Wrappon 6900 Battery Trekker WT-4Handy Battery 6900 for Trekker WT 4 Toilet System If you have a battery, you can power the Wrappon even in places where power is not available. This lithium ion battery can be charged and used repeatedly. It takes 4 hours for one charge and a single charge can drive the Wrappon Trekker WT 4 Toilet System up to 90 times. When not used for your toilet system, it can also be used to power devices that require USB power supply. Output Voltage 14. 4V USB