battery charger??

[chipdouglas]

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



thanks
michael

 

[mfo]

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



thanks
michael

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.

 

[spectral532]

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.

 

[bob808]

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?

 

[chipdouglas]

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

 

[spectral532]

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?

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.