Fossie Bear

I need your help please - Since a slow speed (30mph ish) spill on either diesel or black ice my battery doesn't want to hold its charge. A reading from a multimeter before charging gives 12.37volts, after charging 13.27, so that's encouraging. The spill might have just been a coincidence but had to have the bike recovered as it just wouldn't turnover - pardon the pun. The battery lasts a couple of pleasure or commuter trips and it needs recharging again Your ideas or thoughts appreciated. Fossie Bear