Polar Reserve will even work after PolarStorm has provided cool temperatures for your sleeper for the past 10 to 12 hours.
How can this be? Its simple. PolarStorm never deep cycles your battery. When your Lithium Iron Phosphate 4 (LiFePO4) battery is drawn down to 48 volts DC, PolarStorm will automatically shut off and wait to be recharged by your trucks alternator. It takes 10 to 12 hours of continuous operation for this to happen. The operating voltage for PolarStorm is from 53.6 volts DC to 48 volts DC. For each hour of PolarStorm operation, the voltage drops by about ½ of a volt. When the voltage drops to 48 volts, PolarStorm automatically shuts off. However, the LiFePO4 battery can be safely discharged down to 44 volts DC. That means that for the next 4 hours Polar Reserve will charge your batteries or run your truck. Typically, after 20 minutes of Polar Reserve, your house batteries will be recovered enough to start your truck.
In the winter time when you're not using PolarStorm for cooling, you will have reserve power for about 20 hours of driving, should your truck alternator fail.
PolarReserve draws about 13 amps per hour when it is charging at the maximum rate of 50 amps. As the battery bank that PolarReserve is charging becomes charged, the current draw lessens at a lineal rate down to 50 miliamps when the bank is charged.