I'm not really into Electrical stuff and this is the only place where I can ask this question and get a nice and described answer, basically I'm lookin for a good Charger/Discharger for a couple of 18650 3.7v Lithium batteries and I came across this:

AccuPower IQ338 Fast Charger and Analyzer Tester for Li-ion NiMH NICd Rechargeable Batteries

It looks good to me but I read that it apply a charge voltage of 4.13V, is this ok in my case?


closed as off-topic by PlasmaHH, PeterJ, Dave Tweed Dec 11 '17 at 13:44

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  • \$\begingroup\$ ya, it says it can handle 18650s. It applies a voltage of 4.13, so that a charge can flow back into the battery. Therefore you would expect something above 3.7v \$\endgroup\$ – Makoto Dec 11 '17 at 13:35

Yes, it is OK. The picture actually shows an 18650 cell being charged.

You might be confused by the 3.7 V and 4.13 V.

The fact is that the voltage of Li-Ion based cells (like 18650 cells) changes when it is charged and discharged.

3.7 V is sort of a "average" voltage for the cell when in use.

A reasonable low (empty) voltage for a Li-Ion based cells is 3.6 V

A reasonable high (fully charged) voltage for a Li-Ion based cells is 4.2 V

So the charger's 4.13 V is a good choice. Charging to a higher voltage (like 4.3 V) is possible but puts more stress on the cells so they wear out sooner. I think 4.13 V is a good compromise.

Learn more about this at Battery University.


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