SilverFox
Flashaholic
Children often forget to turn off their battery operated toys. Sometimes they will go
back to play with the same toy again, but often they just move on to the next
adventure.
I always recommend trying to train everyone, including children, in the proper use and
care of rechargeable batteries, but some are more receptive to the information than
others...
I like Eneloop cells. They do everything a rechargeable cell should do and seem to
handle a fair amount of abuse also. My toys, oops, I mean my grandchildren's toys
,
are all powered by Eneloop cells. Most of my cell testing has to do with performance,
but this time I ventured into the "dark side" - abuse testing.
From here on, the story gets a little abusive, so kids and sensitive people should
probably tune out... :devil:
Still with me...?
OK, how many times has it been mentioned that it is not the best practice to over
discharge cells? Yes, lots and lots is a very large number.
Still, I run into people that don't want to use excellent cells in their toys, or their
children's toys because they fear over discharging them, and ruining them.
I grabbed an Eneloop cell that I had purchased some 3 years ago and have been
abusing it by not using it.
I ran a discharge at 500 mA to see if there was anything left in it, and it came in at
1250 mAh on the C9000. Not too bad, about 64% capacity left after 3 years of storage,
and these cells weren't completely charged to start with. I believe they started at
around 75% of full charge.
The next step was to do a Break-In cycle. The cell came in at 1925 mAh.
I then put the cell in a light and drained it. I left it in the light overnight and over
discharged it. I then took a piece of foil and clamped the cell with the positive and
negative terminals in a direct short.
Two days later, I took the cell out of the clamp. The voltage rebounded to 0.1 volts.
Please note that I am working with a single cell and there is no opportunity for reverse
charge. If I can bring myself to do it... I may drag out another cell and repeat this
with a pair of cells.
At any rate the C9000 accepted the cell for charging without problems. I did another
Break-In cycle and the capacity came in at 1939 mAh.
Wow, a slight increase in capacity in spite of being discharged overnight and shorted
out for an additional two days.
I asked my grandchildren how long they would "loose" toys trying to figure out where in
the spectrum of things two or three days fit in. They assured me that most of their toys
would be played with in two or three days, but there may be some that could possibly
get "lost" and go a little longer. Mom nodded in agreement, but thought that a week or
two may be more realistic.
The next step was to once again drain the cell in the light overnight. I then shorted it
out with my clamp and foil set up and left it for 5 days.
When I removed the cell from the clamp, the voltage rebounded to 0.008 volts. Once
again the C9000 had no problems initiating a charge on the cell, however, once again I
ran a Break-In cycle on the cell. This time the capacity came in at 1943 mAh. Wow,
once again a slight increase in capacity.
The point of this exercise is that as long as the cell is not reverse charged, it seems to
handle over discharging with ease. At least with a high quality cell and with the cell
being totally shorted out for 5 days. Even in multicell applications, when Eneloop cells
are being used, they should be well balanced and there should only be a very remote
chance of cell reversal.
At any rate, if you go around and make sure the toys are shut off every 5 days, your
cells should survive.
There is more...
Anticipating that some parents have very busy schedules, and checking the status of
toys every 5 days would just be too much effort, I decided to do another test.
This time I discharged the cell in the light overnight, then shorted it out and clamped it
and this time I left it for 14 days.
When I removed the cell from the clamp the voltage rebounded slowly to 0.002 volts.
The C9000 had no problem recognizing it and I got an IR reading of 1.56. I ran
another Break-In cycle and the capacity came in at 1946 mAh. Another slight increase.
I can't believe that shorting a NiMh cell is good for it, but it looks like it isn't too hard on
it either. Wondering if the low self discharge capability was effected I let the cell sit for
a little over 2 weeks, then ran a 500 mA discharge on it. It came in at 1746 mAh.
Many people save their crap cells to use with toys. The justification is that the cells are
already crap so over discharging won't hurt them too much. I think that care for toys
should be part of the experience of playing with powered toys, and I also think that
crap cells should be recycled. Quality cells work much better in toys, and I think that
children begin to understand that their toys last much longer because of the quality
cells that are being used.
This round of abuse testing seems to indicate that even if the toy is left on and
forgotten for two weeks the cell still has a chance to recover.
In the spirit of full disclosure... I will mention that this round of testing was sponsored
by the influential chairman of "CSOCC."
That would be ME :devil:
Tom
Chairman of the Coalition to Stop Out Crap Cells (CSOCC)
back to play with the same toy again, but often they just move on to the next
adventure.
I always recommend trying to train everyone, including children, in the proper use and
care of rechargeable batteries, but some are more receptive to the information than
others...
I like Eneloop cells. They do everything a rechargeable cell should do and seem to
handle a fair amount of abuse also. My toys, oops, I mean my grandchildren's toys
, are all powered by Eneloop cells. Most of my cell testing has to do with performance,
but this time I ventured into the "dark side" - abuse testing.
From here on, the story gets a little abusive, so kids and sensitive people should
probably tune out... :devil:
Still with me...?
OK, how many times has it been mentioned that it is not the best practice to over
discharge cells? Yes, lots and lots is a very large number.
Still, I run into people that don't want to use excellent cells in their toys, or their
children's toys because they fear over discharging them, and ruining them.
I grabbed an Eneloop cell that I had purchased some 3 years ago and have been
abusing it by not using it.
I ran a discharge at 500 mA to see if there was anything left in it, and it came in at
1250 mAh on the C9000. Not too bad, about 64% capacity left after 3 years of storage,
and these cells weren't completely charged to start with. I believe they started at
around 75% of full charge.
The next step was to do a Break-In cycle. The cell came in at 1925 mAh.
I then put the cell in a light and drained it. I left it in the light overnight and over
discharged it. I then took a piece of foil and clamped the cell with the positive and
negative terminals in a direct short.
Two days later, I took the cell out of the clamp. The voltage rebounded to 0.1 volts.
Please note that I am working with a single cell and there is no opportunity for reverse
charge. If I can bring myself to do it... I may drag out another cell and repeat this
with a pair of cells.
At any rate the C9000 accepted the cell for charging without problems. I did another
Break-In cycle and the capacity came in at 1939 mAh.
Wow, a slight increase in capacity in spite of being discharged overnight and shorted
out for an additional two days.
I asked my grandchildren how long they would "loose" toys trying to figure out where in
the spectrum of things two or three days fit in. They assured me that most of their toys
would be played with in two or three days, but there may be some that could possibly
get "lost" and go a little longer. Mom nodded in agreement, but thought that a week or
two may be more realistic.
The next step was to once again drain the cell in the light overnight. I then shorted it
out with my clamp and foil set up and left it for 5 days.
When I removed the cell from the clamp, the voltage rebounded to 0.008 volts. Once
again the C9000 had no problems initiating a charge on the cell, however, once again I
ran a Break-In cycle on the cell. This time the capacity came in at 1943 mAh. Wow,
once again a slight increase in capacity.
The point of this exercise is that as long as the cell is not reverse charged, it seems to
handle over discharging with ease. At least with a high quality cell and with the cell
being totally shorted out for 5 days. Even in multicell applications, when Eneloop cells
are being used, they should be well balanced and there should only be a very remote
chance of cell reversal.
At any rate, if you go around and make sure the toys are shut off every 5 days, your
cells should survive.
There is more...
Anticipating that some parents have very busy schedules, and checking the status of
toys every 5 days would just be too much effort, I decided to do another test.
This time I discharged the cell in the light overnight, then shorted it out and clamped it
and this time I left it for 14 days.
When I removed the cell from the clamp the voltage rebounded slowly to 0.002 volts.
The C9000 had no problem recognizing it and I got an IR reading of 1.56. I ran
another Break-In cycle and the capacity came in at 1946 mAh. Another slight increase.
I can't believe that shorting a NiMh cell is good for it, but it looks like it isn't too hard on
it either. Wondering if the low self discharge capability was effected I let the cell sit for
a little over 2 weeks, then ran a 500 mA discharge on it. It came in at 1746 mAh.
Many people save their crap cells to use with toys. The justification is that the cells are
already crap so over discharging won't hurt them too much. I think that care for toys
should be part of the experience of playing with powered toys, and I also think that
crap cells should be recycled. Quality cells work much better in toys, and I think that
children begin to understand that their toys last much longer because of the quality
cells that are being used.
This round of abuse testing seems to indicate that even if the toy is left on and
forgotten for two weeks the cell still has a chance to recover.
In the spirit of full disclosure... I will mention that this round of testing was sponsored
by the influential chairman of "CSOCC."
That would be ME :devil:
Tom
Chairman of the Coalition to Stop Out Crap Cells (CSOCC)
