12 Volt Digital 440 Amp Charge Controller with Divert Relay & LED Meter for Wind and Solar Dual microprocessor controlled for stability and accuracy On board relay isolates electronics from back voltage spikes from large 440 amp relay. This is important to get the longest life out of the electronics Multiple user changeable settings and trip points for many various system requirements and applications. Plug & Play: Long leads for easy termination to your 12 volt battery or battery bank Isolated Electronics Protection - Almost impossible to accidentally connect wind or solar directly to the circuit board