The clever new VSR/Emergency Parallel box from our friends in New Zealand, BEP, is a great solution to an age-old boating problem. It covers your dual battery charging requirements and emergency parallel operation in one unit.

The unit’s VSR works to combine the boater’s start and house battery so both are being charged when sufficient voltage is available. That is, it will engage when the voltage on either start or house battery reaches 13.7 volts.

But, if the combined battery voltage drops below 13.0 volts and the engine is not running, after 5 seconds the contacts will open and stay open until the start or house battery voltage is greater than 13.7 volts.

So far, so good, but what makes the new unit from BEP especially useful is the addition of an emergency parallel override switch. It can be operated through a momentary button on the dash and will instigate a preset time of 10 minutes. Once this 10 minutes has passed, if the voltage is up high enough for the voltage sensitive relay to operate, it will stay engaged. If not, it will disengage.

Congratulations to BEP on a very clever and well executed design!