[DarkHorse]

Hey all,

I have a dual battery setup with an ARB Sidewinder DBi140R.

I want to run a guage for each battery - have tried wiring them but things are a bit weird, hopefully someone smarter can tell me why.

What I've done:
- main guage tapped into the stereo power supply (switched on ACC circuit)
- aux guage power is coming straight from the battery via a fusebox, with the UHF bridged in (UHF earth goes to stereo earth)
- I figured since both batteries earth straight to the body the guages could share an earth, so I joined them both together and ran it to the stereo earth too

What's happening:
- with car switched off the aux guage only lights up
- with the car switched to ACC or running neither guage lights up
- when everything is killed for the starter the aux guage comes back on
- UHF powers and works as expected, as does everything else
- the aux guage reads lower with the headlights on, or winding windows (both still wired to main loom as per factory.)

I'm guessing the problem is with the common earth? Negative switching? Earthing on the ACC circuit? Every time I look at the isolator the LED indicator is on, which from memory means the batteries are NOT isolated? Does that explain the aux guage reacting to what should be main power draw?

Should I just cut my losses and run a + and - straight from each battery?

Any help appreciated, thanks guys!

[royce]

what gauges?

sounds like you have the wrong wires in the wrong spot on the gauge, or you have them earthed to a acc power wire

[DarkHorse]

Cheap eBay jobbies:


Will check the earth, but pretty sure it's tapped into the same earth the stereo and interior power is running (and the UHF) all of which is functioning normally.

It's just a white and a black wire out of each guage, the black ones are soldered together and run to what I hope is an earth, the white one for aux guage is run to a line from the aux battery via the fuse box... and it's working even if it's giving odd readings...

[royce]

I would pull em both and test each direct to a battery to make sure they work

then check your earth, it makes sense the earth you used is live at ACC for the faults, but not if the other stuff is working off it fine

[stocker]

I agree with royce, the problem you have is not the Common earth. or negative switching...

Sounds like your problem is with the connections on the positive side.

One would assume you are going to only want them on when the Accessories are on or perhaps via a switch (permanently connected they will obviously drain your battery)

So rather than trying to "tap in" to other circuits. why don't you Run a 2 Pole 12V Relay?
Directly connect the Voltmeters to each battery Terminal (fused of course )
then either use a Switch (permanent power) or Accessory wire to Switch the Relay?
this will give you a more accurate reading of what the batteries are doing. Rather than measuring
what the Headunits Voltage Drop is


EDIT : If you don't want to use a relay, you can Also just use two switches instead.
But either way, Direct connection to the battery Is the way to go (Don't forget to Fuse it!!!)

[DarkHorse]

Hmmm, thanks guys.

Royce - I did check them both direct before I installed them, and they were both OK at that point. Will re-earth tomorrow.

stocker - was trying to avoid the effort of running two lines through the firewall (one was painful enough) and relays etc. Ideally it would be nice to have them both ACC switched, guess I should just bite the bullet.

I'm already putting a switch to bypass the isolator beneath the guages and there isn't really room for two more!

Cheers again gents.

[stocker]

Another option dark horse.

-Run One Gauge on a Twin position switch (you don't really need to see both battery voltages at once do you?)

[DarkHorse]

Did think about that and decided I'd rather have them both.

Thanks for the suggestion though.

[DarkHorse]

Found it.

Problem was, predictably, that I'm a moron.

As diagnosed, the leads for the main guage and the shared earth were round the wrong way, so earth was ACC switched and there was no power feed for it.

Thanks agin blokes.

[DarkHorse]

I actually like the way they are hooked up now - the main one switches on and off with the car, so no drain. The aux one is on all the time, so I can keep track of the drain as accessories run off it. It's only LED, and so far it hasn't dropped below 11.0V overnight.

[stocker]

if it drops to 11.0V over night... i wouldn't wanna leave it for a couple of days ( you may collapse a cell in the battery)

[DarkHorse]

Yeah, probably disconnect the aux battery totally when I go away tomorrow - it's powering the rearview camera IR LEDs constantly at the moment.

[royce]

holy crap 11v is really bad!

[want33s]

DarkHorse wrote:

- it's powering the rearview camera IR LEDs constantly at the moment.

Why isn't the camera/LEDs hooked to the reverse light circuit? Should only be powered when needed..

[stocker]

royce wrote:

holy crap 11v is really bad!

x 20000000000000

[DarkHorse]

want33s wrote:

DarkHorse wrote:

- it's powering the rearview camera IR LEDs constantly at the moment.

Why isn't the camera/LEDs hooked to the reverse light circuit? Should only be powered when needed..

Laziness on my part. It's on the list to do, but at the moment the monitor isn't getting power anyway, so I've got to track that first.

I'm a little worried about the voltage drop, but it's only the aux battery, I know it's had a hard life and isn't in the greatest condition (was flattened completely a couple of times when it was my only/starter battery) and it's a temporary measure. Will only get full loads winching when the engine is running and it's getting alt current, so it'll do for now.

[stocker]

DarkHorse wrote:

want33s wrote:

DarkHorse wrote:

- it's powering the rearview camera IR LEDs constantly at the moment.

Why isn't the camera/LEDs hooked to the reverse light circuit? Should only be powered when needed..

Laziness on my part. It's on the list to do, but at the moment the monitor isn't getting power anyway, so I've got to track that first.

I'm a little worried about the voltage drop, but it's only the aux battery, I know it's had a hard life and isn't in the greatest condition (was flattened completely a couple of times when it was my only/starter battery) and it's a temporary measure. Will only get full loads winching when the engine is running and it's getting alt current, so it'll do for now.

yes your right, a dodgy battery will drop voltage overnight, the plates inside the battery become corroded and break down, that therefore adds more internal resistance in the battery causes a current and well you know how the story goes....

the other thing is...

im under the assumption you have a few things connected to the terminals on the Battery, my advice is just to take one off at a time and leave it overnight... when it stops dropping voltage, then you'll know what it is... if it is indeed not the battery that is the problem...

[DarkHorse]

Thanks for that stocker, will check it out. At the moment the aux battery is running winch, compressor, spotties, awning lights, UHF, inverter - all through fuses and all are switched off or disconnected normally. The rearview is the only thing running constantly.