCds was grossly exaggerated


NT

wrote in message
...

On Tuesday, 23 June 2015 00:13:06 UTC+1, Dave Liquorice wrote:
On Sun, 21 Jun 2015 17:09:37 +0000 (UTC), Andrew Gabriel wrote:

yep, NiCd has more or less disappeared. NiHM is very similar but
without the major problems of NiCd, ie rapid self discharge and
the
"memory effect".

What about internal resistance? NiCd is very low, and I suspect
many power tools relied on that. Never measured NiMH.

Can't say I've noticed any in use preformance degredation between
NiCd and NiMH in the screwdriver so I'd guess that the internal
resistances are similar.

Screwdrivers are quite low current draw compared to cordless drills.

FWIW the memory effect of NiCds was grossly exaggerated


NT

Whisker growth is the main problem in my experience, where one cell gets
shorted out internally. I have Nicad packs for my Paslode nail gun, one of
which does this quite regularly. Easily sorted by a quite zap across a car
battery - the pack is 9.6 volts iirc and the quick pulse of high current
(12v battery and lowish internal cell resistance) pops the grown strand very
effectively.

Andrew

In article ,
wrote:
Can't say I've noticed any in use preformance degredation between
NiCd and NiMH in the screwdriver so I'd guess that the internal
resistances are similar.

Screwdrivers are quite low current draw compared to cordless drills.

Don't think so. They can be stalled if trying to turn a large enough screw.

And screwdrivers generally have smaller batteries.

--
*I want it all and I want it delivered

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

On Wednesday, 24 June 2015 10:54:01 UTC+1, Dave Plowman (News) wrote:
In article ,
nt wrote:
Can't say I've noticed any in use preformance degredation between
NiCd and NiMH in the screwdriver so I'd guess that the internal
resistances are similar.

Screwdrivers are quite low current draw compared to cordless drills.

Don't think so. They can be stalled if trying to turn a large enough screw.

And screwdrivers generally have smaller batteries.

both of those mean less current, as does lower top speed


NT

On Wed, 24 Jun 2015 06:39:56 -0700 (PDT), wrote:

Screwdrivers are quite low current draw compared to cordless
drills.

Don't think so. They can be stalled if trying to turn a large
enough
screw.

And screwdrivers generally have smaller batteries.

both of those mean less current,

Er no a stalled DC motor is pretty much a dead short on the battery.
When a DC motor is whizzing round the back EMF reduces the current
draw.

--
Cheers
Dave.

In article ,
wrote:
On Wednesday, 24 June 2015 10:54:01 UTC+1, Dave Plowman (News) wrote:
In article ,
nt wrote:
Can't say I've noticed any in use preformance degredation between
NiCd and NiMH in the screwdriver so I'd guess that the internal
resistances are similar.

Screwdrivers are quite low current draw compared to cordless drills.

Don't think so. They can be stalled if trying to turn a large enough screw.

And screwdrivers generally have smaller batteries.

both of those mean less current, as does lower top speed


Everything being equal, the size of the battery determines maximum current.
The speed the spindle runs at is largely dependant on gearing.

--
*Why is it that most nudists are people you don't want to see naked?*

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

On Wednesday, 24 June 2015 16:58:06 UTC+1, Dave Liquorice wrote:
On Wed, 24 Jun 2015 06:39:56 -0700 (PDT), nt wrote:

Screwdrivers are quite low current draw compared to cordless
drills.

Don't think so. They can be stalled if trying to turn a large
enough
screw.

And screwdrivers generally have smaller batteries.

both of those mean less current,

Er no a stalled DC motor is pretty much a dead short on the battery.
When a DC motor is whizzing round the back EMF reduces the current
draw.

stall current is immaterial. The fact that its liable to stall means its taking less current when rotating.


NT

On Wednesday, 24 June 2015 18:16:28 UTC+1, Dave Plowman (News) wrote:
In article ,
nt wrote:
On Wednesday, 24 June 2015 10:54:01 UTC+1, Dave Plowman (News) wrote:
In article ,
nt wrote:
Can't say I've noticed any in use preformance degredation between
NiCd and NiMH in the screwdriver so I'd guess that the internal
resistances are similar.

Screwdrivers are quite low current draw compared to cordless drills.

Don't think so. They can be stalled if trying to turn a large enough screw.

And screwdrivers generally have smaller batteries.

both of those mean less current, as does lower top speed


Everything being equal, the size of the battery determines maximum current.
The speed the spindle runs at is largely dependant on gearing.

current times voltage = power, which is proportional to torque times speed. Half the spindle speed, if torque is the same, means half the battery curent.


NT

On Sun, 21 Jun 2015 11:20:20 +0100, The Natural Philosopher wrote:

On 21/06/15 10:42, Dave Liquorice wrote:
On Sat, 20 Jun 2015 07:13:46 +0000 (UTC), Andrew Gabriel wrote:

About 6 months ago, I tried to locate a supplier for someone else's
drill, and a few suppliers told me they can no longer get NiCd cells
made - they still have stock of the common sizes, but not the sub-C.

yep, NiCd has more or less disappeared. NiHM is very similar but
without the major problems of NiCd, ie rapid self discharge and the
"memory effect".

Actually NiMh is worse at self discharge than NiCd and is also more
damaged by being flattened.

NiCd disappeared because of cadmium, which is a metal that it is
politically incorrect to use, and because NiMh is a bit more energy
dense.


"a bit more energy dense" ?

How about "Three times the energy density." ?

You can get AA NiMH cells with capacities up to (and possibly over) the
3AH mark these days. At this extreme, they won't be the Low Self
Discharge (LSD) type.

The highest capacity AA NiMH LSD cells that I've actually been able to
acquire recently (some time during the past 18/24 months) were rated at
2.3AH and marked as Tronic "Eco ready to use" where the expression "ready
to use" is simply marketing speak for the LSD type which, unlike the
ordinary NiMH cells, don't require being recharged before being placed
into service.

This effectively allows them to be just as usable as a primary cell
equivalent but with the benefit of being rechargeable after they've been
exhausted rather than ending up in the "Spent Batteries Box" in Aldididdle
(hence the legitimate use of the 'word' "Eco" in its description).

When I first bought a set of 6 AA NiCds for a (still functioning!)
electronic calculator back in the late 70s, they were only 0.45AH
capacity. Over the years, I saw the capacity of AA NiCds go to 0.5AH,
then 0.6AH and finally, ime, a monster capacity of 0.7AH. They may have
peaked at 0.8AH but I can't recall with any certainty whether such high
capacity AA NiCds were marketed before NiMH developments had rendered
such 'high capacity' NiCd cells just a little bit pointless.

The lowest capacity NiMH AA cells I ever used were a two cell set
supplied with a little 3MPxl Nikon CoolPix I bought ten years ago and
these were rated at 2AH. I think the lowest capacity NiMH AA cells I ever
saw had a 1.8AH rating. With that in mind, I think it *is* fair to say
that NiMH cells have, at a conservative estimate, three times the
capacity of the NiCd equivalent.

Portable electronic kit (radios and digital cameras) *properly* designed
to be powered from AA and AAA cells are designed for an end point voltage
of, typically, 1 volt per cell with primary cells (Zinc/Carbon or
alkaline). The rechargable cells, both NiCd and NiMH, can be considered
to be exhausted as soon as they drop to 1.2v, well above the endpoint
voltage for primary cells.

Bearing this in mind, it may be somewhat disconcerting to discover that
a set of rechargeables used in a P&S digital camera swiftly start to show
'Low Battery' after only a few charge/discharge cycles. The problem isn't
due to defficiencies in the battery chemistry but down to high contact
resistance due to tarnishing of the battery contacts. This combined with
the low initial voltage (1.35v versus 1.6v of a typical primary cell)
leads to spurious early 'Low Battery' warnings which can be 'cleared' by
cleaning the contacts and re-inserting the cells back into the battery
compartment.

The problem is absent when using primary cells simply because of their
'one shot' nature. They're never recycled once their pitifully short life
has expired so their contacts remain in pristine condition when used in a
camera. Also, any contact resistance is swamped by the higher internal
resistance with the higher cell voltage effectively compensating for such
volt drops.

If the manufacturers of such AA cell powered cameras were to redesign
the battery compartments to use much stronger contact pressures and
permit a sliding contact action on insertion of the cells, there'd be a
lot less trouble from such spurious low battery voltage warnings.
Unfortunately, there's only so much strength in a plastic battery holder
and too much pressure to keep the design nice and compact which limits
the scope for such niceties as a 'self cleaning' wiping contact battery
holder.

I used to be rather prejudiced against digital cameras that eschewed the
use of cheap commodity AA cell power for proprietary Li-Ion battery packs
but after my experience with AA powered cameras, I've rather changed my
mind.

Although the camera makers own replacement Li-ion battery packs are eye-
wateringly expensive, you can actualy get hold of decent third party
equivalents for not much more than the cost of the watt hour equivilent
in NiMH power.

The relatively expensive Li-ion battery (even when using a 'cheaper
substitute') does have the merit of being able to employ gold plated
contacts (nicely matching the gold plated battery contacts in the camera)
which eliminates, at a stroke, the main deficiency inherent in using
rechargeable AA cells.

Now when I see the low battery warning in my super zoom bridge camera
(Canon SX40HS)'s viewfinder, I can be pretty certain it has everything to
do with the state of the battery rather than a battery contact problem.

--
Johnny B Good

Portable electronic kit (radios and digital cameras) *properly* designed
to be powered from AA and AAA cells are designed for an end point voltage
of, typically, 1 volt per cell with primary cells (Zinc/Carbon or
alkaline). The rechargable cells, both NiCd and NiMH, can be considered
to be exhausted as soon as they drop to 1.2v, well above the endpoint
voltage for primary cells.




Bearing this in mind, it may be somewhat disconcerting to discover that
a set of rechargeables used in a P&S digital camera swiftly start to show
'Low Battery' after only a few charge/discharge cycles. The problem isn't
due to defficiencies in the battery chemistry but down to high contact
resistance due to tarnishing of the battery contacts. This combined with
the low initial voltage (1.35v versus 1.6v of a typical primary cell)
leads to spurious early 'Low Battery' warnings which can be 'cleared' by
cleaning the contacts and re-inserting the cells back into the battery
compartment.


Had exactly that problem, just as you describe it!...
--
Tony Sayer