Don't use that battery. Please. If you don't know what it is and how old it is, you are venturing into those shark-infested waters.
I think I recall that it's hard for you to get gear and whatnot? Well you should be able to import batteries from a reputable manufacturer unless where ever you are is so rabidly anti-vaping that this would be a problem. Battery distributors worth their salt though these days usually contain a "don't use in vaping" warning, so it would be hard to argue that it's "vape equipment." (It's more of a legal covering of butts, which you may not find with the rewraps and batteries you shouldn't use in vaping, in fact by now if I DIDN'T see that warning, I would be worried.)
If you cannot import, you are going to have to find a way to get your hands on some reputable batteries, or (worst case) find an internal battery mod that you KNOW is new. Either would be preferable than the situation you have going on now.... Used, unknown batteries are not safe as you have NO CLUE as to what a safe wattage range and whatnot would be. Sorry to be a downer, but batteries is really one of the MAIN areas where you really need to do so correctly. I'm sorry to hear about your problem, but it is best going to be remedied by getting new batteries. I'd check the "recommended" vendors (it's at the bottom of Mooch's battery chart) and see if any will ship to your location. If not, you are going to have to get creative about finding some, but checking out the chart should at least give you some idea of what a reputable battery should look like and then you can go from there....
Anna