I was going through my collection of rechargeable batteries, sorting
the wheat from the chaff and because many seemed to be pretty low on
capacity / dead (or waiting for attempted resurrection), I ordered
some Amazon Basics 'Ready to use' NiMh AA's (2000mAh) and AAA's
(800mAh).

Now, on the AAA's it states the 'Standard charge is 80mA for 16 hours'
and I presume by that they mean '... to get the best life / cycles out
of the cell'.

Now, the lowest current charger I have here is 200mA (apart from my
fully configurable one that goes down to 10mA but is only single cell
(for Ni-Mh per cell monitoring)) and I think the charger they often
sell with the cells is 375mA for AAA?

Now, we know one of the biggest killer of most rechargeable battery
chemistry's is heat so I'm very conscious of that with any charging
solution.

I 'get' that some people need their batteries re-charged asap (I knew
a wedding photographer who really cained his and treated his
high-capacity rechargeables as consumables) but for most of us,
wouldn't 'overnight' be ok [1]?

Does anyone know of a multi-cell / intelligent NiMh ( NiMH only would
be ok) charger that would take a minimum of 1 to 4 cells (not in pairs
as some torches and the like have 3 cells) and with either 100mA
charge option for AAA's or user setable down that low please?

The default minimum charge rate of 200mA is fine for the 2000mAh AA's
and my Youshiko YC4000 does that very well. [2]

Cheers, T i m

[1] No battery should be left 'Unattended' whilst on charge but if
charging at a low rate (C/10 or greater etc) the risk should be pretty
low.

[2] It has a refresh option that repeatedly charges and discharges the
cell(s) until it hits the peak capacity and then reports it, It take
any mix of 4 x AA/AAA, NiCd/ NiMh, charges at 200 (default), 500, 700,
or 1000mA (and discharges at 50% of each of those values) and (each
slot) any one of 4 programs (Charge, Discharge, Refresh or Test).

On Tue, 17 Nov 2020 11:36:16 +0000, T i m wrote:

I was going through my collection of rechargeable batteries, sorting the
wheat from the chaff and because many seemed to be pretty low on
capacity / dead (or waiting for attempted resurrection), I ordered some
Amazon Basics 'Ready to use' NiMh AA's (2000mAh) and AAA's (800mAh).

Now, on the AAA's it states the 'Standard charge is 80mA for 16 hours'
and I presume by that they mean '... to get the best life / cycles out
of the cell'.

Now, the lowest current charger I have here is 200mA (apart from my
fully configurable one that goes down to 10mA but is only single cell
(for Ni-Mh per cell monitoring)) and I think the charger they often sell
with the cells is 375mA for AAA?

Now, we know one of the biggest killer of most rechargeable battery
chemistry's is heat so I'm very conscious of that with any charging
solution.

I 'get' that some people need their batteries re-charged asap (I knew a
wedding photographer who really cained his and treated his high-capacity
rechargeables as consumables) but for most of us, wouldn't 'overnight'
be ok [1]?

Does anyone know of a multi-cell / intelligent NiMh ( NiMH only would
be ok) charger that would take a minimum of 1 to 4 cells (not in pairs
as some torches and the like have 3 cells) and with either 100mA charge
option for AAA's or user setable down that low please?

The default minimum charge rate of 200mA is fine for the 2000mAh AA's
and my Youshiko YC4000 does that very well. [2]

Cheers, T i m

[1] No battery should be left 'Unattended' whilst on charge but if
charging at a low rate (C/10 or greater etc) the risk should be pretty
low.

[2] It has a refresh option that repeatedly charges and discharges the
cell(s) until it hits the peak capacity and then reports it, It take any
mix of 4 x AA/AAA, NiCd/ NiMh, charges at 200 (default), 500, 700,
or 1000mA (and discharges at 50% of each of those values) and (each
slot) any one of 4 programs (Charge, Discharge, Refresh or Test).

https://www.ebay.co.uk/i/38369854044...110006%26algo%
3DHOMESPLICE.SIM%26ao%3D2%26asc%3D20160908110712%2 6meid%
3Dadbcd27b2e2844d1aa9d3d6d195b9dad%26pid%3D100677% 26rk%3D6%26rkt%3D30%
26mehot%3Dlo%26sd%3D133550690909%26itm%3D383698540 442%26pmt%3D1%26noa%3D1%
26pg%3D2386202%26algv%3DDefaultOrganic%26brand%3DK eenstone

On Tue, 17 Nov 2020 11:36:16 +0000, T i m wrote:

Does anyone know of a multi-cell / intelligent NiMh ( NiMH only would
be ok) charger that would take a minimum of 1 to 4 cells (not in pairs
as some torches and the like have 3 cells) and with either 100mA
charge option for AAA's or user setable down that low please?

Nearest that I know is one that I bought after asking on here
https://www.7dayshop.com/products/ni...batteries-ntd4
It's out of stock on 7Day - that site seems to be short of many items - so
Ebay might be worth a try.
Standard is 350mA but each 'channel' (the bays are independent) can be set
to 175mA.
--
Peter.
The gods will stay away
whilst religions hold sway

On 11:36 17 Nov 2020, T i m said:

I was going through my collection of rechargeable batteries,
sorting the wheat from the chaff and because many seemed to be
pretty low on capacity / dead (or waiting for attempted
resurrection), I ordered some Amazon Basics 'Ready to use' NiMh
AA's (2000mAh) and AAA's (800mAh).

Now, on the AAA's it states the 'Standard charge is 80mA for 16
hours' and I presume by that they mean '... to get the best life /
cycles out of the cell'.

Now, the lowest current charger I have here is 200mA (apart from
my fully configurable one that goes down to 10mA but is only
single cell (for Ni-Mh per cell monitoring)) and I think the
charger they often sell with the cells is 375mA for AAA?

Surely that has been incorrectly taken from the standard advice to
slow charge a new battery for a long time (say 8 hours) to ensure
all cells reach max charge. Hard to see why it's applied to single
cells.

Now, we know one of the biggest killer of most rechargeable
battery chemistry's is heat so I'm very conscious of that with any
charging solution.

I 'get' that some people need their batteries re-charged asap (I
knew a wedding photographer who really cained his and treated his
high-capacity rechargeables as consumables) but for most of us,
wouldn't 'overnight' be ok [1]?

Does anyone know of a multi-cell / intelligent NiMh ( NiMH only
would be ok) charger that would take a minimum of 1 to 4 cells
(not in pairs as some torches and the like have 3 cells) and with
either 100mA charge option for AAA's or user setable down that low
please?

The default minimum charge rate of 200mA is fine for the 2000mAh
AA's and my Youshiko YC4000 does that very well. [2]

Cheers, T i m

[1] No battery should be left 'Unattended' whilst on charge but if
charging at a low rate (C/10 or greater etc) the risk should be
pretty low.

[2] It has a refresh option that repeatedly charges and discharges
the cell(s) until it hits the peak capacity and then reports it,
It take any mix of 4 x AA/AAA, NiCd/ NiMh, charges at 200
(default), 500, 700, or 1000mA (and discharges at 50% of each of
those values) and (each slot) any one of 4 programs (Charge,
Discharge, Refresh or Test).

That Youshiko YC4000 looks like a clone of the original La Crosse
BC-700, which is a nice charger.

NiMH has a faint "negative delta V" voltage drop at low charge
rates. If a charger uses that method (and no others) to determine
termination then the charger may miss it and overcharge the cell
causing vented gas that reduces capacity. For that reason some
people prefer to charge at no less than 0.5C (which is 400mA for the
AAAs).

There used to be a forum on charging at CandlePower which was quite
active. Here's a thread which goes into more detail than I have
time to read but seems to discuss this.

https://www.candlepowerforums.com/vb...178667-A-look-
at-slow-charging

On Tue, 17 Nov 2020 11:52:20 -0000 (UTC), jon wrote:

snip

Does anyone know of a multi-cell / intelligent NiMh ( NiMH only would
be ok) charger that would take a minimum of 1 to 4 cells (not in pairs
as some torches and the like have 3 cells) and with either 100mA charge
option for AAA's or user setable down that low please?

snip

https://www.ebay.co.uk/i/38369854044...110006%26algo%
3DHOMESPLICE.SIM%26ao%3D2%26asc%3D20160908110712% 26meid%
3Dadbcd27b2e2844d1aa9d3d6d195b9dad%26pid%3D100677 %26rk%3D6%26rkt%3D30%
26mehot%3Dlo%26sd%3D133550690909%26itm%3D38369854 0442%26pmt%3D1%26noa%3D1%
26pg%3D2386202%26algv%3DDefaultOrganic%26brand%3D Keenstone

Thanks for that. It's a bit like my Nitecore Digicharger D4EU. That
seems to have an (automatic) charge current of 375mA.

Looking at the spec of the one you linked it seems to suggest it only
goes down to 500mA, bit I'm not sure I trust it all:

"500mAh / 500mAh, means 2000mAh battery can be fully charged in 2
hours ..."?

Cheers, T i m

On Tue, 17 Nov 2020 12:01:54 +0000, PeterC
wrote:

On Tue, 17 Nov 2020 11:36:16 +0000, T i m wrote:

Does anyone know of a multi-cell / intelligent NiMh ( NiMH only would
be ok) charger that would take a minimum of 1 to 4 cells (not in pairs
as some torches and the like have 3 cells) and with either 100mA
charge option for AAA's or user setable down that low please?

Nearest that I know is one that I bought after asking on here
https://www.7dayshop.com/products/ni...batteries-ntd4
It's out of stock on 7Day - that site seems to be short of many items - so
Ebay might be worth a try.

Oh, I have already one of those (D4EU) Peter (and use it mainly for
18650's) and I have used it for the higher capacity AA's.

Standard is 350mA but each 'channel' (the bays are independent) can be set
to 175mA.

Oh, that's interesting (and would be handy if it could). OOI, I
currently have an AA and AAA in mine and both slots suggest they are
charging at 375mA.

Going on what you said though, I just had a play (what manual? g)
and found you can indeed toggle between '-dV/dt' and '-dV/dt Low' and
on low it drops to 150mA. ;-)

Whilst 150mA is still nearly twice the recommended value for the
AAA's, it's a bit better than the 200mA on the other charger so thanks
for that. ;-)

Cheers, T i m

T i m wrote:
I was going through my collection of rechargeable batteries, sorting
the wheat from the chaff and because many seemed to be pretty low on
capacity / dead (or waiting for attempted resurrection), I ordered
some Amazon Basics 'Ready to use' NiMh AA's (2000mAh) and AAA's
(800mAh).

Now, on the AAA's it states the 'Standard charge is 80mA for 16 hours'
and I presume by that they mean '... to get the best life / cycles out
of the cell'.

Now, the lowest current charger I have here is 200mA (apart from my
fully configurable one that goes down to 10mA but is only single cell
(for Ni-Mh per cell monitoring)) and I think the charger they often
sell with the cells is 375mA for AAA?

Now, we know one of the biggest killer of most rechargeable battery
chemistry's is heat so I'm very conscious of that with any charging
solution.

I 'get' that some people need their batteries re-charged asap (I knew
a wedding photographer who really cained his and treated his
high-capacity rechargeables as consumables) but for most of us,
wouldn't 'overnight' be ok [1]?

Does anyone know of a multi-cell / intelligent NiMh ( NiMH only would
be ok) charger that would take a minimum of 1 to 4 cells (not in pairs
as some torches and the like have 3 cells) and with either 100mA
charge option for AAA's or user setable down that low please?

The default minimum charge rate of 200mA is fine for the 2000mAh AA's
and my Youshiko YC4000 does that very well. [2]

Cheers, T i m

[1] No battery should be left 'Unattended' whilst on charge but if
charging at a low rate (C/10 or greater etc) the risk should be pretty
low.

[2] It has a refresh option that repeatedly charges and discharges the
cell(s) until it hits the peak capacity and then reports it, It take
any mix of 4 x AA/AAA, NiCd/ NiMh, charges at 200 (default), 500, 700,
or 1000mA (and discharges at 50% of each of those values) and (each
slot) any one of 4 programs (Charge, Discharge, Refresh or Test).

There's a decision tree of sorts, here.

https://www.powerstream.com/NiMH.htm

It's a target rich environment, in terms of charging
and charge termination methods.

Most charger manufacturers, they hate BOM cost, and
the odds of them putting thermistors in places they're
supposed to, is just about zero.

Paul

On Tue, 17 Nov 2020 12:13:56 GMT, Pamela
wrote:

snip

Now, on the AAA's it states the 'Standard charge is 80mA for 16
hours' and I presume by that they mean '... to get the best life /
cycles out of the cell'.

snip

Surely that has been incorrectly taken from the standard advice to
slow charge a new battery for a long time (say 8 hours) to ensure
all cells reach max charge. Hard to see why it's applied to single
cells.

Same thing though isn't it Pamela? A battery only (typically) being a
combination of single cells wired in series and so the current though
the battery = the current though each cell?

snip

That Youshiko YC4000 looks like a clone of the original La Crosse
BC-700, which is a nice charger.

Yup ;-)

I had one and it (eventually) died so I replaced it with that one.

NiMH has a faint "negative delta V" voltage drop at low charge
rates. If a charger uses that method (and no others) to determine
termination then the charger may miss it and overcharge the cell
causing vented gas that reduces capacity. For that reason some
people prefer to charge at no less than 0.5C (which is 400mA for the
AAAs).

Ok, makes sense.

There used to be a forum on charging at CandlePower which was quite
active. Here's a thread which goes into more detail than I have
time to read but seems to discuss this.

https://www.candlepowerforums.com/vb...178667-A-look-
at-slow-charging

Quick check

That looks very interesting / informative thanks. ;-)

Cheers, T i m

On Tue, 17 Nov 2020 08:17:50 -0500, Paul
wrote:

snip

Does anyone know of a multi-cell / intelligent NiMh ( NiMH only would
be ok) charger that would take a minimum of 1 to 4 cells (not in pairs
as some torches and the like have 3 cells) and with either 100mA
charge option for AAA's or user setable down that low please?

snip

There's a decision tree of sorts, here.

https://www.powerstream.com/NiMH.htm

It's a target rich environment, in terms of charging
and charge termination methods.

Yeah, thanks for that Paul.

Most charger manufacturers, they hate BOM cost, and
the odds of them putting thermistors in places they're
supposed to, is just about zero.

Yeah, I've read that elsewhere and judging how hot some of the cells
*have* become whilst charging seems to prove the thought. ;-(

Cheers, T i m

T i m wrote:
On Tue, 17 Nov 2020 12:13:56 GMT, Pamela
wrote:
Surely that has been incorrectly taken from the standard advice to
slow charge a new battery for a long time (say 8 hours) to ensure
all cells reach max charge. Hard to see why it's applied to single
cells.

Same thing though isn't it Pamela? A battery only (typically) being a
combination of single cells wired in series and so the current though
the battery = the current though each cell?

Yes and no. NiMH cells can tolerate a certain amount of overcharge without
damage - they just turn it into heat. In a pack, you aren't monitoring the
cell voltages (like you would in lithium ion) so you're applying a current
and hoping the cells take charge equally (ie that current x their cell
voltage is the amount of power they're taking) until you reach charge
termination of the whole pack. If the current is low, it doesn't matter if
cell A is fully charged and burns it off as heat while cell B is still
charging. But if it's higher the risk is cell A overcooks before B has
finished.

If you're charging a single cell you know charge termination is for that
cell alone and so you can run a higher current and still detect it
correctly.

Theo

On 17 Nov 2020 15:20:42 +0000 (GMT), Theo
wrote:

T i m wrote:
On Tue, 17 Nov 2020 12:13:56 GMT, Pamela
wrote:
Surely that has been incorrectly taken from the standard advice to
slow charge a new battery for a long time (say 8 hours) to ensure
all cells reach max charge. Hard to see why it's applied to single
cells.

Same thing though isn't it Pamela? A battery only (typically) being a
combination of single cells wired in series and so the current though
the battery = the current though each cell?

Yes and no.

I'll err on the side of 'Yes', given the context of these 'safe' low
current charging questions. ;-)

NiMH cells can tolerate a certain amount of overcharge without
damage - they just turn it into heat.

Sure, as you say, dependant on that level of 'heat' etc.

In a pack, you aren't monitoring the
cell voltages (like you would in lithium ion) so you're applying a current
and hoping the cells take charge equally (ie that current x their cell
voltage is the amount of power they're taking) until you reach charge
termination of the whole pack.

Agreed, and why when doing such it's often *safer* to do so at a low
current so any overcharging *doesn't* created an excess temperature
condition.

If the current is low, it doesn't matter if
cell A is fully charged and burns it off as heat while cell B is still
charging.

And what I believed the topic was on at that point in the
conversation, low current charging / chargers. [1]

You can have an overcharge *rate* even at the beginning of the charge
cycle etc.

I have a few 4.5AH NiMh D cells that have gone to sleep and the
terminal voltage is sufficiently depressed that my automatic charger
determines they are too low a voltage (below 1V) and so won't charge.
I put it on my new bench charger and gave it a couple of mins of 3A
(way above the suggested 900mA max) and it got noticeably warm in that
short time. (One has since been auto cycled on said charger and is
currently on a self discharge test, the others are waiting to see if
more 'shocks' might wake them up). ;-)

But if it's higher the risk is cell A overcooks before B has
finished.

Understood. When RC car racing we preferred 6 cell 'stick' packs
because each cell had (nearly) the same exposed surface area and / so
we could monitor the temperature and voltage of each cell easily.

If you're charging a single cell you know charge termination is for that
cell alone and so you can run a higher current and still detect it
correctly.

Understood (if that's what you are doing). ;-)

The same (worse?) issue occurs when discharging a non balanced battery
of course, where the weakest cell can end up becoming reverse charged,
helping to make it even weaker (and why I prefer chargers /
dischargers that treat each cell separately).

Cheers, T i m

[1] If the current is sufficiently low, it doesn't matter if any peak
(charge) detection doesn't work, as long as the charge is terminated
within a reasonable timescale (as you often see with cheap
rechargeable electronics that say 'Charge for at least 12 hours and
then disconnect from the charger').

On 13:27 17 Nov 2020, T i m said:
On Tue, 17 Nov 2020 12:13:56 GMT, Pamela wrote:


Now, on the AAA's it states the 'Standard charge is 80mA for 16
hours' and I presume by that they mean '... to get the best life
/ cycles out of the cell'.

snip

Surely that has been incorrectly taken from the standard advice to
slow charge a new battery for a long time (say 8 hours) to ensure
all cells reach max charge. Hard to see why it's applied to
single cells.

Same thing though isn't it Pamela? A battery only (typically)
being a combination of single cells wired in series and so the
current though the battery = the current though each cell?

If one cell in a battery (where the cells are in series not parallel)
is weaker than the others then it will overload during charge sooner. A
very low charge rate, say C/10, doesn't cause an NIMH cell to vent --
so it can be applied for much longer while all cells reach full charge.

Similarly on discharge to a low state, albeit not at issue here, a weak
cell in a battery can be forced into reverse polarity by the other
cells discharging normally -- as I have seen.

Anyway, the bottom line seems to be that a single NIMH cell doesn't
actually need a long low-current conditioning charge.

On Tue, 17 Nov 2020 11:36:16 +0000, T i m wrote:

I was going through my collection of rechargeable batteries, sorting the
wheat from the chaff and because many seemed to be pretty low on
capacity / dead (or waiting for attempted resurrection), I ordered some
Amazon Basics 'Ready to use' NiMh AA's (2000mAh) and AAA's (800mAh).

Now, on the AAA's it states the 'Standard charge is 80mA for 16 hours'
and I presume by that they mean '... to get the best life / cycles out
of the cell'.

Now, the lowest current charger I have here is 200mA (apart from my
fully configurable one that goes down to 10mA but is only single cell
(for Ni-Mh per cell monitoring)) and I think the charger they often sell
with the cells is 375mA for AAA?

Now, we know one of the biggest killer of most rechargeable battery
chemistry's is heat so I'm very conscious of that with any charging
solution.

I 'get' that some people need their batteries re-charged asap (I knew a
wedding photographer who really cained his and treated his high-capacity
rechargeables as consumables) but for most of us, wouldn't 'overnight'
be ok [1]?

Does anyone know of a multi-cell / intelligent NiMh ( NiMH only would
be ok) charger that would take a minimum of 1 to 4 cells (not in pairs
as some torches and the like have 3 cells) and with either 100mA charge
option for AAA's or user setable down that low please?

The default minimum charge rate of 200mA is fine for the 2000mAh AA's
and my Youshiko YC4000 does that very well. [2]

Cheers, T i m

[1] No battery should be left 'Unattended' whilst on charge but if
charging at a low rate (C/10 or greater etc) the risk should be pretty
low.

[2] It has a refresh option that repeatedly charges and discharges the
cell(s) until it hits the peak capacity and then reports it, It take any
mix of 4 x AA/AAA, NiCd/ NiMh, charges at 200 (default), 500, 700,
or 1000mA (and discharges at 50% of each of those values) and (each
slot) any one of 4 programs (Charge, Discharge, Refresh or Test).

I would hope capacitors would supercede cells eventually, but they are
expensive at the moment.

On 18/11/2020 12:41, jon wrote:
I would hope capacitors would supercede cells eventually, but they are
expensive at the moment.

Bless! Are you an Art Student?

Must be. Can't even spell supersede...

--
The theory of Communism may be summed up in one sentence: Abolish all
private property.

Karl Marx

On 18 Nov 2020 at 13:20:43 GMT, "The Natural Philosopher"
wrote:

On 18/11/2020 12:41, jon wrote:
I would hope capacitors would supercede cells eventually, but they are
expensive at the moment.

Bless! Are you an Art Student?

Must be. Can't even spell supersede...

I'm hoping for little, hand wound perpetual motion machines that just need
winding up every day to overcome losses will produce indefinite amounts of
electricity to replace batteries. You know, like when you stroke a dry cat on
a nylon carpet. I expect it is the insulation that is the biggest technical
problem.

--
Roger Hayter

On Wed, 18 Nov 2020 13:20:43 +0000, The Natural Philosopher wrote:

On 18/11/2020 12:41, jon wrote:
I would hope capacitors would supercede cells eventually, but they are
expensive at the moment.

Bless! Are you an Art Student?

Must be. Can't even spell supersede...


I must have been thinking of supercilious.

On 18/11/2020 13:49, Roger Hayter wrote:
On 18 Nov 2020 at 13:20:43 GMT, "The Natural Philosopher"
wrote:

On 18/11/2020 12:41, jon wrote:
I would hope capacitors would supercede cells eventually, but they are
expensive at the moment.

Bless! Are you an Art Student?

Must be. Can't even spell supersede...

I'm hoping for little, hand wound perpetual motion machines that just need
winding up every day to overcome losses will produce indefinite amounts of
electricity to replace batteries. You know, like when you stroke a dry cat on
a nylon carpet. I expect it is the insulation that is the biggest technical
problem.

I note today in my wry scan of the latest media ******** that the Scots
all wanted free public transport.

Well mine's a tireless ridable unicorn with wings. Thats what I want. I
think the government should respect my wishes, don't you?



--
Outside of a dog, a book is a man's best friend. Inside of a dog it's
too dark to read.

Groucho Marx

On 18/11/2020 13:49, Roger Hayter wrote:
On 18 Nov 2020 at 13:20:43 GMT, "The Natural Philosopher"
wrote:

On 18/11/2020 12:41, jon wrote:
I would hope capacitors would supercede cells eventually, but they are
expensive at the moment.

Bless! Are you an Art Student?

Must be. Can't even spell supersede...

I'm hoping for little, hand wound perpetual motion machines that just need
winding up every day to overcome losses will produce indefinite amounts of
electricity to replace batteries. You know, like when you stroke a dry cat on
a nylon carpet. I expect it is the insulation that is the biggest technical
problem.


Actually what I want is an an Atomic Aga. With back boiler. Running off
the decay heat of high level nuclear waste. When not employed cooking,
the heat is diverted to a back boiler for central heating and DHW, or to
a Stirling engine to generate electricity....

After 60 years you give the no longer hot waste back to Sellafield, and
receive another free brick of hot nuclides...

--
Outside of a dog, a book is a man's best friend. Inside of a dog it's
too dark to read.

Groucho Marx

On 18/11/2020 13:51, jon wrote:
On Wed, 18 Nov 2020 13:20:43 +0000, The Natural Philosopher wrote:

On 18/11/2020 12:41, jon wrote:
I would hope capacitors would supercede cells eventually, but they are
expensive at the moment.

Bless! Are you an Art Student?

Must be. Can't even spell supersede...


I must have been thinking of supercilious.

Can you do Thinking? Wow!

--
Climate Change: Socialism wearing a lab coat.

On 18 Nov 2020 at 13:52:27 GMT, "The Natural Philosopher"
wrote:

On 18/11/2020 13:49, Roger Hayter wrote:
On 18 Nov 2020 at 13:20:43 GMT, "The Natural Philosopher"
wrote:

On 18/11/2020 12:41, jon wrote:
I would hope capacitors would supercede cells eventually, but they are
expensive at the moment.

Bless! Are you an Art Student?

Must be. Can't even spell supersede...

I'm hoping for little, hand wound perpetual motion machines that just need
winding up every day to overcome losses will produce indefinite amounts of
electricity to replace batteries. You know, like when you stroke a dry cat
on
a nylon carpet. I expect it is the insulation that is the biggest technical
problem.

I note today in my wry scan of the latest media ******** that the Scots
all wanted free public transport.

Well mine's a tireless ridable unicorn with wings. Thats what I want. I
think the government should respect my wishes, don't you?

You may yet get your wish; you know the Government has nearly tied up a
wonderful post-Brexit trade deal with Fairyland?


--
Roger Hayter

On 18 Nov 2020 at 13:56:15 GMT, "The Natural Philosopher"
wrote:

On 18/11/2020 13:49, Roger Hayter wrote:
On 18 Nov 2020 at 13:20:43 GMT, "The Natural Philosopher"
wrote:

On 18/11/2020 12:41, jon wrote:
I would hope capacitors would supercede cells eventually, but they are
expensive at the moment.

Bless! Are you an Art Student?

Must be. Can't even spell supersede...

I'm hoping for little, hand wound perpetual motion machines that just need
winding up every day to overcome losses will produce indefinite amounts of
electricity to replace batteries. You know, like when you stroke a dry cat
on
a nylon carpet. I expect it is the insulation that is the biggest technical
problem.


Actually what I want is an an Atomic Aga. With back boiler. Running off
the decay heat of high level nuclear waste. When not employed cooking,
the heat is diverted to a back boiler for central heating and DHW, or to
a Stirling engine to generate electricity....

After 60 years you give the no longer hot waste back to Sellafield, and
receive another free brick of hot nuclides...

I suppose that is actually technically possible with a big lead bunker outside
- but not feasible engineering-wise because the nice bit of fresh Plutonium
you'd actually need would be too expensive. Plus all the compliance costs.

--
Roger Hayter

On 18 Nov 2020 at 13:51:30 GMT, "jon" wrote:

On Wed, 18 Nov 2020 13:20:43 +0000, The Natural Philosopher wrote:

On 18/11/2020 12:41, jon wrote:
I would hope capacitors would supercede cells eventually, but they are
expensive at the moment.

Bless! Are you an Art Student?

Must be. Can't even spell supersede...


I must have been thinking of supercilious.

Or even superfluous.

--
Roger Hayter

On Tue, 17 Nov 2020 13:15:10 +0000, T i m wrote:

On Tue, 17 Nov 2020 12:01:54 +0000, PeterC
wrote:

On Tue, 17 Nov 2020 11:36:16 +0000, T i m wrote:

Does anyone know of a multi-cell / intelligent NiMh ( NiMH only would
be ok) charger that would take a minimum of 1 to 4 cells (not in pairs
as some torches and the like have 3 cells) and with either 100mA
charge option for AAA's or user setable down that low please?

Nearest that I know is one that I bought after asking on here
https://www.7dayshop.com/products/ni...batteries-ntd4
It's out of stock on 7Day - that site seems to be short of many items - so
Ebay might be worth a try.

Oh, I have already one of those (D4EU) Peter (and use it mainly for
18650's) and I have used it for the higher capacity AA's.

Standard is 350mA but each 'channel' (the bays are independent) can be set
to 175mA.

Oh, that's interesting (and would be handy if it could). OOI, I
currently have an AA and AAA in mine and both slots suggest they are
charging at 375mA.

Going on what you said though, I just had a play (what manual? g)
and found you can indeed toggle between '-dV/dt' and '-dV/dt Low' and
on low it drops to 150mA. ;-)

Whilst 150mA is still nearly twice the recommended value for the
AAA's, it's a bit better than the 200mA on the other charger so thanks
for that. ;-)

Cheers, T i m

I found out by just pressing the 2 buttons - quite often a slightly longer
press will disclose another function. Pity that it doesn't hold that
setting.
Just in case you haven't found out, holding in the upper button for a couple
of seconds kills the display, almost - still dicernable in a good light but
no light for charging at night. I tend to charge overnight, as I won't go
out and leave anything on charge, just in case.
--
Peter.
The gods will stay away
whilst religions hold sway

On Tue, 17 Nov 2020 17:31:53 GMT, Pamela
wrote:

On 13:27 17 Nov 2020, T i m said:
On Tue, 17 Nov 2020 12:13:56 GMT, Pamela wrote:


Now, on the AAA's it states the 'Standard charge is 80mA for 16
hours' and I presume by that they mean '... to get the best life
/ cycles out of the cell'.

snip

Surely that has been incorrectly taken from the standard advice to
slow charge a new battery for a long time (say 8 hours) to ensure
all cells reach max charge. Hard to see why it's applied to
single cells.

Same thing though isn't it Pamela? A battery only (typically)
being a combination of single cells wired in series and so the
current though the battery = the current though each cell?

If one cell in a battery (where the cells are in series not parallel)
is weaker than the others then it will overload during charge sooner.

Agreed.

A
very low charge rate, say C/10, doesn't cause an NIMH cell to vent --
so it can be applied for much longer while all cells reach full charge.

Quite ... and why I was asking if anyone knew of a charger that
matched the published spec for the batteries (85mA)?

Similarly on discharge to a low state, albeit not at issue here, a weak
cell in a battery can be forced into reverse polarity by the other
cells discharging normally -- as I have seen.

Agreed.

Anyway, the bottom line seems to be that a single NIMH cell doesn't
actually need a long low-current conditioning charge.

I was just following the specification printed on the cells as I'm
sure that's what any supplier would reference if I entered a cycles
dispute with them?

eg. It doesn't say 'Initially charge for 85 mA and whatever you like
after that ...'?

I was willing to accept that Eneloop / 'Ready to use', low
self-discharge cells may be less able to accept a high charge rate
compared with 'High power' (but possibly high(er) self discharge)
cells, as my intended usage for most these new cells is for low power
use (like remote controls, DECT phones, PIR lights etc) but it may not
be the case (they may well accept or even prefer (for the reasons
stated on your link)), I higher rate than 85mA, for the charger to
properly detect -DeltaV.


Cheers, T i m

On Wed, 18 Nov 2020 15:08:30 +0000, PeterC
wrote:

snip

Whilst 150mA is still nearly twice the recommended value for the
AAA's, it's a bit better than the 200mA on the other charger so thanks
for that. ;-)


I found out by just pressing the 2 buttons - quite often a slightly longer
press will disclose another function.

Yeah, I think I had done / found that previously but didn't 'notice'
the practical consequences (I saw the setting change but not the
current so just set it back again)..

Pity that it doesn't hold that
setting.

Yeah.

Just in case you haven't found out, holding in the upper button for a couple
of seconds kills the display, almost - still dicernable in a good light but
no light for charging at night.

Funnily enough, yes, I have found that (by experiment) but with the
light I was in at the time, couldn't see much at all. I get people
turn them off when they have the charger on in their bedroom but that
backlight isn't particularly bright and there are plenty of other
things on with LED's in our bedroom for it not really notice if I had
the charger in there.

I tend to charge overnight, as I won't go
out and leave anything on charge, just in case.

I don't like leave things charging overnight because we *are* there
and asleep. I will leave some things charging when out (like the
YC4000 but typically only on the lowest settings and NiCad / NiMh.

Cheers, T i m

On 18/11/2020 14:15, Roger Hayter wrote:
On 18 Nov 2020 at 13:52:27 GMT, "The Natural Philosopher"
wrote:

On 18/11/2020 13:49, Roger Hayter wrote:
On 18 Nov 2020 at 13:20:43 GMT, "The Natural Philosopher"
wrote:

On 18/11/2020 12:41, jon wrote:
I would hope capacitors would supercede cells eventually, but they are
expensive at the moment.

Bless! Are you an Art Student?

Must be. Can't even spell supersede...

I'm hoping for little, hand wound perpetual motion machines that just need
winding up every day to overcome losses will produce indefinite amounts of
electricity to replace batteries. You know, like when you stroke a dry cat
on
a nylon carpet. I expect it is the insulation that is the biggest technical
problem.

I note today in my wry scan of the latest media ******** that the Scots
all wanted free public transport.

Well mine's a tireless ridable unicorn with wings. Thats what I want. I
think the government should respect my wishes, don't you?

You may yet get your wish; you know the Government has nearly tied up a
wonderful post-Brexit trade deal with Fairyland?


Yawn. Remoron.


--
"What do you think about Gay Marriage?"
"I don't."
"Don't what?"
"Think about Gay Marriage."

On 18/11/2020 14:17, Roger Hayter wrote:
On 18 Nov 2020 at 13:56:15 GMT, "The Natural Philosopher"
wrote:

On 18/11/2020 13:49, Roger Hayter wrote:
On 18 Nov 2020 at 13:20:43 GMT, "The Natural Philosopher"
wrote:

On 18/11/2020 12:41, jon wrote:
I would hope capacitors would supercede cells eventually, but they are
expensive at the moment.

Bless! Are you an Art Student?

Must be. Can't even spell supersede...

I'm hoping for little, hand wound perpetual motion machines that just need
winding up every day to overcome losses will produce indefinite amounts of
electricity to replace batteries. You know, like when you stroke a dry cat
on
a nylon carpet. I expect it is the insulation that is the biggest technical
problem.


Actually what I want is an an Atomic Aga. With back boiler. Running off
the decay heat of high level nuclear waste. When not employed cooking,
the heat is diverted to a back boiler for central heating and DHW, or to
a Stirling engine to generate electricity....

After 60 years you give the no longer hot waste back to Sellafield, and
receive another free brick of hot nuclides...

I suppose that is actually technically possible with a big lead bunker outside

Don't need a big lead bunker. Couple of inches of steel would be enough


- but not feasible engineering-wise because the nice bit of fresh Plutonium
you'd actually need would be too expensive. Plus all the compliance costs.

Not talking about plutonium, Engineering feasibility is not cost
related, that is commercial feasibility. Easily solved by throwing other
peoples money at it., Cf wind farms, battery banks, electric cars and
solar panels, none of which are commercially feasible, and as far as
compliance goes, follow wind farm example and rewrite the rules of
public health and safety.

You are an Art Student and I claim my £5.

I now hear that not only will you not be allowed to drive a fuel car,
but electric cars will be charged by the mile.

So everyone will stay at home and get drip fed propaganda about the
world outside.

Not just Scotland.



--
"What do you think about Gay Marriage?"
"I don't."
"Don't what?"
"Think about Gay Marriage."

On Tuesday, November 17, 2020 at 5:36:20 AM UTC-6, T i m wrote:
I was going through my collection of rechargeable batteries, sorting
the wheat from the chaff and because many seemed to be pretty low on
capacity / dead (or waiting for attempted resurrection), I ordered
some Amazon Basics 'Ready to use' NiMh AA's (2000mAh) and AAA's
(800mAh).

Now, on the AAA's it states the 'Standard charge is 80mA for 16 hours'
and I presume by that they mean '... to get the best life / cycles out
of the cell'.

Now, the lowest current charger I have here is 200mA (apart from my
fully configurable one that goes down to 10mA but is only single cell
(for Ni-Mh per cell monitoring)) and I think the charger they often
sell with the cells is 375mA for AAA?

Now, we know one of the biggest killer of most rechargeable battery
chemistry's is heat so I'm very conscious of that with any charging
solution.

I 'get' that some people need their batteries re-charged asap (I knew
a wedding photographer who really cained his and treated his
high-capacity rechargeables as consumables) but for most of us,
wouldn't 'overnight' be ok [1]?


I am hopeless on the recharger question. We had maybe a hundred different rechargers, wires all over the house. Not even sure what equipment or batteries they belonged to. Dad had hundreds of these things in his desk alone. batteries, battery rechargers, wires all over the desk. had to eventually throw them away because i could not match them up with anything.

I am equally bad with cameras. He had drawers and cabinets full of them. some from the 50s. Leicas I think

He gave me a few to take on trips. He said my photos were good, but I did not see anything special.

I ended up losing some too.

One time, I fully unpacked from a trip and the next morning while in the bathroom it occurred to me that I had not seen my camera. Anywho, I looked through all my bags and nothing.

Before leaving the ship, I checked the cabin at least 5-7 times. I think what may have happened was that I checked too many times, it was probably right in my face and I just forgot it. I think I may have left it on the table. I had a very good relationship with my cabin attendant and tipped him well. He seemed to be the type of guy who probably felt badly and turned it in. What may have happened after he turned it in (if that was the case) who knows?

I called the company and they gave me a reference number and told me the process for the situation. I did have the travel insurance. I got a lovely woman who advised that I wait the 30 days to see if it was turned in and then I can make my claim. I can claim the camera, case, memory card and even the batteries. they give 30 days to resolve these issues.

Unfortunately, I did take over 100 photos of gorgeous scenery and on the ship, plus people I met.

I am a tad upset but life could be worse. I saw some folks on board without arms and legs and with breathing tubes in wheelchairs so life could be much worse.

I do have one professional photo (taken with a shawl)

I know, call me an idiot. Lose cameras and batteries all over the place

mk5000


Equal to yo know seh
Not even the sea sea sure, a me meck yo feel sure
Ride pon da bike yah yo never detour
Is a R1 hi void by a d 4--Vybz Kartel €“ Mek Yuh Feel Sure

On Wed, 18 Nov 2020 19:01:38 +0000, T i m wrote:

I tend to charge overnight, as I won't go
out and leave anything on charge, just in case.

I don't like leave things charging overnight because we *are* there
and asleep. I will leave some things charging when out (like the
YC4000 but typically only on the lowest settings and NiCad / NiMh.

This is in the bedroom, fairly close to the smoke alarm. Taking 8h+ to
recharge AA cells probably isn't too risky.
--
Peter.
The gods will stay away
whilst religions hold sway

On Wed, 18 Nov 2020 22:42:22 +0000, PeterC
wrote:

On Wed, 18 Nov 2020 19:01:38 +0000, T i m wrote:

I tend to charge overnight, as I won't go
out and leave anything on charge, just in case.

I don't like leave things charging overnight because we *are* there
and asleep. I will leave some things charging when out (like the
YC4000 but typically only on the lowest settings and NiCad / NiMh.

This is in the bedroom, fairly close to the smoke alarm.

;-)

Taking 8h+ to
recharge AA cells probably isn't too risky.

Indeed and I make the same decision, along with noting that the spec
on the charger explicitly states that it's made out of non combustible
plastic etc.

I tested one of the batch of Amazon basics 10A NiMh D cells on my
iCharger (in a 3D printed 'high current' holder) the other day the
charged it on my Ansmann Energy 16 charger. It didn't seem to want to
indicate it was fully charged (theoretically taking at least 10 hours
at 1000mA) so I ended up putting it back on the iCharger to see what
that would do. It took an hour or so but then indicated it was
charged. Putting it back on the Ansmann, it then also indicated it was
charged after about an hour. So I'm hoping I just didn't give it
enough time and will be interested to see how the Ansmann copes with a
batch of 3 (xD's), assuming I ever actually discharge any in normal
use. They did all indicate fully charge when I first got them but that
was just a top-up. 'Technically' they suggest the highest capacity
charger can deal with is 9500mAh.

Along those lines, I came across a old fashioned but new torch the
other day (with a top handle and big reflector etc) that used the big
square battery 6V with springs (4R25). Looking around it suggested
that a similar torch with a xenon lamp would last for 7 hours on such
a battery but an LED replacement should last a lot longer. Then I
looked into seeing if I could 3D print a clip to take 4 x rechargeable
D cells as 1) I have quite a few and 2) using them would be more
flexible than the big square battery.

Then I found that such a thing already exists (4 x D to 4R25
converter) and you can sometimes get them with these bigger style
torches providing a battery choice option.

That said, the 4R25's can be bought quite cheaply, seem quite powerful
(10Ah?), seem to last a long time on the shelf and I've not found and
old one that has been flat / dead and leaked yet (but I guess they
might).

I've ordered some more 6V LED replacement lamps and with the 180
degree light pattern as these work better in such reflector lamps.

I have a more 'beam' orientated LED in my 4D Maglite as that better
suits my usage of it (and you do get some peripheral light in any
case).

Cheers, T i m

In article , The Natural Philosopher
writes
On 18/11/2020 12:41, jon wrote:
I would hope capacitors would supercede cells eventually, but they are
expensive at the moment.

Bless! Are you an Art Student?

Must be. Can't even spell supersede...

And answers a question that wasn't asked and doesn't answer the one that
was. He/She/It/Xi will go far.
--
bert

In article , T i m
writes
On Tue, 17 Nov 2020 17:31:53 GMT, Pamela
wrote:

On 13:27 17 Nov 2020, T i m said:
On Tue, 17 Nov 2020 12:13:56 GMT, Pamela wrote:


Now, on the AAA's it states the 'Standard charge is 80mA for 16
hours' and I presume by that they mean '... to get the best life
/ cycles out of the cell'.

snip

Surely that has been incorrectly taken from the standard advice to
slow charge a new battery for a long time (say 8 hours) to ensure
all cells reach max charge. Hard to see why it's applied to
single cells.

Same thing though isn't it Pamela? A battery only (typically)
being a combination of single cells wired in series and so the
current though the battery = the current though each cell?

If one cell in a battery (where the cells are in series not parallel)
is weaker than the others then it will overload during charge sooner.

Agreed.

A
very low charge rate, say C/10, doesn't cause an NIMH cell to vent --
so it can be applied for much longer while all cells reach full charge.

Quite ... and why I was asking if anyone knew of a charger that
matched the published spec for the batteries (85mA)?

Similarly on discharge to a low state, albeit not at issue here, a weak
cell in a battery can be forced into reverse polarity by the other
cells discharging normally -- as I have seen.

Agreed.

Anyway, the bottom line seems to be that a single NIMH cell doesn't
actually need a long low-current conditioning charge.

I was just following the specification printed on the cells as I'm
sure that's what any supplier would reference if I entered a cycles
dispute with them?

eg. It doesn't say 'Initially charge for 85 mA and whatever you like
after that ...'?

I was willing to accept that Eneloop / 'Ready to use', low
self-discharge cells may be less able to accept a high charge rate
compared with 'High power' (but possibly high(er) self discharge)
cells, as my intended usage for most these new cells is for low power
use (like remote controls, DECT phones, PIR lights etc) but it may not
be the case (they may well accept or even prefer (for the reasons
stated on your link)), I higher rate than 85mA, for the charger to
properly detect -DeltaV.


Cheers, T i m

My (very old) charger from jessops (remember them?)
Charges AAs @ 150mA and AAAs @ 50mA singles or pairs x 2
PP3 @ 16mA single or pair
Max Charging time 15 hrs by Timer Control.

More is not always better.
--
bert

On 14:19 20 Nov 2020, bert said:

In article , T i m
writes
On Tue, 17 Nov 2020 17:31:53 GMT, Pamela
wrote:

On 13:27 17 Nov 2020, T i m said:
On Tue, 17 Nov 2020 12:13:56 GMT, Pamela wrote:


Now, on the AAA's it states the 'Standard charge is 80mA for
16 hours' and I presume by that they mean '... to get the
best life / cycles out of the cell'.

snip

Surely that has been incorrectly taken from the standard advice
to slow charge a new battery for a long time (say 8 hours) to
ensure all cells reach max charge. Hard to see why it's
applied to single cells.

Same thing though isn't it Pamela? A battery only (typically)
being a combination of single cells wired in series and so the
current though the battery = the current though each cell?

If one cell in a battery (where the cells are in series not
parallel) is weaker than the others then it will overload during
charge sooner.

Agreed.

A
very low charge rate, say C/10, doesn't cause an NIMH cell to
vent -- so it can be applied for much longer while all cells
reach full charge.

Quite ... and why I was asking if anyone knew of a charger that
matched the published spec for the batteries (85mA)?

Similarly on discharge to a low state, albeit not at issue here,
a weak cell in a battery can be forced into reverse polarity by
the other cells discharging normally -- as I have seen.

Agreed.

Anyway, the bottom line seems to be that a single NIMH cell
doesn't actually need a long low-current conditioning charge.

I was just following the specification printed on the cells as I'm
sure that's what any supplier would reference if I entered a
cycles dispute with them?

eg. It doesn't say 'Initially charge for 85 mA and whatever you
like after that ...'?

I was willing to accept that Eneloop / 'Ready to use', low
self-discharge cells may be less able to accept a high charge rate
compared with 'High power' (but possibly high(er) self discharge)
cells, as my intended usage for most these new cells is for low
power use (like remote controls, DECT phones, PIR lights etc) but
it may not be the case (they may well accept or even prefer (for
the reasons stated on your link)), I higher rate than 85mA, for
the charger to properly detect -DeltaV.


Cheers, T i m

My (very old) charger from jessops (remember them?)
Charges AAs @ 150mA and AAAs @ 50mA singles or pairs x 2
PP3 @ 16mA single or pair
Max Charging time 15 hrs by Timer Control.

More is not always better.

15 hours! Impatient kids today can buy a 15 minute NIMH charger.

On Fri, 20 Nov 2020 14:19:41 +0000, bert wrote:

snip

My (very old) charger from jessops (remember them?)

I do. My Dad used to use them quite a lot.

Charges AAs @ 150mA and AAAs @ 50mA singles or pairs x 2

NiMh and Nicad?

PP3 @ 16mA single or pair

Ok.

Max Charging time 15 hrs by Timer Control.

Yeah, that's the thing, if you drop the current down you can safely
charge for a fixed time with little chance of overcharge and from the
link Pamela provided, might be safer than trying to detect the -dV

More is not always better.

Oh indeed.

The first electric RC cars we raced at Ally Pally came with a wire
wound resistor fixed to a small ally plate to limit the charge current
to the 4 x SubC 1.2Ah Nicads. Inevitably someone would 'forget' they
had left their batteries on charge and they would overheat, split
their cases, melt the plastic / ABS top and bottom trays they sat in
before one cell would explode. ;-(

So, I got a folded ally project case, fitted the resistor inside and a
clockwork timer (with built in switch) on the top. Connect to a car
battery, connect the output to the RC car battery, twist the timer to
20 mins and I didn't have to worry I would 1) burn myself / melt
something with the resistor and 2) overcharge the batteries. ;-)

Cheers, T i m