The cells in lead batteries are about 2.1v or 2v nominal, so 12v batteries have 6 cells. If your charger only does 5 cells then it can't charge that battery.
I don't know exactly what the manufacturer of that battery says, or if there are set charging rules with lead batteries, but don't charge it at 2.6 amps, it's probably a bit much. I think people charge the 7ah batteries at .7 amps or less than 1 amp. So I'd probably charge that battery at around .5amps or no more than 1 amp. I suppose you could e-mail Power Sonic and ask them what the safe charge rate is.
http://www.power-sonic.com/index.php?id=29 Your battery doesn't come up when you search the part number.
I'd don't really know what you could use it for though. Maybe a tx pack
