Morningstar 6A 12V Sunsaver Charge Controller with low voltage disconnect.

If the battery falls below 11.5 (or 23.0) volts, the load is disconnected from the battery to protect against harmful deep discharges. A 2-second delay prevents load disconnects from transients. The load is automatically reconnected when the battery voltage recovers to 12.6 (or 25.2) volts.