Ok, I'm on the other end of the state, too far to come help in person I'm afraid.<div style="padding-top: 5px; padding-right: 5px; padding-bottom: 5px; padding-left: 5px; margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">
Sounds like you ran the battery down too far. I'm assuming it is a lipo. Most chargers have built in safety programming, if the pack is at or less than 3 volts per cell, the charger will not attempt to charge them because there is a danger of overheating. You can sometimes get around this if your charger is also capable of charging Nicad or Nimh packs. You can set the charger for Nimh and charge the pack just long enough to get each cell above 3 volts. But you do not want to leave the pack on to fully charge with out setting the charger back to Lipo. Things can go BOOM if you forget this.

If your charger does not have a Nimh or Nicad setting, there is another way to rescue the pack. I'll help with that latter if it becomes necessary.

You could also have knocked a wire loose in the crash, You need to check your main leads and see what voltage you have, If you are getting 8 to 9 volts, then all the cells are probably ok, but just got run down a little low. But if your reading on the main leads is less than 8 volts, then you need to check each cell individually to see where we are, this is done by checking each pair of pins on the balance plug. If you have a three cell pack, the balance plug has four wires. They are usually Red, Blue, Yellow, and Black, in that order. Black and Yellow are one cell, with Yellow being positive (+) and Black is negative (-), Blue and Yellow are the center cell, with Blue being positve and Yellow is negative, Red and Blue are the last cell, with Red being positive and Blue being negative. Check each of these cells in this manner and write down the voltage readings.
If you have a loose wire, you will get no reading on one cell.

Most of the time what I find is the center cell gets pulled lower than the other two, as long as you are reading one volt or more on each cell, there is a chance of saving it.</div>