How to check capacity with a hobby charger?

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peterloron
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How to check capacity with a hobby charger?

So I now have an Accucel 6 hobby charger. Seems to be working ok. What is the typical method used to determine capacity of cells? Do a full charge, and then a discharge cycle? What is the typical voltage folks discharge to for LiIo and LiPo cells?

Thanks.

-Pete

scaru
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Ok, first charge it up. I generally charge it at 1 amp, and make sure it is set to single cell. Then set it to discharge at 1 amp until 3 volts. Hit start and wait for it to finish. (I'm doing that right now)

DENGOH
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Accucel6 doesn’t let you set the cut off voltage for Lithium batteries. Only can set the cut off voltage for NiMH or NiCD.
You choose the right chemistry for the lithium batteries, it will set the right cut off voltage.
Yes, you need to do a full charge first. Then discharge let’s say at 500mA so that your cable connection doesn’t affect the capacity measurement too much. But it will be slow to discharge at 500mA. Choose a discharge current depends on your battery size and how good your cable connection is.

cool i'll see you when you get there

scaru
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DENGOH wrote:
Accucel6 doesn't let you set the cut off voltage for Lithium batteries. Only can set the cut off voltage for NiMH or NiCD. You choose the right chemistry for the lithium batteries, it will set the right cut off voltage. Yes, you need to do a full charge first. Then discharge let's say at 500mA so that your cable connection doesn't affect the capacity measurement too much. But it will be slow to discharge at 500mA. Choose a discharge current depends on your battery size and how good your cable connection is.

Well, it does but the minimum is 3 volts so you could set it to 3.5 if you wanted. Sad That is why when testing NCR18650 batteries you have to use nimh mode and set the terminatiojn voltage at 2.5 or 2.75. 

DENGOH
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scaru wrote:

DENGOH wrote:
Accucel6 doesn’t let you set the cut off voltage for Lithium batteries. Only can set the cut off voltage for NiMH or NiCD. You choose the right chemistry for the lithium batteries, it will set the right cut off voltage. Yes, you need to do a full charge first. Then discharge let’s say at 500mA so that your cable connection doesn’t affect the capacity measurement too much. But it will be slow to discharge at 500mA. Choose a discharge current depends on your battery size and how good your cable connection is.

Well, it does but the minimum is 3 volts so you could set it to 3.5 if you wanted. Sad That is why when testing NCR18650 batteries you have to use nimh mode and set the terminatiojn voltage at 2.5 or 2.75. 


Ya, I forgot about that. But I have never used it this way as discharging to 3V can already give good indication of the capacity.

cool i'll see you when you get there

peterloron
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Well, I checked out one of the cells I recently salvaged from a laptop pack (it’s an LG cell). A cycle only gives me about 400mAh. Strike one. Have a few dozen more to go through. Smile

scaru
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peterloron wrote:
Well, I checked out one of the cells I recently salvaged from a laptop pack (it's an LG cell). A cycle only gives me about 400mAh. Strike one. Have a few dozen more to go through. :-)

That sucks, in my experience the UR18650FMs hold up really well in laptop packs. I have a couple that do around 2400 mah. 

peterloron
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It’s floating at about 3.5V, but just doesn’t seem to have any oomph left. I have a bunch more to check, finges crossed.