Perko 8503DP Battery Selector Switch, No Key Lock

The Perko 8503DP Medium Duty Battery Selector Switch is rated 250A continuous and 360A intermittent, in a 5-1/4-inch housing without a key lock.

No key lock is the distinction from the locking versions in the same range, and it is a deliberate choice rather than a lesser specification. A key lock stops the switch being turned by anyone without the key, which matters on a moored boat. It also means the key has to be aboard and findable in an emergency, which is the argument against it.

Five and a quarter inches is the standard face diameter, against the 4-inch compact versions. The larger face gives a bigger knob and clearer position marking, which is worth having on a switch operated in a dark locker.

A 5/16-inch terminal stud takes heavy battery cable lugs, so the lug size needs matching before installation. Two hundred and fifty amps continuous with 360 intermittent for five minutes covers most starting and house-bank work, across 6 to 32 volt systems. Explore more battery switches.

• No key lock: a choice, not a lesser specification
• A lock stops unauthorized use, but the key must be findable
• 5-1/4 inch face, against the 4-inch compact versions
• Bigger knob and clearer marking in a dark locker