Charging NiMh batteries when not completely discharged

[AK]

The aaa alkaline batteries went out on my tv remote.

I decided to use my NiMh UBL aaa batteries. 1100 mAh.

They are currently showing 1.31 volts.

And they work ok in the remote as is.

My charger is the manual type.

It charges that type at 150 mA.

I want them fully charged since they are 1.2 volts versus 1.50 for the alkaline.

I would like to know how much longer to charge them.

Thanks,
Andy

 

[Phil Allison]

AK wrote:

The aaa alkaline batteries went out on my tv remote.

I decided to use my NiMh UBL aaa batteries. 1100 mAh.

They are currently showing 1.31 volts.

And they work ok in the remote as is.

My charger is the manual type.

It charges that type at 150 mA.

I want them fully charged since they are 1.2 volts versus 1.50 for the alkaline.

I would like to know how much longer to charge them.

** The correct procedure is to discharge the cells fully and then apply a full recharge cycle - 8 hours in your case.

If you must recharge partly discharged cells, then it takes whatever time needed until their temperate just starts to rise. Constant monitoring by you is needed.



.... Phil

 

[AK]

On Thursday, June 13, 2019 at 7:28:44 PM UTC-5, Phil Allison wrote:

AK wrote:


The aaa alkaline batteries went out on my tv remote.

I decided to use my NiMh UBL aaa batteries. 1100 mAh.

They are currently showing 1.31 volts.

And they work ok in the remote as is.

My charger is the manual type.

It charges that type at 150 mA.

I want them fully charged since they are 1.2 volts versus 1.50 for the alkaline.

I would like to know how much longer to charge them.




** The correct procedure is to discharge the cells fully and then apply a full recharge cycle - 8 hours in your case.

If you must recharge partly discharged cells, then it takes whatever time needed until their temperate just starts to rise. Constant monitoring by you is needed.



... Phil

I have no way of monitoring temp.

How do I fully discharge the cells manually?

Andy

 

[default]

On Thu, 13 Jun 2019 19:08:20 -0700 (PDT), AK
<scientist77017@gmail.com> wrote:

On Thursday, June 13, 2019 at 7:28:44 PM UTC-5, Phil Allison wrote:
AK wrote:


The aaa alkaline batteries went out on my tv remote.

I decided to use my NiMh UBL aaa batteries. 1100 mAh.

They are currently showing 1.31 volts.

And they work ok in the remote as is.

My charger is the manual type.

It charges that type at 150 mA.

I want them fully charged since they are 1.2 volts versus 1.50 for the alkaline.

I would like to know how much longer to charge them.




** The correct procedure is to discharge the cells fully and then apply a full recharge cycle - 8 hours in your case.

If you must recharge partly discharged cells, then it takes whatever time needed until their temperate just starts to rise. Constant monitoring by you is needed.



... Phil

I have no way of monitoring temp.

How do I fully discharge the cells manually?

Andy

If they are unused, it is best to charge low self-discharge NiMH every
nine to twelve months. Do NiMH batteries need to be completely
discharged before charging? No, NiMH batteries do not have a memory.
They can be charged without adverse effect at any point regardless of
their state of charge.

https://www.thomasdistributing.com/Battery-and-Charger-FAQs_ep_46-1.html

Get a quality charger that monitors each battery under charge
individually with an indicator for each cell to tell you when it is
recharged.

Monitoring temperature is over-kill IMO and not the best method. It
is too dependent on ambient temperatures, air flow, etc..

By all means get the batteries that are low self-discharge types.
(sold as "pre-charged")

Old Nickel Cadmium cells required discharging to get the full capacity
out of them.

 

[AK]

On Friday, June 14, 2019 at 4:52:06 AM UTC-5, default wrote:

On Thu, 13 Jun 2019 19:08:20 -0700 (PDT), AK
scientist77017@gmail.com> wrote:

On Thursday, June 13, 2019 at 7:28:44 PM UTC-5, Phil Allison wrote:
AK wrote:


The aaa alkaline batteries went out on my tv remote.

I decided to use my NiMh UBL aaa batteries. 1100 mAh.

They are currently showing 1.31 volts.

And they work ok in the remote as is.

My charger is the manual type.

It charges that type at 150 mA.

I want them fully charged since they are 1.2 volts versus 1.50 for the alkaline.

I would like to know how much longer to charge them.




** The correct procedure is to discharge the cells fully and then apply a full recharge cycle - 8 hours in your case.

If you must recharge partly discharged cells, then it takes whatever time needed until their temperate just starts to rise. Constant monitoring by you is needed.



... Phil

I have no way of monitoring temp.

How do I fully discharge the cells manually?

Andy

If they are unused, it is best to charge low self-discharge NiMH every
nine to twelve months. Do NiMH batteries need to be completely
discharged before charging? No, NiMH batteries do not have a memory.
They can be charged without adverse effect at any point regardless of
their state of charge.

https://www.thomasdistributing.com/Battery-and-Charger-FAQs_ep_46-1.html

Get a quality charger that monitors each battery under charge
individually with an indicator for each cell to tell you when it is
recharged.

Monitoring temperature is over-kill IMO and not the best method. It
is too dependent on ambient temperatures, air flow, etc..

By all means get the batteries that are low self-discharge types.
(sold as "pre-charged")

Old Nickel Cadmium cells required discharging to get the full capacity
out of them.

Thanks default.

My EBLs were low self discharge.

Andy

 

[Phil Allison]

default wrote:

Phil Allison wrote:


The aaa alkaline batteries went out on my tv remote.

I decided to use my NiMh UBL aaa batteries. 1100 mAh.

They are currently showing 1.31 volts.

And they work ok in the remote as is.

My charger is the manual type.

It charges that type at 150 mA.

I want them fully charged since they are 1.2 volts versus 1.50 for the alkaline.

I would like to know how much longer to charge them.




** The correct procedure is to discharge the cells fully and then apply a full recharge cycle - 8 hours in your case.

If you must recharge partly discharged cells, then it takes whatever time needed until their temperate just starts to rise. Constant monitoring by you is needed.



... Phil

I have no way of monitoring temp.

How do I fully discharge the cells manually?

Andy


...................................


If they are unused, it is best to charge low self-discharge NiMH every
nine to twelve months. Do NiMH batteries need to be completely
discharged before charging? No, NiMH batteries do not have a memory.
They can be charged without adverse effect at any point regardless of
their state of charge.

** Fraid you did not read the question, the OP wanted to know HOW LONG to charge his cells with his existing charger.

There is NO way to know that without first discharging them.

Get a quality charger that monitors each battery under charge

** An expensive and unnecessary option.

IOW - a wank.

Monitoring temperature is over-kill IMO and not the best method. It
is too dependent on ambient temperatures, air flow, etc..

** Utter bullshit.

Long as one has fingers on the ends of one's hand, a user can easily monitor a small temp rise that takes hours to happen.

Ambient and air flow have SFA to do with it.

Old Nickel Cadmium cells required discharging to get the full capacity
out of them.

** A well worn myth that applies only to cells made in the 1960s.

Bet not too many of them are still working...




.... Phil

 

[default]

On Fri, 14 Jun 2019 23:30:12 -0700 (PDT), Phil Allison
<pallison49@gmail.com> wrote:

default wrote:



Phil Allison wrote:


The aaa alkaline batteries went out on my tv remote.

I decided to use my NiMh UBL aaa batteries. 1100 mAh.

They are currently showing 1.31 volts.

And they work ok in the remote as is.

My charger is the manual type.

It charges that type at 150 mA.

I want them fully charged since they are 1.2 volts versus 1.50 for the alkaline.

I would like to know how much longer to charge them.




** The correct procedure is to discharge the cells fully and then apply a full recharge cycle - 8 hours in your case.

If you must recharge partly discharged cells, then it takes whatever time needed until their temperate just starts to rise. Constant monitoring by you is needed.



... Phil

I have no way of monitoring temp.

How do I fully discharge the cells manually?

Andy


..................................


If they are unused, it is best to charge low self-discharge NiMH every
nine to twelve months. Do NiMH batteries need to be completely
discharged before charging? No, NiMH batteries do not have a memory.
They can be charged without adverse effect at any point regardless of
their state of charge.



** Fraid you did not read the question, the OP wanted to know HOW LONG to charge his cells with his existing charger.

There is NO way to know that without first discharging them.

Mmm, and then he might use the recommended recharge time and get an
even charge in each, assuming of course, the batteries he's using are
the same capacity that was available when the charger was purchased,
and the batteries still retain their label capacity. Not having a
wealth of information on his charger I'd go with an intelligent
charger.

Those things with a transformer, diode, resistor for their
"technology" just don't cut it IMO; batteries cost too much and I
depend on them too much to skimp when it comes to a charger that will
far outlast the batteries and keep all my toys working.

Get a quality charger that monitors each battery under charge


** An expensive and unnecessary option.

Yup a smart chargers for (AAA-AA X4) costs about $10-20, while a cheap
one through a surplus or close-out outlet can be had for $2.

But given the cost of batteries, or how "mission critical" the
application is, or how much hassle one is willing to put up with to
save a buck or two, the relatively small difference in price
overwhelmingly favors the expense IMO.

IOW - a wank.



Monitoring temperature is over-kill IMO and not the best method. It
is too dependent on ambient temperatures, air flow, etc..


** Utter bullshit.

Long as one has fingers on the ends of one's hand, a user can easily monitor a small temp rise that takes hours to happen.

Ambient and air flow have SFA to do with it.

I'd tend to agree with you. Or would if I hadn't just finished a long
and careful study (observation) of some LED grow lights I'm using for
an "aero-garden" knock-off. The evidence I was seeing suggests the
mere orientation of the lights (vertical/horizontal), proximity to
things impeding air-flow, and ambient T, had a great deal to do with
peak temperatures. Turning on my whole-house fan, with no difference
in ambient and a "breeze" that was undetectable to me would result in
a 5 C change in temperature at the heatsink, ditto tilting the light
bars, moving them away from the housings etc..

I used a calibrated digital thermometer, not my fingers. (after my
fingers told me I might have a problem...)

I dunno about you, but I never argue with empirical results, no matter
what the theory, or my bias says.

Old Nickel Cadmium cells required discharging to get the full capacity
out of them.


** A well worn myth that applies only to cells made in the 1960s.

Bet not too many of them are still working...

"About 22% of portable rechargeable batteries sold in Japan in 2010
were NiMH" Wikipedia. So, with the exception of some small SLA
batteries that would imply that NiCads were still going strong.

Also from Wikipedia:
Work on NiMH batteries began at the Battelle-Geneva Research Center
following the technology's invention in 1967

Interest grew in the 1970s with the commercialisation of the
nickel–hydrogen battery for satellite applications.

In 1987, Willems and Buschow demonstrated a successful battery based
on this approach (using a mixture of La0.8Nd0.2Ni2.5Co2.4Si0.1), which
kept 84% of its charge capacity after 4000 charge–discharge cycles.

The first consumer-grade NiMH cells became commercially available in
1989.

In 1998, Ovonic Battery Co. improved the Ti–Ni alloy structure and
composition and patented its innovations.

"For 50 years, portable devices relied almost exclusively on
nickel-cadmium (NiCd). This generated a large amount of data, but in
the 1990s, nickel-metal-hydride (NiMH) took over the reign to solve
the toxicity problem of the otherwise robust NiCd. Many of the
characteristics of NiCd were transferred to the NiMH camp, offering a
quasi-replacement as these two systems are similar. Because of
environmental regulations, NiCd is limited to specialty applications
today." (from "battery university")

Actually the Chinese are still unloading some NiCads in things like
solar powered lights and such - I took some apart that I just bought.

You're a rude insufferable bastard most of the time, and
(infuriatingly) right most of the time; but this time you are WRONG.

... Phil

 

[default]

On Fri, 14 Jun 2019 20:02:22 -0700 (PDT), AK
<scientist77017@gmail.com> wrote:

On Friday, June 14, 2019 at 4:52:06 AM UTC-5, default wrote:
On Thu, 13 Jun 2019 19:08:20 -0700 (PDT), AK
scientist77017@gmail.com> wrote:

On Thursday, June 13, 2019 at 7:28:44 PM UTC-5, Phil Allison wrote:
AK wrote:


The aaa alkaline batteries went out on my tv remote.

I decided to use my NiMh UBL aaa batteries. 1100 mAh.

They are currently showing 1.31 volts.

And they work ok in the remote as is.

My charger is the manual type.

It charges that type at 150 mA.

I want them fully charged since they are 1.2 volts versus 1.50 for the alkaline.

I would like to know how much longer to charge them.




** The correct procedure is to discharge the cells fully and then apply a full recharge cycle - 8 hours in your case.

If you must recharge partly discharged cells, then it takes whatever time needed until their temperate just starts to rise. Constant monitoring by you is needed.



... Phil

I have no way of monitoring temp.

How do I fully discharge the cells manually?

Andy

If they are unused, it is best to charge low self-discharge NiMH every
nine to twelve months. Do NiMH batteries need to be completely
discharged before charging? No, NiMH batteries do not have a memory.
They can be charged without adverse effect at any point regardless of
their state of charge.

https://www.thomasdistributing.com/Battery-and-Charger-FAQs_ep_46-1.html

Get a quality charger that monitors each battery under charge
individually with an indicator for each cell to tell you when it is
recharged.

Monitoring temperature is over-kill IMO and not the best method. It
is too dependent on ambient temperatures, air flow, etc..

By all means get the batteries that are low self-discharge types.
(sold as "pre-charged")

Old Nickel Cadmium cells required discharging to get the full capacity
out of them.

Thanks default.

My EBLs were low self discharge.

Andy

EBL is what I've been buying and get good results with them. Eneloop
are excellent too but cost more. I just bought some Amazon branded
batteries to see if they are any good (but the price wasn't that much
better than EBL).

Awhile back, after getting frustrated with rechargeable AA
performance, I rigged a dummy load across a battery holder and bought
a few cheap quartz clocks to see which of the odd collection of
batteries I had on hand still could hold a decent charge. The clocks
stop working when the voltage gets down to ~.7V and records the hours
takes to get there.

 

[AK]

On Saturday, June 15, 2019 at 5:42:07 AM UTC-5, default wrote:

On Fri, 14 Jun 2019 20:02:22 -0700 (PDT), AK
scientist77017@gmail.com> wrote:

On Friday, June 14, 2019 at 4:52:06 AM UTC-5, default wrote:
On Thu, 13 Jun 2019 19:08:20 -0700 (PDT), AK
scientist77017@gmail.com> wrote:

On Thursday, June 13, 2019 at 7:28:44 PM UTC-5, Phil Allison wrote:
AK wrote:


The aaa alkaline batteries went out on my tv remote.

I decided to use my NiMh UBL aaa batteries. 1100 mAh.

They are currently showing 1.31 volts.

And they work ok in the remote as is.

My charger is the manual type.

It charges that type at 150 mA.

I want them fully charged since they are 1.2 volts versus 1.50 for the alkaline.

I would like to know how much longer to charge them.




** The correct procedure is to discharge the cells fully and then apply a full recharge cycle - 8 hours in your case.

If you must recharge partly discharged cells, then it takes whatever time needed until their temperate just starts to rise. Constant monitoring by you is needed.



... Phil

I have no way of monitoring temp.

How do I fully discharge the cells manually?

Andy

If they are unused, it is best to charge low self-discharge NiMH every
nine to twelve months. Do NiMH batteries need to be completely
discharged before charging? No, NiMH batteries do not have a memory.
They can be charged without adverse effect at any point regardless of
their state of charge.

https://www.thomasdistributing.com/Battery-and-Charger-FAQs_ep_46-1.html

Get a quality charger that monitors each battery under charge
individually with an indicator for each cell to tell you when it is
recharged.

Monitoring temperature is over-kill IMO and not the best method. It
is too dependent on ambient temperatures, air flow, etc..

By all means get the batteries that are low self-discharge types.
(sold as "pre-charged")

Old Nickel Cadmium cells required discharging to get the full capacity
out of them.

Thanks default.

My EBLs were low self discharge.

Andy

EBL is what I've been buying and get good results with them. Eneloop
are excellent too but cost more. I just bought some Amazon branded
batteries to see if they are any good (but the price wasn't that much
better than EBL).

Awhile back, after getting frustrated with rechargeable AA
performance, I rigged a dummy load across a battery holder and bought
a few cheap quartz clocks to see which of the odd collection of
batteries I had on hand still could hold a decent charge. The clocks
stop working when the voltage gets down to ~.7V and records the hours
takes to get there.

Interesting results.

Andy

 

[Tom Gardner]

On 15/06/19 11:42, default wrote:

On Fri, 14 Jun 2019 20:02:22 -0700 (PDT), AK
scientist77017@gmail.com> wrote:

On Friday, June 14, 2019 at 4:52:06 AM UTC-5, default wrote:
On Thu, 13 Jun 2019 19:08:20 -0700 (PDT), AK
scientist77017@gmail.com> wrote:

On Thursday, June 13, 2019 at 7:28:44 PM UTC-5, Phil Allison wrote:
AK wrote:


The aaa alkaline batteries went out on my tv remote.

I decided to use my NiMh UBL aaa batteries. 1100 mAh.

They are currently showing 1.31 volts.

And they work ok in the remote as is.

My charger is the manual type.

It charges that type at 150 mA.

I want them fully charged since they are 1.2 volts versus 1.50 for the alkaline.

I would like to know how much longer to charge them.




** The correct procedure is to discharge the cells fully and then apply a full recharge cycle - 8 hours in your case.

If you must recharge partly discharged cells, then it takes whatever time needed until their temperate just starts to rise. Constant monitoring by you is needed.



... Phil

I have no way of monitoring temp.

How do I fully discharge the cells manually?

Andy

If they are unused, it is best to charge low self-discharge NiMH every
nine to twelve months. Do NiMH batteries need to be completely
discharged before charging? No, NiMH batteries do not have a memory.
They can be charged without adverse effect at any point regardless of
their state of charge.

https://www.thomasdistributing.com/Battery-and-Charger-FAQs_ep_46-1.html

Get a quality charger that monitors each battery under charge
individually with an indicator for each cell to tell you when it is
recharged.

Monitoring temperature is over-kill IMO and not the best method. It
is too dependent on ambient temperatures, air flow, etc..

By all means get the batteries that are low self-discharge types.
(sold as "pre-charged")

Old Nickel Cadmium cells required discharging to get the full capacity
out of them.

Thanks default.

My EBLs were low self discharge.

Andy

EBL is what I've been buying and get good results with them. Eneloop
are excellent too but cost more. I just bought some Amazon branded
batteries to see if they are any good (but the price wasn't that much
better than EBL).

Awhile back, after getting frustrated with rechargeable AA
performance, I rigged a dummy load across a battery holder and bought
a few cheap quartz clocks to see which of the odd collection of
batteries I had on hand still could hold a decent charge. The clocks
stop working when the voltage gets down to ~.7V and records the hours
takes to get there.

I thought the subject was batteries, not cells.

When considering discharging, there is a very significant
difference between cells and batteries.

Fully discharging a cell with a resistor is relatively safe,
whereas fully discharging a battery that way *will* cause
the weakest cell to be reverse charged - and damaged.

 

[default]

On Sat, 15 Jun 2019 15:08:57 +0100, Tom Gardner
<spamjunk@blueyonder.co.uk> wrote:

On 15/06/19 11:42, default wrote:
On Fri, 14 Jun 2019 20:02:22 -0700 (PDT), AK
scientist77017@gmail.com> wrote:

On Friday, June 14, 2019 at 4:52:06 AM UTC-5, default wrote:
On Thu, 13 Jun 2019 19:08:20 -0700 (PDT), AK
scientist77017@gmail.com> wrote:

On Thursday, June 13, 2019 at 7:28:44 PM UTC-5, Phil Allison wrote:
AK wrote:


The aaa alkaline batteries went out on my tv remote.

I decided to use my NiMh UBL aaa batteries. 1100 mAh.

They are currently showing 1.31 volts.

And they work ok in the remote as is.

My charger is the manual type.

It charges that type at 150 mA.

I want them fully charged since they are 1.2 volts versus 1.50 for the alkaline.

I would like to know how much longer to charge them.




** The correct procedure is to discharge the cells fully and then apply a full recharge cycle - 8 hours in your case.

If you must recharge partly discharged cells, then it takes whatever time needed until their temperate just starts to rise. Constant monitoring by you is needed.



... Phil

I have no way of monitoring temp.

How do I fully discharge the cells manually?

Andy

If they are unused, it is best to charge low self-discharge NiMH every
nine to twelve months. Do NiMH batteries need to be completely
discharged before charging? No, NiMH batteries do not have a memory.
They can be charged without adverse effect at any point regardless of
their state of charge.

https://www.thomasdistributing.com/Battery-and-Charger-FAQs_ep_46-1.html

Get a quality charger that monitors each battery under charge
individually with an indicator for each cell to tell you when it is
recharged.

Monitoring temperature is over-kill IMO and not the best method. It
is too dependent on ambient temperatures, air flow, etc..

By all means get the batteries that are low self-discharge types.
(sold as "pre-charged")

Old Nickel Cadmium cells required discharging to get the full capacity
out of them.

Thanks default.

My EBLs were low self discharge.

Andy

EBL is what I've been buying and get good results with them. Eneloop
are excellent too but cost more. I just bought some Amazon branded
batteries to see if they are any good (but the price wasn't that much
better than EBL).

Awhile back, after getting frustrated with rechargeable AA
performance, I rigged a dummy load across a battery holder and bought
a few cheap quartz clocks to see which of the odd collection of
batteries I had on hand still could hold a decent charge. The clocks
stop working when the voltage gets down to ~.7V and records the hours
takes to get there.


I thought the subject was batteries, not cells.

When considering discharging, there is a very significant
difference between cells and batteries.

Fully discharging a cell with a resistor is relatively safe,
whereas fully discharging a battery that way *will* cause
the weakest cell to be reverse charged - and damaged.

Yeah, I conflate cell with battery, as do a lot of people.

AND that idea that the weakest cell suffers in a battery would also
hold true for the cheap chargers that charge cells by the pair. No
charging takes place unless there are two cells and then they are
charged in series - that seems like a good way to screw up batteries.

 

[Tom Gardner]

On 15/06/19 17:03, default wrote:

On Sat, 15 Jun 2019 15:08:57 +0100, Tom Gardner
spamjunk@blueyonder.co.uk> wrote:

On 15/06/19 11:42, default wrote:
On Fri, 14 Jun 2019 20:02:22 -0700 (PDT), AK
scientist77017@gmail.com> wrote:

On Friday, June 14, 2019 at 4:52:06 AM UTC-5, default wrote:
On Thu, 13 Jun 2019 19:08:20 -0700 (PDT), AK
scientist77017@gmail.com> wrote:

On Thursday, June 13, 2019 at 7:28:44 PM UTC-5, Phil Allison wrote:
AK wrote:


The aaa alkaline batteries went out on my tv remote.

I decided to use my NiMh UBL aaa batteries. 1100 mAh.

They are currently showing 1.31 volts.

And they work ok in the remote as is.

My charger is the manual type.

It charges that type at 150 mA.

I want them fully charged since they are 1.2 volts versus 1.50 for the alkaline.

I would like to know how much longer to charge them.




** The correct procedure is to discharge the cells fully and then apply a full recharge cycle - 8 hours in your case.

If you must recharge partly discharged cells, then it takes whatever time needed until their temperate just starts to rise. Constant monitoring by you is needed.



... Phil

I have no way of monitoring temp.

How do I fully discharge the cells manually?

Andy

If they are unused, it is best to charge low self-discharge NiMH every
nine to twelve months. Do NiMH batteries need to be completely
discharged before charging? No, NiMH batteries do not have a memory.
They can be charged without adverse effect at any point regardless of
their state of charge.

https://www.thomasdistributing.com/Battery-and-Charger-FAQs_ep_46-1.html

Get a quality charger that monitors each battery under charge
individually with an indicator for each cell to tell you when it is
recharged.

Monitoring temperature is over-kill IMO and not the best method. It
is too dependent on ambient temperatures, air flow, etc..

By all means get the batteries that are low self-discharge types.
(sold as "pre-charged")

Old Nickel Cadmium cells required discharging to get the full capacity
out of them.

Thanks default.

My EBLs were low self discharge.

Andy

EBL is what I've been buying and get good results with them. Eneloop
are excellent too but cost more. I just bought some Amazon branded
batteries to see if they are any good (but the price wasn't that much
better than EBL).

Awhile back, after getting frustrated with rechargeable AA
performance, I rigged a dummy load across a battery holder and bought
a few cheap quartz clocks to see which of the odd collection of
batteries I had on hand still could hold a decent charge. The clocks
stop working when the voltage gets down to ~.7V and records the hours
takes to get there.


I thought the subject was batteries, not cells.

When considering discharging, there is a very significant
difference between cells and batteries.

Fully discharging a cell with a resistor is relatively safe,
whereas fully discharging a battery that way *will* cause
the weakest cell to be reverse charged - and damaged.

Yeah, I conflate cell with battery, as do a lot of people.

AND that idea that the weakest cell suffers in a battery would also
hold true for the cheap chargers that charge cells by the pair. No
charging takes place unless there are two cells and then they are
charged in series - that seems like a good way to screw up batteries.

No, not necessarily.

Different cells *will* have different capacities
due to manufacturing tolerances. Discharging them
in series *will* lead to the cell with the smaller
capacity becoming reverse charged - and damaged.

Providing that the current/voltage is within the
specified trickle charging limits, if you charge
in series then one cell will become fully charged
before the other but overcharging shouldn't
damage it.

 

[Phil Allison]

Tom Gardner wrote:

........................

I thought the subject was batteries, not cells.

When considering discharging, there is a very significant
difference between cells and batteries.

Fully discharging a cell with a resistor is relatively safe,
whereas fully discharging a battery that way *will* cause
the weakest cell to be reverse charged - and damaged.

........................................

** When I was involved in electric car racing, the favourite way to discharge a 7.2V NiCd pak was to use a small, 12V lamp.

When the lamp dimmed, time was up. Immediate recharge prevented the harm that sometime happens to a reversed cell.

The risk is much greater with paks that contain many cells, the OP has a two cell pack so the risk is minimal.

.... Phil

 

[Tom Gardner]

On 15/06/19 23:54, Phil Allison wrote:

default the bulshitter wrote:


Phil Allison


The aaa alkaline batteries went out on my tv remote.

I decided to use my NiMh UBL aaa batteries. 1100 mAh.

They are currently showing 1.31 volts.

And they work ok in the remote as is.

My charger is the manual type.

It charges that type at 150 mA.

I want them fully charged since they are 1.2 volts versus 1.50 for the alkaline.

I would like to know how much longer to charge them.




** The correct procedure is to discharge the cells fully and then apply a full recharge cycle - 8 hours in your case.

If you must recharge partly discharged cells, then it takes whatever time needed until their temperate just starts to rise. Constant monitoring by you is needed.



... Phil

I have no way of monitoring temp.

How do I fully discharge the cells manually?

Andy


..................................


If they are unused, it is best to charge low self-discharge NiMH every
nine to twelve months. Do NiMH batteries need to be completely
discharged before charging? No, NiMH batteries do not have a memory.
They can be charged without adverse effect at any point regardless of
their state of charge.



** Fraid you did not read the question, the OP wanted to know HOW LONG to charge his cells with his existing charger.

There is NO way to know that without first discharging them.


Mmm, and then he might use the recommended recharge time and get an
even charge in each, assuming of course, the batteries he's using are
the same capacity that was available when the charger was purchased,
and the batteries still retain their label capacity.


** Results will be fine even if the cells are somewhat degraded.

If they are a whole lot degraded, then all bets are off of course.

You are clutching at straws and ignoring the OPs question.


Not having a
wealth of information on his charger I'd go with an intelligent
charger.


** Way outside the OPs question and argumentative.




Get a quality charger that monitors each battery under charge


** An expensive and unnecessary option.

Yup a smart chargers for (AAA-AA X4) costs about $10-20,


** Post a link, ones that monitor each cell and cut off automatically and reliably are not so cheap.



But given the cost of batteries, or how "mission critical" the
application is, or how much hassle one is willing to put up with to
save a buck or two, the relatively small difference in price
overwhelmingly favors the expense IMO.


** The OP already has the cells, they cost little and you are way over -interpreting the situation.


IOW - a wank.



Monitoring temperature is over-kill IMO and not the best method. It
is too dependent on ambient temperatures, air flow, etc..


** Utter bullshit.

Long as one has fingers on the ends of one's hand, a user can easily monitor a small temp rise that takes hours to happen.

Ambient and air flow have SFA to do with it.


I'd tend to agree with you.


** The why don't you shut up.


( snip pile of drivel )

I used a calibrated digital thermometer, not my fingers. (after my
fingers told me I might have a problem...)


** All TOTALLY irrelevant to merely detecting a small temp rise.

I dunno about you, but I never argue with empirical results,


** No, but I do sometimes argue with bullshitting idiots like you.




Old Nickel Cadmium cells required discharging to get the full capacity
out of them.


** A well worn myth that applies only to cells made in the 1960s.

Bet not too many of them are still working...

"About 22% of portable rechargeable batteries sold in Japan in 2010
were NiMH" Wikipedia. So, with the exception of some small SLA
batteries that would imply that NiCads were still going strong.


** What the fuck has that got to do with with "cells made in the 1960s" ???

Ignoring what has actually been posted is this fool's ONLY skill.



Actually the Chinese are still unloading some NiCads in things like
solar powered lights and such - I took some apart that I just bought.


** Ones I bought in the last 10 year all contained NiMH ells.

FYI:

NiCd cells have been banned from sale across the EU under RoHS rules for many years. Cadmium is a prohibited metal, even CdS photo cells are banned.

Except I bought some of these NiCds a year ago, from
a UK company.

https://www.batteriesplus.co.uk/acatalog/1.2V_NiCd_Sub_C_Rechargeable_Tagged_Batteries.html

You're a rude insufferable bastard most of the time, and
(infuriatingly) right most of the time; but this time you are WRONG.


** No, I am right this time too.

YOU are one rude, insufferable, pedantic, PITA old fool.

What goes around, comes around.

 

[Phil Allison]

Tom Gardner wrote:

Phil Allison:

** Ones I bought in the last 10 year all contained NiMH ells.

FYI:

NiCd cells have been banned from sale across the EU under RoHS rules for many years. Cadmium is a prohibited metal, even CdS photo cells are banned.

Except I bought some of these NiCds a year ago, from
a UK company.

https://www.batteriesplus.co.uk/acatalog/1.2V_NiCd_Sub_C_Rechargeable_Tagged_Batteries.html

** Allowed on sale for replacement purposes only, not permitted for new equipment. Even says so in the link.

You're a rude insufferable bastard most of the time, and
(infuriatingly) right most of the time; but this time you are WRONG.


** No, I am right this time too.

YOU are one rude, insufferable, pedantic, PITA old fool.

What goes around, comes around.

** Mindless clichĂŠ, from another bullshitter.



...... Phil

 

[Tom Gardner]

On 16/06/19 00:31, Phil Allison wrote:

Tom Gardner wrote:

Phil Allison:


** Ones I bought in the last 10 year all contained NiMH ells.

FYI:

NiCd cells have been banned from sale across the EU under RoHS rules for many years. Cadmium is a prohibited metal, even CdS photo cells are banned.

Except I bought some of these NiCds a year ago, from
a UK company.

https://www.batteriesplus.co.uk/acatalog/1.2V_NiCd_Sub_C_Rechargeable_Tagged_Batteries.html


** Allowed on sale for replacement purposes only, not permitted for new equipment. Even says so in the link.



You're a rude insufferable bastard most of the time, and
(infuriatingly) right most of the time; but this time you are WRONG.


** No, I am right this time too.

YOU are one rude, insufferable, pedantic, PITA old fool.

What goes around, comes around.


** Mindless clichĂŠ, from another bullshitter.

You are the one that retracted your statement above,
but only after its inaccuracy was pointed out.

 

[Phil Allison]

Tom Gardner pedant & bullshitter wrote:

Phil Allison:



NiCd cells have been banned from sale across the EU under RoHS rules for many years. Cadmium is a prohibited metal, even CdS photo cells are banned.

Except I bought some of these NiCds a year ago, from
a UK company.

https://www.batteriesplus.co.uk/acatalog/1.2V_NiCd_Sub_C_Rechargeable_Tagged_Batteries.html


** Allowed on sale for replacement purposes only, not permitted for new equipment. Even says so in the link.



You're a rude insufferable bastard most of the time, and
(infuriatingly) right most of the time; but this time you are WRONG.


** No, I am right this time too.

YOU are one rude, insufferable, pedantic, PITA old fool.

What goes around, comes around.


** Mindless clichĂŠ, from another bullshitter.

You are the one that retracted your statement above,

** I made NO retraction, what I posted was correct.

but only after its inaccuracy was pointed out.

** What a load of pedantic bullshit.



.... Phil

 

[Tom Gardner]

On 16/06/19 00:45, Phil Allison wrote:

Tom Gardner pedant & bullshitter wrote:


Phil Allison:



NiCd cells have been banned from sale across the EU under RoHS rules for many years. Cadmium is a prohibited metal, even CdS photo cells are banned.

Except I bought some of these NiCds a year ago, from
a UK company.

https://www.batteriesplus.co.uk/acatalog/1.2V_NiCd_Sub_C_Rechargeable_Tagged_Batteries.html


** Allowed on sale for replacement purposes only, not permitted for new equipment. Even says so in the link.



You're a rude insufferable bastard most of the time, and
(infuriatingly) right most of the time; but this time you are WRONG.


** No, I am right this time too.

YOU are one rude, insufferable, pedantic, PITA old fool.

What goes around, comes around.


** Mindless clichĂŠ, from another bullshitter.

You are the one that retracted your statement above,



** I made NO retraction, what I posted was correct.


but only after its inaccuracy was pointed out.


** What a load of pedantic bullshit.

I'm content to let others come to their own conclusion
about your comprehension skills, and about whether your
potty mouth helps or hinders your arguments.

 

[Phil Allison]

Tom Gardner Pedant & Bullshit Artist puked;

** Mindless clichĂŠ, from another bullshitter.

You are the one that retracted your statement above,



** I made NO retraction, what I posted was correct.


but only after its inaccuracy was pointed out.


** What a load of pedantic bullshit.


I'm content to let others come to their own conclusion
about your comprehension skills,

** LoL - thee are way beyond theirs.

and about whether your
potty mouth helps or hinders your arguments.

** Terms like " bullshitter" and " Pedant" are hardly foul language.

What they ARE in fact is concise, fair comment on some atrocious posts.

My original post to the OP contained no error and only good advice based on my many years of experience with rechargeable cells - however, having to defend such posts from ill informed comment from complete DICKHEADS like yourself and the anonymous defaulter is a disgrace.

Think about it sometime.


..... Phil

 

[whit3rd]

On Thursday, June 13, 2019 at 4:26:13 PM UTC-7, AK wrote:

The aaa alkaline batteries went out on my tv remote.

I decided to use my NiMh UBL aaa batteries. 1100 mAh.

They are currently showing 1.31 volts.

And they work ok in the remote as is.

Not a surprise; alkaline cells when fresh are 1.5V, but are useful down to about 1V.
NiCd and NiMH are 1.2 to 1.4V fresh-charged, useful down to about 1V.
Li nonrechargeables are 3.6V fresh, useful down to 3.0V (so can replace
a 4.5V alkaline clock battery, or two in series can replace a 9V which has 6 alkaline cells)

My charger is the manual type.

It charges that type at 150 mA.

I want them fully charged since they are 1.2 volts versus 1.50 for the alkaline.

Don't use rechargeables for best shelf life, but for best total life.

Mainly, your remote control is inert (it gets used in subsecond bursts when you press
a button). The self-discharge when not in use (and higher purchase price) make
rechargeables a questionable fit for that application.