Hi folks. I have owned an XSP for a while now. However, I have been so busy with work and other things that I have not even taken any of it out of the case for about 3 months. Today I finally had some time and opened everything up and decided to get it all ready to use a little since it's 80 degrees out and sunny here in northern California. I have four batteries. Each of them, before any charging, showed one blinking light when I took it out of the case. The first three seem to have charged up nicely and when I turn them on, they show four static lights on. Haven't checked voltages or anything more detailed yet but upon initial examination they seem fine. The fourth battery also showed 1 blinking light prior to any connection to the charger. However, when I put it on the charger, the lights cycled one time like they were going to start charging the battery and then all lights went out. I have tried doing this several times and the result is the same each time, one cycle of the lights and then no lights at all. With no indicator lights I don't know if the charger is doing anything with this battery or not. Can a battery be so low on power that it won't even light up the lights until it's charged for a while? I didn't want to test that theory without asking in the forum first since if I have a battery gone bad I don't know if leaving it on the charger for very long would be a very smart thing to do (I obviously know the answer to that; rhetorical question). What do you guys way smarter than me think I should do; leave it on the charger for a while, or presume it's gone bad? Thanks, Rob P.S. I should add that when I leave it on the charger for 5 minutes or so, it is not getting hot, bulging, or anything like that. It's just sitting there like it's not really a battery LOL. UPDATE: It appears to be ok now. I think it was literally so low that the lights wouldn't light. I left it on the charger for about 20 minutes and then turned it on. Instead of only showing one blinking light it showed one solid light and one blinking light. Once I put it back on the charger again the lights started blinking again just like all the other batteries while charging. So I guess in the end I just let the battery get very low from lack of use. I couldn't help it. Been too busy to even take the stuff out of the case.