Bombardier SeaDoo 1998 factory shop manual, Page 236Get this manual

Section 08 ELECTRICAL SYSTEM Subsection 03 (CHARGING SYSTEM)
Do not charge frozen batteryIf the battery charge is very low, the battery may freezeIf it is suspected to be frozen, keep it in heated area for about hours before charging!
WARNING

• ATV
• Jet Ski
• Outboard Motors
• Personal Watercraft
• Snowmobiles
• Stern Drives