batteries discharging

[rahulmagoo]

Hello,

I'm using four 4.2V batteries(Li-ion) to derive my motors(stepper motors)...I'm using L298 as my motor controller.
When i connect my batteries the motors run for few seconds then they stop as my batteries discharge very quickly...when i check the voltage ratting through multimeter..the voltage was changing(it was increasing).
Can any one please help me why is this happening.

Thanks

[pomprocker]

Do you have a large capacitor in series to regulate the voltage?

[rahulmagoo]

No I've not connected any cappacitor...the batteries are directly connected to the motor driver and this driver is driving the motors.

[ArcMan]

The increasing voltage you see may be due to the build-up of surface charge.  When a battery is at low charge and you remove the load from it, the voltage will increase for awhile.

[Trumpkin]

Check to see if you have a short.

[rahulmagoo]

No there is no short circuit...the circuit is absolutely fine.

[Admin]

to derive my motors(stepper motors)...I'm using L298 as my motor controller

The L298 doesn't work with stepper motors (well, at least without a complicated circuit). You need a stepper motor driver.

[rahulmagoo]

No the circuit is not complicated..I've copied the circuit as it is from the datasheet of L298..so there is no problem with my circuit...why L298 won't work with stepper motors?? what are the problems using L298?? can u suggest any other motor driver.

[Admin]

What schematic? I'm telling you, the L298 won't work with steppers!

And even more, the L298 datasheet says it requires at least 4.5V.

A 4.2V battery won't cut it.