portable power supply

Any reviews on portable power supplies, like ipower watch. any other portable power supplies out there?

Had an ipower watch for about 2 months before it crapped out. Runs for 2 minutes then shuts off.

Any other experiences out there?

Someone informed time ago about the Red Dot batteries... Not completely like the watch, which I heard it's a crap and the different connections to the tattoo machines give lots of power loss or cuts, but to me it sounds much better... Didn't tried it tough

Where can i find more information on the red dot batteries?

I just found this site, called Trinity power supply.