12v SLA Batteries?

Yea, the 2.6ah is the same as saying 2600mah, its the batt capacity. 1amp is 1000millamps or ma. If you have a pair, you could wire them in parallel and double the capacity to 5.2ah (5200mah) - would start longer.

I've seen something like these in UPS (un-interruptable power supply) for PCs or workstations where it costs money to lose work if power blinks or goes out. UPS gives you enough power to get your work saved and then shut down if power hasn't come back.