Hi Tom,

I use 'Accuguard' for 12V SLA (Sealed Lead Acid) batteries.

try :

Accuguard

Excellent price/performance, short circuit proof, overload proof etc...

The batteries I use, as mentioned the 12V / 7-10Ah SLA :

try :

12V / 7-10Ah SLA Batteries

and/or :

http://www.ebay.com/itm/12V-7AH-12-Volt-7-Amp-Hour-UB1270-APC-RBC17-LS700-SLA-Sealed-Lead-Acid-Battery-/180925147763?pt=US_Rechargeable_Batteries&hash=item2a1ffaaa73

Long lasting power for a cheap price. You can also power the H-Bridge (you know, the famous L298 one) for DC motors up to 2Amps (continuous). Lots of cheap power.

Good luck,

PhG

thanks, i have custom 4x4 rock crawler as base(custom to climb up steps)so looking for best and light.

on robot ~dual motor rock crawler with m2 dig motor controller ~foscam ip camera maybe 2(with ir night vision) ~ez robot(trying to get wifi working so computer does not go on robot) ~and arm to open doors ~6 servos(at least) ~arduino ~maybe a wifi router

I am using what I thought was two twelve volt Jet-ski batteries. There were perfect. I hook them in parallel. But, I found out that they are exactly 11.9 vdc instead of 13.6 volts without a load. But, they work very well.

For my smaller robots, I use the 3800 and 4800 mah RC battery. NMiH.

They both have their own special charger for the batteries.