[JSK]

Can anyone tell me what the black button is next to the ignition key switches on a gas powered 3100 Open? I'm thinking maybe a battery crossover switch.
Thanks, John

[ReelMagic]

Its the battery parallel switch (button). It brings the port and starboard batteries together to assist starting a motor

[JSK]

That's it. Battery parallel switch.
Thanks

[Chris Burkard]

It is the battery parallel switch and it connects the house and engine bank together for as long as you hold it. It does the same exact thing as the emergency interconnect, but on a temporary basis.

[justrollin]

The Battery parallel switch would help you in a spot where the port or starboard battery might be dead, in that case you could hold switch over to other side and still start your engines.

[JSK]

Thanks for the help. Anyone else running 2@6v per engine, total 4 starting batteries plus 1 8d house battery? Would this be a common set-up?

[Chris Burkard]

Just for reference:

Newer Tiaras only have two banks of batteries (One engine Bank and one house bank). The parallel switch actually connects the house and engine banks together.

Older tiaras had 3 banks if you will (Port engine, Stbd engine and house). The parallel switch in this set up would connect the port and starboard engine banks together.

[JSK]

Does anybody know why Tiara ran two 6v, in series, per engine as starting batteries and not a more common group 27 single marine battery as starting batteries? I think the group 27 would have a higher CCA and not Deep Cycle battery like the 6Volt. Since you don't really use the 6v deep cycle as intended for a starting battery. Thanks, John

[Chris Burkard]

JSK - What year is that Tiara 31? I have never heard of them running two 6V batteries in series for any battery bank. That sounds like an owner modification along the way. If I were you, I would switch it back to 12V batteries.

[Uhehner]

Two 6 volt batteries in series increases your Amp-hour capacity by the sum of the Ah of the two batteries. The sailboat crowd does this all the time. It's great if you have an inverter and want to leave the generator off. I have seen six of them in series and parallel wired for 12 volts. Capt. George