I'm planning on running an LED lap counter and its wireless serial router on a UPS battery during meets. I've tested the display on the battery (a triplite 800w) and it lasts at least 4 hours before the level shows half. They both draw very little power. Are there any better solutions for a location without power? I've looked at various "power station" batteries but they all seem to use lead acid batteries so they can jump start cars. I can always swap it with the UPS I use on the timing system if it runs out but I'd rather not. A generator is not an option. Any suggestions?

I often use a 12v car battery in a case with a small inverter mounted on the top. Relatively easy to carry around, and you can make it as powerful as you want by using bigger batteries and bigger inverters. Either way there is a small charger that also mounts on the case for recharges.