Power recommendations for a small robot

Hello,

As I might have mentioned ;), I'm starting out building a bot. I think I'm experiencing a problem with my LCD due to power limitations.

I'm using a 9V PP3 at the moment (I know, I know, evil, but it's what came with the Arduino kit) and a set of four 1.5v random AA batteries I already had.

The stuff I'm running off this will be:

2x little motors, rated at 6V but happy up to 9V, 40mA free-running
1x little servo, rated at 6A, not sure about the current
1x PING))), rated at 5V, 20mA
1x Graphical LCD with serial backpack, rated 6V-7V, 220mA

I'm still struggling with battery selection, I'm still in the "if it fits in my remote it's okay" stage, not really had to think about mAh and clever stuff before :slight_smile:

Thanks.

You mentioned "mAh" - that's useful measure.
You need to decide how long you want your robot to run without changing or recharging the batteries.
So, tell us what the average current consumption is likely to be.

A good question... I'll have to hook my meter up when I get home and see what I get.

Been away for the weekend (but the food-fair was worth it ;)) so not had a chance to get power readings yet, but assuming I go the rechargeable-batteries route, am I correct in thinking that NiMH ones are a good bet? They seem to have favourable mAh ratings compared to other types of battery.

Thanks