The Pro Latch R is a versatile latching relay with 4 major operational modes. The benefit of using a latching style relay over a conventional relay is down to the efficiency of the relays. Conventional relays use up to as much as 0.5A to stay closed circuited. However, the latching relay does not use any current to stay closed. This is ideal for low harvest systems that include wind and solar. There are 4 major operational modes • Bidirectional Charging Mode. This mode allows activation of the Pro Latch R at both sides of the relay - ideal for normal between battery charging. Activation voltages are on at 13.3V and off at 13.0V. Battery Protection Mode. This mode allow the user to protect the battery from excessive charging and discharging. The on voltage is 12.0V and the off is 12.3V. Operational Mode 3. Engine Start Protect. This mode allow the user to protect the start battery from discharging beyond a point whereby they can no longer start the engine when cranking. The on voltage is 12.6V and the off is 12.4V. Operational Mode 4 Unidirectional Charging Mode. This mode allows for relay activation on one side of the relay only. Very similar to mode 1 without the bi-directionality. On at 13.3V and off at 13.0V.