Feature:  Advanced MPPT maximum p0wer point tracking technology, the tracking efficiency is no less than 99.5%.  High quality components are used to improve the system performance, and the maximum conversion efficiency can reach97%.  Super fast maximum power tracking speed while ensuring tracking efficiency.  Accurate identification and tracking of the maximum p0wer point of multi-wave peak.  Reliable maximum input power of pv array to ensure the safety of equipment.  Wide pv array maximum p0wer point operating voltage range.  12/24v automatic voltage identification.  The LCD is designed to dynamically display the operation data and working status of the equipment.  Various load control modes: general mode, light control mode, dual time mode, pure charger mode and timing mode.  Seal, GEL, Flooded, LifePO4 and Li(NiCoMn)O2 charging process can be selected.  The function of battery temperature compensation.  Power statistics recording function.  Use the RS485methods to maximize the communication needs of different occasions.  Support PC monitor, external display unit and other peripherals, realize real-time data view and parameter setting function.     Specification:  Rated charge current:  POW-Keeper1220: 20A.  POW-Keeper1230: 30A. POW-Keeper1240: 40A.  System rated voltage: 12V/24V Auto work.  Voltage range of battery: 8-32V.  Max open voltage of PV module: 55V.  Battery type: User default, Sealed, Flooded, GEL, LiFePO4.  Equalized charging voltage: Maintenance-fee lead acid battery 14.6V, GEL: No: Lead acid flooded battery: 14.8V.  Absorption charging voltage:  Maintenance-fee lead acid battery 14.4V,GEL: 14.2; Lead acid flooded battery: 14.6V.  Floating charging voltage: Maintenance-fee lead acid battery, GEL, Lead acid flooded battery: 13.8V.  Low voltage re-connection (LVR): Maintenance-fee lead acid battery, GEL, Lead acid flooded battery: 12.6V.  Low voltage disconnection (LVD): Maintenance-fee lead acid battery, GEL, Lead acid flooded battery: 10.8V.  Static loss: <9.2mA 12V; <11.7mA 24V.  High voltage disconnection (HVD): 16V (24V x 2).  Duration of absorption charging: 2 Hours.  Light control voltage: 5V.  Charge loop voltage drop: <0.29V.  LCD Temperature: -20°C~+70°C.  Operating Temperature: -20°C-+55°C(To run at full rated current continuously).  Operating Temperature: -20°C-+55°C(To run at full rated current continuously).  Working humidity: <95% No condensation. Protection class: IP30.  Dimension (LxWxH) mm:  POW-Keeper1220: 123x178x48.  POW-Keeper1230: 135x202x55.  POW-Keeper1240: 150x220x67