That is a problem with lipo batteries if allowed to drain bellow a certain voltage they will not take a charge. I recommend charging them for storage.
I just went through this myself. i bought a replacement rechargable and the aa battery pack just incase.
13pro rmk162"CE2.5" 13.6 head pcv Dynoport pipe ypipe Mbrp can,extreme vents,MDS, airframes, WRP seat c3 beltdrive 8"led light 7"powder hounds, stage5 elka shocks,alt impact a arms- 162"CE2.5" T-nytro mcx, full mod only the plastic is stock.