I do have some experience rescuing these types of battery in other types of small device. Quite often the issue is that they have discharged so much that a low voltage cutout has kicked in isolating the battery from the charging circuit.
Sometimes the fix for this is to charge the battery to above the cut off voltage directly bypassing any internal charging and maintenance circuitry.
The below is assuming that this is a single cell Lipo or Liion battery:
The first thing to do is to find the + and - contacts of the
actual battery and verify that they have a voltage below 3v or so.
If comfortably above 3.2v then your battery isn’t the issue if it is lower then try and apply 4-5v directly to the battery, a cut USB cable can work as the power source. Only do this for a minute or so and stop immediately if you see the battery bulging or any smoke being emitted.
Remeasure the voltage and if it has risen above 3.2v then try and charge it normally. If it hasn’t risen then you could try repeating the above steps a couple of times but if the voltage doesn’t rise or the battery bulges then it’s dead.
A slightly more refined version of the above is to use a Liion charger rather than directly applied voltage. I use a disassembled e-cigarette charger for that purpose.