I'm very pleased with my Kendrick batteries. I bought a small one many years ago, then a larger version when I got a bigger 'scope. But both still work fantastically well and each seems capable of driving the telescope all night. The problem I've had is with keeping my computer and CCD setup going, which requirer AC. (I'll never be able to run a laptop for hours on batteries, I have concluded.) Plugging into my Jeep's electrical system quickly drains the battery, unless I keep running the engine -- and that seems to be bad for the Jeep. I recently bought a gas-fueled generator that was on sale at Pep Boys and can't wait try it out in the field. The huge drawback is that the generator makes a lot of noise so I have to go off by myself to do astrophotography. -- Joe