Charging LiIon with bench power supply?

[Dodge]

My Trustfire TR-001 charger just went

While I'm waiting for a new one to arrive, can I just use my bench power supply to charge LiIon cells?

It can be current and voltage limited, so I'm thinking if I set the current limit to 0.5C and the voltage to (say) 4.15v, can I just connect it up and leave it until the cell too registers 4.15v?

Or do LiIon chargers need to do something more clever than that?

(BTW, I have tried searching for the answer. If this is covered somewhere a direct link or suggested search terms would be helpful)

Thanks.

 

[Mr Happy]

I have seen someone demonstrate exactly this on a YouTube video. Unfortunately I can't find it right now.

It seems like using a bench power supply in that way provides just the CC/CV charging algorithm that is needed.

 

[chimo]

It can be done, BUT,

You should ensure that the pre-charge conditions are met and you should not leave them unattended or un-monitored.

I would recommend that you first read up on Li-ion battery charging from the "battery university". You can also get some good information from the semiconductor manufacturer's spec sheets for Li-ion charging ICs.

 

[rantanplan]

As chimo already said, you can do it, but you have to be careful ...

I´ve done it a couple of times and never had a problem. With using such a - proper adjusted - bench supply, you do more or less the same CC/CV-loading as chargers do, without the safety extras though.

I´ve done it the following way: Set the current limit to ~0.5C (short-circuit bench supply), connected a DMM parallel to the bench power supply for more precise voltage measurement, set voltage to 4.15V and then hooked up the battery. The accuracy of my bench power supply isn´t the best and a small drift occurs too, so I regulary check the voltage with the DMM, when the ConstantVoltage-Part of the loading is reached.

Risk is of course that you can easily shift the actuators of the supply by accident, or simply forget that you´ve done in the mean time some different work with it ... charging cells with a protection circuit will offer at least a small extra safety.

A good charger, which you can throw the battery in and forget it then, is still recommened. Problem is, that most of the cheap XY-fires (and rest) don´t do that either ...