1989 Ski-Doo Repair Manual, Page 383Get this manual
Section 04 ELECTRICAL SYSTEM Sub-section 04 (BATTERY)
11Connect one end of vent tube to battery vent elbow and insert other end through bottom pan holeWARNING: Vent tube must be free and openA kinked or bent tube will restrict ventilation and create gas accumulation that might result in an explosion12 Coat terminals with petroleum jelly to prevent corrosion13Install protectors on exposed ends of retainer rods if applicable
Charging very flat or completely discharged battery:
Unless this procedure is properly followed, good battery may be needlessly replacedMeasure the voltage at the battery posts with an accu rate voltmeterIf it is below 10 vo lts, the battery wi ll accept cu rrent at very low rate, in term of miliamperes, because electrolyte is nearly pure water as explained aboveIt could be some time before the charging rate increasesSuch low current flow may not be detectable on some charger ammeters and the battery will seem not to accept any cha rgeExceptionn ally for this particular case, set the charger to high rate