Have a much loved ancient Ryobi hobby drill which takes 4 AA cells.
Obviously, they've been replaced over the years. Probably originally
Ni-Cads.

Checking the current the device can take at near stall speed with a bench
top power supply, shows it can take up to about 2.5 amps at 4.8v.

Checking all the AA cells (NiMH) I have lying around by going across them
with a DVM set to 10 amps shows the most the best can deliver is under 2
amps - and the worst very much less at about 1/2 amp.

Any make to go for as replacements? Capacity isn't that important as it
only gets used occasionally.

I'd love to find another tool that is so convenient as this one for the
sort of things I use it for. Most of the current cordless ones are a lot
bigger and less wieldy.

--
*Oh, what a tangled website we weave when first we practice *

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

On 2015-11-30 10:34:43 +0000, Dave Plowman (News) said:

Have a much loved ancient Ryobi hobby drill which takes 4 AA cells.
Obviously, they've been replaced over the years. Probably originally
Ni-Cads.

Checking the current the device can take at near stall speed with a bench
top power supply, shows it can take up to about 2.5 amps at 4.8v.

Checking all the AA cells (NiMH) I have lying around by going across them
with a DVM set to 10 amps shows the most the best can deliver is under 2
amps - and the worst very much less at about 1/2 amp.

Any make to go for as replacements? Capacity isn't that important as it
only gets used occasionally.

Which? gives these three as best buys:

Duracell Recharge Ultra (2,500 mAh - these came in in Sept 2015) - rating 79%
Panasonic Eneloop Pro - 78%
Duracell Recharge Ultra (2,400 mAh) - 77%

These have the best high drain lifetime and also a good charge
retention, although thety ate not the best in time to charge.

E.

eastender wrote:
On 2015-11-30 10:34:43 +0000, Dave Plowman (News) said:

Have a much loved ancient Ryobi hobby drill which takes 4 AA cells.
Obviously, they've been replaced over the years. Probably originally
Ni-Cads.

Checking the current the device can take at near stall speed with a bench
top power supply, shows it can take up to about 2.5 amps at 4.8v.

Checking all the AA cells (NiMH) I have lying around by going across them
with a DVM set to 10 amps shows the most the best can deliver is under 2
amps - and the worst very much less at about 1/2 amp.

Any make to go for as replacements? Capacity isn't that important as it
only gets used occasionally.

Which? gives these three as best buys:

Duracell Recharge Ultra (2,500 mAh - these came in in Sept 2015) -
rating 79%
Panasonic Eneloop Pro - 78%
Duracell Recharge Ultra (2,400 mAh) - 77%

These have the best high drain lifetime and also a good charge
retention, although thety ate not the best in time to charge.

E.





I'd agree that the "pre-charged" type are possibly the best to go for as
not only do they tend come from the big brands but also have very much
lower self discharge which is essential for a less regularly used power
tool. Ordinary NiMh cell will almost certainly be flat/low state of
charge simply down to self discharge, each time you come to use the tool

Dave Plowman (News) wrote:
Have a much loved ancient Ryobi hobby drill which takes 4 AA cells.
Obviously, they've been replaced over the years. Probably originally
Ni-Cads.

Checking the current the device can take at near stall speed with a bench
top power supply, shows it can take up to about 2.5 amps at 4.8v.

Checking all the AA cells (NiMH) I have lying around by going across them
with a DVM set to 10 amps shows the most the best can deliver is under 2
amps - and the worst very much less at about 1/2 amp.

Any make to go for as replacements? Capacity isn't that important as it
only gets used occasionally.

I'd love to find another tool that is so convenient as this one for the
sort of things I use it for. Most of the current cordless ones are a lot
bigger and less wieldy.


I buy Xtreme rechargables, from Amazon.

On 30/11/15 11:27, Bob Minchin wrote:
Ordinary NiMh cell will almost certainly be flat/low state of charge
simply down to self discharge, each time you come to use the tool

And unlike NiCd, they are permanently damaged by going flat.


--
the biggest threat to humanity comes from socialism, which has utterly
diverted our attention away from what really matters to our existential
survival, to indulging in navel gazing and faux moral investigations
into what the world ought to be, whilst we fail utterly to deal with
what it actually is.

On Mon, 30 Nov 2015 11:27:27 +0000, Bob Minchin wrote:

eastender wrote:
On 2015-11-30 10:34:43 +0000, Dave Plowman (News) said:

Have a much loved ancient Ryobi hobby drill which takes 4 AA cells.
Obviously, they've been replaced over the years. Probably originally
Ni-Cads.

Checking the current the device can take at near stall speed with a
bench top power supply, shows it can take up to about 2.5 amps at
4.8v.

Checking all the AA cells (NiMH) I have lying around by going across
them with a DVM set to 10 amps shows the most the best can deliver is
under 2 amps - and the worst very much less at about 1/2 amp.

Any make to go for as replacements? Capacity isn't that important as
it only gets used occasionally.

Which? gives these three as best buys:

Duracell Recharge Ultra (2,500 mAh - these came in in Sept 2015) -
rating 79%
Panasonic Eneloop Pro - 78%
Duracell Recharge Ultra (2,400 mAh) - 77%

These have the best high drain lifetime and also a good charge
retention, although thety ate not the best in time to charge.

E.





I'd agree that the "pre-charged" type are possibly the best to go for as
not only do they tend come from the big brands but also have very much
lower self discharge which is essential for a less regularly used power
tool. Ordinary NiMh cell will almost certainly be flat/low state of
charge simply down to self discharge, each time you come to use the tool

There's a reason they came with Ni-Cads. They have three times the
discharge rate that Ni-mh ones do, so your drill won't stall. Get some
more and charge the thing every month regardless - sorted.

On 30/11/15 10:34, Dave Plowman (News) wrote:
Have a much loved ancient Ryobi hobby drill which takes 4 AA cells.
Obviously, they've been replaced over the years. Probably originally
Ni-Cads.

Checking the current the device can take at near stall speed with a bench
top power supply, shows it can take up to about 2.5 amps at 4.8v.

Checking all the AA cells (NiMH) I have lying around by going across them
with a DVM set to 10 amps shows the most the best can deliver is under 2
amps - and the worst very much less at about 1/2 amp.

Any make to go for as replacements? Capacity isn't that important as it
only gets used occasionally.

I'd love to find another tool that is so convenient as this one for the
sort of things I use it for. Most of the current cordless ones are a lot
bigger and less wieldy.


I like Panasonic Eneloop Pros

On 30/11/2015 10:34, Dave Plowman (News) wrote:

Have a much loved ancient Ryobi hobby drill which takes 4 AA cells.
Obviously, they've been replaced over the years. Probably originally
Ni-Cads.

Checking the current the device can take at near stall speed with a bench
top power supply, shows it can take up to about 2.5 amps at 4.8v.

Checking all the AA cells (NiMH) I have lying around by going across them
with a DVM set to 10 amps shows the most the best can deliver is under 2
amps - and the worst very much less at about 1/2 amp.

Any make to go for as replacements? Capacity isn't that important as it
only gets used occasionally.

Using NiCads will get you the higher stall current. Otherwise try NiMH
with the low self discharge feature or be prepared to always be cursing
your drill for being flat and the batteries to a short painful life.

I find the red ones sold precharged in Aldi/Lidl from time to time about
as good as any. Can't remember which one does them.

--
Regards,
Martin Brown

I don't know ho really makes them but I've been impressed by the ones
branded as Maplin recently.

Half the issue I find with high current devices are the battery holders
which corode at rivets and on the surfaces where the battery connects after
a few years.
Brian

--
From the Sofa of Brian Gaff Reply address is active
Remember, if you don't like where I post
or what I say, you don't have to
read my posts! :-)
"eastender" wrote in message
news:2015113011220470951-email@domaincom...
On 2015-11-30 10:34:43 +0000, Dave Plowman (News) said:

Have a much loved ancient Ryobi hobby drill which takes 4 AA cells.
Obviously, they've been replaced over the years. Probably originally
Ni-Cads.

Checking the current the device can take at near stall speed with a bench
top power supply, shows it can take up to about 2.5 amps at 4.8v.

Checking all the AA cells (NiMH) I have lying around by going across them
with a DVM set to 10 amps shows the most the best can deliver is under 2
amps - and the worst very much less at about 1/2 amp.

Any make to go for as replacements? Capacity isn't that important as it
only gets used occasionally.

Which? gives these three as best buys:

Duracell Recharge Ultra (2,500 mAh - these came in in Sept 2015) - rating
79%
Panasonic Eneloop Pro - 78%
Duracell Recharge Ultra (2,400 mAh) - 77%

These have the best high drain lifetime and also a good charge retention,
although thety ate not the best in time to charge.

E.

Yes, but most are now the new ones with low self discharge. the whole snag
with rechargeable when used in series is the fact that if one cell
discharges to a low voltage it is reverse charged by the others through the
load, and as has been said, no rechargeable likes this for very long.
Brian

--
From the Sofa of Brian Gaff Reply address is active
Remember, if you don't like where I post
or what I say, you don't have to
read my posts! :-)
"The Natural Philosopher" wrote in message
...
On 30/11/15 11:27, Bob Minchin wrote:
Ordinary NiMh cell will almost certainly be flat/low state of charge
simply down to self discharge, each time you come to use the tool

And unlike NiCd, they are permanently damaged by going flat.


--
the biggest threat to humanity comes from socialism, which has utterly
diverted our attention away from what really matters to our existential
survival, to indulging in navel gazing and faux moral investigations into
what the world ought to be, whilst we fail utterly to deal with what it
actually is.

In article ,
pamela wrote:
The following (slightly dated) test shows AA Eneloops continuously
delivering 10 amps for over an hour. Other brands too.

If only. ;-)

--
*Money isn't everything, but it sure keeps the kids in touch *

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

pamela wrote:

10 amps seems like a stonkingly high current from a single
cell but that's what the test report is saying.

Look closely, it's just a _very_ small decimal point in 1.0A

pamela wrote:

Andy Burns wrote:

Look closely, it's just a _very_ small decimal point in 1.0A

The legend to the charts clearly shows "10.0 Amp Test" and the posts
also discuss 10 amps.

Oh sorry, I hadn't scrolled down half a mile to that section!

I suppose 10 amps is theoretically posible

It seems to last under 10 minutes, rather than over an hour as
originally stated

pamela wrote:

The following (slightly dated) test shows AA Eneloops continuously
delivering 10 amps for over an hour. Other brands too.

http://www.candlepowerforums.com/vb/...-NiMh-Battery-
Shoot-Out&p=920843#post920843

Ay? 10 AmpHour AA Cells, I don't think so!

Did you mean 1.0 amps for over an hour?

--
Chris Green
·

In article ,
pamela wrote:
On 13:47 30 Nov 2015, Dave Plowman (News) wrote:

In article ,
pamela wrote:
The following (slightly dated) test shows AA Eneloops continuously
delivering 10 amps for over an hour. Other brands too.

If only. ;-)


Got to admit 10 amps seems like a stonkingly high current from a single
cell but that's what the test report is saying. I didn't read all the
details but I saw the charts.

10 amps for one hour would suggest a capacity of approaching 10 amp hours.

AAs are more like 2.5 amp hours. (2500 mA.hr) But probably could manage
nothing like 2.5 amps for an hour.

--
*Ever stop to think and forget to start again?

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

On 30/11/2015 13:47, Dave Plowman (News) wrote:
In article ,
pamela wrote:

The following (slightly dated) test shows AA Eneloops continuously
delivering 10 amps for over an hour. Other brands too.

If only. ;-)

There is something wrong there. At 10A discharge rate AAs start getting
awfully warm by about 30s and could explode after less than 5 minutes.

Most AA's can't get anywhere near that current. Alkalines will though.

Even at 1A continuous current the nominal 2.5Ah capacity or so is
already 10% less than you would get at a low current discharge rate.

--
Regards,
Martin Brown

pamela wrote:

Oh, I think I know what you're referring to.

The axis says "AmpHours" and not "Hours" as I thought it did. My
mistake. I'm asleep at the wheel. So that's where your 10 minutes is
coming from.

If I'm looking the same graph as you (originally I was looking at the
table at the top with the almost invisible decimal point) I just read
the 9.4 minutes from the legend.

On 30/11/2015 13:06, pamela wrote:
On 12:48 30 Nov 2015, Martin Brown wrote:

On 30/11/2015 10:34, Dave Plowman (News) wrote:

Have a much loved ancient Ryobi hobby drill which takes 4 AA cells.
Obviously, they've been replaced over the years. Probably originally
Ni-Cads.

Checking the current the device can take at near stall speed with a
bench top power supply, shows it can take up to about 2.5 amps at
4.8v.

Checking all the AA cells (NiMH) I have lying around by going across
them with a DVM set to 10 amps shows the most the best can deliver is
under 2 amps - and the worst very much less at about 1/2 amp.

Any make to go for as replacements? Capacity isn't that important as
it only gets used occasionally.

Using NiCads will get you the higher stall current. Otherwise try NiMH
with the low self discharge feature or be prepared to always be
cursing your drill for being flat and the batteries to a short painful
life.

I find the red ones sold precharged in Aldi/Lidl from time to time
about as good as any. Can't remember which one does them.


Agreed. NiCads perform better but:

Unreliable manufacture meant many of my AA NiCads packed up early.
Inconvenient due to low capacity and self discharge compared to NiMH.
Possible memory effect. Harder to find and higher prices.

I aim for an easy life. If Eneloops drive the drill then use them. I'm
not sure Aldi/Lidl cells would perform as well as Eneloops although I
wonder if they may be re-badged Ansmann which is what some of their
chargers are.


So far, impressed with some Lidl Cs and AAs. Best of the wide range of
rechargeables I have are Contour AAs. These:

http://www.box.co.uk/Contour_Energy_...1215441.h tml

They do variations on the theme - it's the ready to use 2100mAh ones
that I have, as per the link

--
Cheers, Rob

Martin Brown wrote:
On 30/11/2015 13:47, Dave Plowman (News) wrote:
In article ,
pamela wrote:

The following (slightly dated) test shows AA Eneloops continuously
delivering 10 amps for over an hour. Other brands too.

If only. ;-)

There is something wrong there. At 10A discharge rate AAs start getting
awfully warm by about 30s and could explode after less than 5 minutes.

Most AA's can't get anywhere near that current. Alkalines will though.

Even at 1A continuous current the nominal 2.5Ah capacity or so is
already 10% less than you would get at a low current discharge rate.

NiCd as opposed to NiMh can probably cope with the high current, but
won't last very long of course (as in will need recharging).

--
Chris Green
·

Bit more investigation showed the motor has a shorted turn or two on some
of the armature windings. Very different resistance readings as it is
edged round.

So basically scrap. Nothing to do with the batteries. ;-)

--
*If at first you don't succeed, then skydiving definitely isn't for you *

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

In article ,
Jonno wrote:
Dave Plowman (News) scribbled


Bit more investigation showed the motor has a shorted turn or two on
some of the armature windings. Very different resistance readings as
it is edged round.

So basically scrap. Nothing to do with the batteries. ;-)


Now you know what you want for Xmas.

Wish they still made the identical one. It was just so right for me. The
ones on the market these days are bigger - especially in diameter so not
so nice to use.

Other good thing was returning it to its stand put it on charge. No need
to fiddle with a plug or remove the battery pack. And a press to run
switch you could use with the same hand as you hold it in - no silly
'safety' locks.

--
*Why is it that rain drops but snow falls?

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