when to recharge li-ions?
- Thread starter KAP
- Start date
Marduke
Flashaholic
TooManyGizmos
Flashlight Enthusiast
.
As I recall , I think the ruling was at 3.65 volts .
I think as they get lower than that it causes damage and lowers their cycle life.
Definately charge before they reach 3.50 volts IMO .
Stop charging between 4.15 and 4.20 volts , dont exceed 4.20v.
.
As I recall , I think the ruling was at 3.65 volts .
I think as they get lower than that it causes damage and lowers their cycle life.
Definately charge before they reach 3.50 volts IMO .
Stop charging between 4.15 and 4.20 volts , dont exceed 4.20v.
.
TranceAddict
Newly Enlightened
charge it before no load voltage drops below 3.6v,
all laptop, cellphone...use this setting, it cant be wrong
all laptop, cellphone...use this setting, it cant be wrong
DM51
Flashaholic
Li-Ion cells should be charged before they run down to empty. You can top them up as often as you like, even if you have only used them for a few minutes.
Here is a useful table illustrating Li-Ion cell capacity, which has been reproduced here several times:
4.2 volts 100%
4.1 about 90%
4.0 about 80%
3.9 about 60%
3.8 about 40%
3.7 about 20%
3.6 empty for practical purposes
<3.5 = over-discharged
If you do discharge them to empty, the quicker they are put back on the charger the better.
Don't store Li-ion cells either 100% full or empty (although empty is worse). The best long-term storage voltage for them is ~50% (3.8V-3.9V)
Here is a useful table illustrating Li-Ion cell capacity, which has been reproduced here several times:
4.2 volts 100%
4.1 about 90%
4.0 about 80%
3.9 about 60%
3.8 about 40%
3.7 about 20%
3.6 empty for practical purposes
<3.5 = over-discharged
If you do discharge them to empty, the quicker they are put back on the charger the better.
Don't store Li-ion cells either 100% full or empty (although empty is worse). The best long-term storage voltage for them is ~50% (3.8V-3.9V)
javajoe
Newly Enlightened
How should people who do not have a way to measure the voltage of their li-on cells (like me) determine when to charge/how to store. I have a pair of rcr123a batteries and a light with a runtime of ~50 minutes. So if I replace the battery once a week and store the spare fully charged will I be doing something wrong?
At what voltage does a protected cell cut off while in use in a flashlight?
At what voltage does a protected cell cut off while in use in a flashlight?
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Marduke
Flashaholic
If you have no means by which to monitor your cells, you should NOT be using them in the first place... :whistle:
javajoe
Newly Enlightened
OK I guess I saw that comming. could you please suggest some inexpensive options for monitoring tools?
Also, any comments on the second part of my post regarding when protected cells cut off?
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Marduke
Flashaholic
The undervoltage protection is specific to the cell, but ~2.75v-ish seems common. However, you should NOT be using this as a means of cutoff. Routinely doing so will damage the cell.
Harbor Freight has cheap DMM's, but they can be found nearly as cheap at a multitude of places.
javajoe
Newly Enlightened
so any inexpensive digital multimeter that measures to 00.0 should be good enough?
