Filter motor battery power to run my arduino as well

Hi guys.

Ive got a 12v 33ah battery and 2 * 12v 180watt motors that draw anything from 8 to 18amps

Now ive got this motor driver installed at the moment as a stand alone driver but drawing power from it to power my uno:

https://www.robotics.org.za/index.php?route=product/product&path=303_189&product_id=729

But as you can see it can only handle 12amps, its working fine have tested it a lot but want to be sure it doesnt fail so im looking to get this driver:

https://www.robotics.org.za/index.php?route=product/product&path=303_189&product_id=249

But as you can see it does not have a pin to feed power to my arduino(or does it ?).

So i was wondering if theres not away to draw power from the battery and maybe add capacitors or something so if the motors draw to much current my arduino wont reset because they wont draw high current for a to long period?

Thanks
M.....

So i was wondering if theres not away to draw power from the battery and maybe add capacitors or something

Try a diode in series with the battery and Arduino, then put a capacitor (probably at least 100uF and maybe 1000uF) between the Arduino's power-input and ground.

The capacitor will charge-up to 12V (minus the 0.7V drop across the diode). If the battery power drops momentarily, the capacitor will continue to power the Arduino, and the diode prevents current from the capacitor from flowing back into the motor or battery.

Hey thanks DVDdoug im going to try that.

If the battery power drops momentarily, the capacitor will continue to power the Arduino

How long would you think it can carry it for and would adding more capacitors give it power longer, the arduino is running at +- 150mah?