Lights and Sound...can i keep it running?

[ShaneJ]

So Shane, the relay switches the earth to the main battery on when the ignition is on, and the second battery is live all the time? seems like a simple solution.

Warren

 

That's exactly how it works. This also allows you to only have a small main battery cause the only time it will ever be used is when cranking.

[Bren]

Just in case its not clear to anyone else reading this -
deep cycle batterys can be run down flat , and then recharged without a problem.
your standard battery will have a much shorter life if its run flat and recharged too many times.

you can also get dual battery controllers which make sure the main battery is fully charged
before the secondary one gets any juice.

[TheArchiTech]

Hi

Just wanting to clarify about where the relay actually goes. Does it connect stright up to the ignition wire.

Cheers

Phil

[ShaneJ]

The relay is switched on by the ignition.

[MaTTe]

Hey Shane, just saw this thread.
Whilst interested, I have a concern..
Wouldnt the relay need to be rated to the number of amps required to turn the motor over? for instance, if my motor requires 500A to turn over, the relay would then need to be rated to 500A so the earth can feed this amperage thru?

I have my dual battery setup in, with kill switch, but not driving the van for 2 weeks still killed the battery as there is obviously a leak to earth despite MOST things being on the dead side of the kill switch.

Disconnecting the earth would be the best bet..

[ShaneJ]

You are correct about the relay amperage but remember solinode relays will have a much higher peak current rating than what they are marked as. A 300 amp relay will do the job nicely.

[LS120]

or use one of these..

[ShaneJ]

How much did you pay for that? I have one here I'll happily sell.

[LS120]

about $65-75 NZ i think..

[Worby876]

Hey Shane, just saw this thread.
Whilst interested, I have a concern..
Wouldnt the relay need to be rated to the number of amps required to turn the motor over? for instance, if my motor requires 500A to turn over, the relay would then need to be rated to 500A so the earth can feed this amperage thru?

I have my dual battery setup in, with kill switch, but not driving the van for 2 weeks still killed the battery as there is obviously a leak to earth despite MOST things being on the dead side of the kill switch.

Disconnecting the earth would be the best bet..

Would an amp meter. Between the earth terminal of the battery and the chassis detect if there is a current leak? Might need a digital unit that reads from zero to 30 amps as the larger needle type ones would hardly move with a small current. I agree a battery isolation switch is the best way to be sure,
Although some radio sets need standby power to keep the settings and time in the memory etc.

I have a growing collection of dead batteries because my van only gets used now and then and the charger seems to shorten their lifespan, I have since installed a voltage sensitive dual battery relay switch. not sure if this will solve my problems.

Cheers

Ian

Cheers

Ian