Yamaha BIG BEAR YFM400NN Owner's Manual page 148

7. Remove the battery and charge it.
Store it in a dry place and recharge it
once a month. Do not store the battery
in an excessively warm or cold place
(less than 0 ˚C (30 ˚F) or more than
30 ˚C (90 ˚F)).
NOTE:
Make any necessary repairs before storing
the machine.
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