dual battery switch

[delrazor]

Hi, is anyone familiar with the dual battery switch that I have discovered in my van?
If you look carefully at the pic, you'll see a big black knob that looks like a big kitchen tap.

[Kirk]

I see your knob...i see your knob...ohhhh hangon this wasnt a "Spot the.." game was it?? ahaha Nope i dont have one, i doubt my battery area would fit 2 full size batteries....is yours swb or lwb?

[ShaneJ]

Looks like a manually operated dual battery switch. Not a very good spot to mount it if you want to switch batteries often.

[Marishka]

yep looks like a dual battery switch2 me.
it will have 4 positions like a clock face 12 3, 6 and 9oclock

batt /1
both batteries
battery 2
and no power at all

its not advisable to switch between settings while motor is running.
and alternate between the 2 single battery settings when charging .
starts a motor unreal on both.
but still gives just 12volts on 1, 2 or both. 

i put 1 in my van and in my boat.
passanger side of my van =

[ShaneJ]

Now thats a better position for it.

[delrazor]

excellent news. At least we can camp without the worry of getting stuck.
What happens when one battery shits itself?

[Marishka]

if 1 goes dead, switch to both, start and switch back to the flat 1 and drive a good distance,
u can swap from 1 battery to both and to second battery while its running but i was told it damages the inside terminals, if done too much.

also read the writeing on the dial=
says not to turn to off position while motor is running.

if camping try use 1 battery , always keep 1 full.
but ive had 2 flat batteries out in my boat (before i fitted the twin battery switch)on a weekday in a secluded spot with no chance of a jump off a passing boat and just wired the 2 batteries in a series like 2x 6 volt batteries=12volts and got the motor going and back 2 civilisation.
but dont do that with 2 x fully charged batteries as it will produce 24volts and fry 12volt electrical things.

[Warren]

Delrazor
Check out what type of batteries they are, one should be a cranking (normal) battery and the other a deep cycle battery.

The cranking battery is designed to give large current draw for a short period of time and stay at 12 volts, then be recharged back to full quickly - usd for normal car stuff - mainly starting the engine.

The deep cycle battery or house battery is designed to give a smaller current draw over a longer period, and can drop its voltage below 12 volts and recover after charging, and can do this regularly.

The deep cycle battery is for the vans lights fidge etc when camped up.

When driving the switch should be to both batteries, when you camp for the night you switch over to just the deep cycle battery, keeping the craking battery "full" for the next start up, usually the next morning.

When you go to start the van the next morning you switch to the cranking battery only, start the engine and let it idle/warm up and top up the cranking battery again.

Then you switch to the two batteries again so that both will be charged up while you drive.

Someone on here showed how to automate this proccess with two relays, better tnan having to remeber switch it over all the time

Warren

     

[ShaneJ]

I can show how to simplify the process with just one relay. I'll do a diagram when I get a spare 5 minutes.

[Warren]

Yes please Shane

Warren