Need help with selecting the proper switch...

[George H260]

I bought a % of charge DC Voltmeter and would like to use it to read both battery banks (instead of buying two expensive meters!). I figure wiring the +/-leads from each battery to a switch then wiring the switch to the meter should do the trick. I assume the switch would have to be a DPDT (on-off-on) with 6 spades on the bottom. Wire one battery to one side, the other to the opposite side, the switch to the middle contacts, correct?Also, the meter requires an inline 1-Amp fuse on the + lead. Should I wire a fuse on the + lead from each battery to the switch, or is one fuse on the + lead from the switch to the meter sufficient? (Seems like it should be...) Thanks for your help!

 

[newly anonymous]

two fuses

just in case there's ever a short between the batteries and the meter. and don't forget that with a DPDT switch, the battery selected will be on the opposite side of where the toggle is thrown.

 

[George H260]

Thank you, John.

Will do.

 

[Phil Teter]

safer with 2

Boat/US has a New Mar percentage meter for $34.99. I would expect the neg connections to be common for the two batteries. Each battery neg should be connected to the boat grounding system. If this is true you only need to switch the pos terminal and connect the other meter terminal to the common neutral.

 

[George H260]

Good point, the batteries' negative posts...

are connected in series from a single ground source (the engine block) therefore, one negative wire running from either battery's negative post through the switch to the meter's negative terminal should do. To switch only the positive wires running through the switch, a SPDT switch (3 spade connectors in the back) is what I want?