70 Amp Progressive Dynamics Inteli-Power 9200 Series Converters with built-in Charge Wizard will recharge your RV’s battery to 90 percent in 2-3 hours. Many converters only have one charging mode, 13.6 volts, which can result in battery boil-off. The 9200 Series converters have four charging modes: BOOST (14.4 volts), NORMAL (13.6 volts), STORAGE (13.2 Volts) and DESULFATION (13.2 volts with a 15 minute 14.4-volt burst every 21 hours). Boost Mode: Rapidly brings RV battery up to 90 percent of full charge. Normal Mode: Safely completes the charge or maintains the charge. Storage Mode: Maintains charge with minimal gassing or water loss during periods of non-use or storage.