No, the markings on the battery are not moisture indicators. Likely the the 7230 doesn't have a moisture indicator. If the battery is bad, you'll need to replace the battery. Not sure just how to know that though without having another battery to try. If the battery is good the only thing you can try is the following: What to do next if Jl Cmder will not connect and wipe - BlackBerryFAQ
You'll need the OS for the 7230 installed on your PC along with Desktop Manager. You can get it from T-Mobile
If none of this works, I'd say time to get a newer device. The 7230 is a pretty old device anyway.