Avoiding a Voltage Spike With a 1-2 Battery Switch?

Question:

On my sailboat, I have a dedicated start battery and a (2) battery house bank. The start battery is on switch 1 and house on switch 2. If I need to motor for an extended period, how do I shift from my start battery to my house bank without risking a voltage spike as I move the switch to spot 1 to 2? - John

Answer:

Great question John, if your battery source selector switch is in good working, it’s got a make-before-break feature. In other words, when going from battery 1 to “both or all or combine” to battery 2, the switch is always connected to a battery even as it changes the state of the battery switch.