I have a 2s lipos and never run them below 6.8 volts. I usually charge them when I am done running. I don't remember how I left this battery but it has sat for about 10 days. I checked the voltage and it was 5.7. When I put it on the charger it jumped pretty fast (within 5 minutes to 6.4 or so.
Any thoughts on what could have happened?