Question about RCR123's

[blackfly]

Hello everyone. I have some AW RCR123 batteries. On more than one occasion I have accidentally run the batteries down to the point where their over discharge protection kicks in. Is this safe to do? I measured about 3.15 volts on my voltage meter & they seem to recharge ok. I know lithium ion batteries are not supposed to be discharged below a certain point. But since the batteries still have a voltage reading above 3 volts they should still be ok, right?. How reliable is the circuitry? Can I just use the batteries 'til they shut off since their protected?

 

[Mr Happy]

Hello everyone. I have some AW RCR123 batteries. On more than one occasion I have accidentally run the batteries down to the point where their over discharge protection kicks in. Is this safe to do? I measured about 3.15 volts on my voltage meter & they seem to recharge ok. I know lithium ion batteries are not supposed to be discharged below a certain point. But since the batteries still have a voltage reading above 3 volts they should still be ok, right?. How reliable is the circuitry? Can I just use the batteries 'til they shut off since their protected?

It is best to recharge them before the protection circuit kicks in. Relying on the protection circuit has two disadvantages:
1) It is a safety device only -- one day it might fail;
2) Repeatedly discharging the batteries to a low voltage may slightly shorten their life compared to recharging them sooner.

 

[BIGLOU]

blackfly,

What I do is ocassionally check the voltage depending on use. I keep it above 3.8V. I go by this chart:

4.2V-100%
4.1V-90%
4.0V-80%
3.9V-60%
3.8V-40%
3.7V-20%
3.6V-Empty
3.5V-Overdischarging

Keep above 3.8V. Storing at less tha 3.6V causes damage.
I hope this helps.

 

[campingnut]

Does this advise also hold true for 14500's?

 

[blackfly]

Thanks for your replies. I think I was letting the batteries get too low. I was trying to push them to 3.2 volts before recharging.

 

[phonoe]

Does this advise also hold true for 14500's?

Yes, I think this applies to most Li-ion 3.7 V.

 

[45/70]

All Li-Ion cells live longer if discharged to no lower than about 20% remaining capacity. This is about 3.70 volts rested, open circuit voltage. This can extend cell life considerably vs. discharging to 3.50 volts OC. Cells that are discharged to less than 3.50 Volts (again, rested OC voltage) frequently, are likely to have a very short cycle life.

It is also important to note that the protection circuit installed on manufacturers cells by third parties, is there to prevent catastrophic failure of the cell, when charging and discharging, not to remind the user that the cell needs to be recharged. This is also a major reason that the manufacturers of Li-Ion cells do not produce cells with protection circuits. The liability is too great a risk if the circuit were to be misused, or malfunction, in their opinion.

Dave