Firstly, make sure you're not using too powerful a charger, or you'll damage the battery. A 2A charge (max) overnight will do the job. I should have mentioned that you should get yourself a cheapo meter. After the charge, disconnect the charger, and let the battery sit for ½hr to 1hr (to get rid of the surface charge.) Then test the battery voltage. You can do this at the point where the leads to the battery went, where you connect the charger. A good battery should read around 12.7v or higher. Keep us informed. Do this before you spend big $$$ on a new battery.
Remember, if you do need to buy a new battery, eventually, ignore whatever the salesman migh tell you about the battery being already charged, & give it the 2A overnight charge. If you don't do this, the new battery will have a very short life indeed.
