How do I charge batteries using a standard bench power supply?

Question

I would like to charge a pair of 3.7V, 1500mAh Li-ion cells but I do not have a charger for them. I would like to use a normal power supply to chrage them I just dont know what voltage and current i should put across and through the cells and for how long I charge them. Also I am not even sure if they are charged (I assume not because they are brand new) is there an easy way to check this? Failing an answer does anyone know what charger I could buy to do the job? Thanks

Answer 1

I would think (not being an expert) that you would charge one at 3.5v DC at 150mA for 10 hours or 2 for double that time........check voltage with a voltmeter at end of charge period.

Would have thought any small low voltage dc power supply would do the job.

Answer 2

Connect a small bulb (12 V or 24 V) in series with batteries adjust your power supply voltage to adjust the charging current.Usually charging current is 10% of the capacity of battery.For your case it should be 150mA.Charging time should be about 15 hours for the first time.You might need to readjust the current after a few minutes of charging due to increase in battery voltage.
you can connect more batteries in series.Charging time is the same so long as current is adjusted to 10%.

Answer 3

you need to apply a slightly higher charging voltage usually 10% higher, the voltage is the only thing you can control , the current will vary depending on how discharged the battery is ,the initial current will decrease as the battery charges, you could limit the current but there is really no need.
when the battery is charged it will draw very little current.
You can check to see if the battery is fully charged by using a voltmeter.

Answer 4

Any lithium ion charger from model shops. Lithium cells are very dangerous to charge and do explode if you put too much current into them or get them too hot. Don't even try with a bench power supply.

Answer 5

You need to know what the recommended charging current is and then limit the output of your power supply to give this current.

The voltage is irrelevent as long as the current is correct.

Answer 6

to develop PSU from commonly used 11V into 14V is basically about no longer attainable. except you may get carry of the circuit diagram of PSU and also you know very well the position to modify the foremost aspects (like oscillating transformer) or including aspects. shop in ideas, PSU is made from switching mode means provide it is truly complicated evaluate to the commonly used straightforward one.