A low-voltage disconnect sits between your house battery and your loads, watches the voltage, and cuts the loads off before the battery gets drawn down far enough to hurt it. Then it reconnects on its own once the battery recovers.

Why it is worth $124

A deeply discharged lead-acid battery loses capacity permanently. A deeply discharged lithium battery can be damaged beyond recovery, and many BMS units will lock out entirely and need a specific recovery procedure. Either way you are looking at a few hundred to over a thousand dollars.

It happens in the most ordinary way: you leave a light on, or the fridge runs through two cloudy days while the vehicle is parked. The battery does not warn you. This device does the watching so you do not have to.

220 amps is the whole load side

At 220A this handles essentially everything on a typical 12V house circuit — fridge, lights, water pump, charging, a modest inverter. One device protects the lot rather than piecemeal protection per circuit.

Smart version

Bluetooth built in, so you set the cut-off and reconnect voltages in VictronConnect to match your battery chemistry rather than accepting a factory default. That matters: the right cut-off for an AGM bank is quite different from lithium, and getting it wrong means either nuisance disconnects or no real protection.

Specifications

• 220A continuous
• Operating voltage: 6–35V DC
• Bluetooth built in — VictronConnect app
• Programmable disconnect and reconnect thresholds
• Weight: 2.06 lb
• Manufacturer part number: BPR122022000

Important

A BatteryProtect goes on the load side, not between the alternator or charger and the battery. It is not a replacement for proper fusing. If you want a hand working out where it belongs in your system, send us a sketch of your wiring and we will mark it up.

⚠ WARNING: This product can expose you to chemicals which are known to the State of California to cause cancer, birth defects or other reproductive harm. For more information go to P65Warnings.ca.gov.