The batteries FIRST gives us are gel cell batteries, the electrolyte is in the form of a non-spillable gel, not liquid hydrochloric acid like in car batteries. The acid in a battery is not so strong that it will dissolve things before your eyes like acid in the movies, but if you spill it on your hands and don't wash immediately and throughly it will start to burn and itch about as bad as a bad sunburn. And if you get it on your clothes, the next time you wash them there will be perfect holes the size of the drops of acid that got on them. So what you save in battery cost you will wind up paying in clothes or carpet cost. Car batteries also give off hydrogen gas when being charged, so it is not safe to charge them in a tightly sealed area where the gas could concentrate to explosive levels, I think this warning applies to gel cell batteries also.
About CCA (cold cranking amps) and Ah (amp*hours). Amp hours are a measure of a battery's capacity at a certain discharge rate, usually at 1/10 of the battery's capacity. For example, the battery you mentioned was labeled 2.2 Amp*hours. You would think this means the battery can deliver 2.2 Amps for 1 hour, it probably can't. But it probably can deliver 0.22 Amps for 10 hours. The slower you drain a battery the more you get out of it up to a point. A car battery is designed to deliver hundreds of amps for just a couple seconds. So, CCA is the current a battery can deliver for a very short time and it doesn't't tell you anything about the total capacity of a battery. Car batteries are also designed to be always charged up and if you discharge one completely it damages the battery. After all that, you can buy a better battery. Look in the yellow pages under batteries and tell them you want a gel cell, deep cycle battery, in my area they are sometimes called trolling motor batteries because people use them with small electric boat motors for fishing. Surplus catalogs like
www.allelectronics.com and
www.goldmine-elec.com sometimes have good deals on surplus batteries.