battery charger??

is it ok to use a ddl driver to make a battery charger if i set it 50ma or so?



thanks
michael

chipdouglas said:

is it ok to use a ddl driver to make a battery charger if i set it 50ma or so?



thanks
michael

Click to expand...

You also need to regulate the voltage also. Also, @ 50mA, it's going to take like 30 hours to charge the batteries depending on the capacity.

It depends on the the type of battery you are charging. You can use the DDL driver to trickle charge a NiMH battery. For Li-ions, you can use the LM317 in constant voltage mode to charge your batteries. Though you will need to limit the maximum current to around 0.7C.

I just bought 2xr123a rechargeables from AW, and I got a regulated voltage and current power supply. What shall I set it to so I can charge those Li-Ion batteries?

duelly noted on the amount of time requiered at 50 ma. thanks for the replies guys.

bob808 said:

I just bought 2xr123a rechargeables from AW, and I got a regulated voltage and current power supply. What shall I set it to so I can charge those Li-Ion batteries?

Click to expand...

Set the power supply to 4.2V and the current limit to 0.7C (0.7C means 0.7xCapacity. So if your cr123a has a capacity of 900mAh, limit the current to 900 x 0.7 = 630 mA). Additionally, you will need to stick around and monitor the current near the end of the charge. When the charge current drops to around ~0.05C you will need to disconnect the batteries to prevent trickle charging. After that your Li-ions should be at full charge.