Voltmeter with standard dual batteries

[scooba_285]

Going to put in one or two voltmeters (not sure how many yet), i have a 09 and has factory dual batteries, not sure if just one will do but thought it might seeing they are wired together, can i connect it to the cig lighter or does it need to be direct to battery?
Cheers

 

[Old.Tony]

The cig lighter will be fine. Both batteries are connected in parallel so reading one will show the voltage of the other.

That may not be the case if you had installed an isolator.

 

[75 GRC]

Scooba,

I think the question is do you want to know exactly the voltage of each individual battery ????

Or are you just happy to get a Voltage reading overall???

I would personally like to know exactly what each battery is doing (regardless of running parallel)
That would be my thought!

 

[tony d22]

You can just hook up to the battery terminals themselves.
That might give you what your after.

 

[04HUG]

G'day

I'm using the OBD2 port and a scangauge.

 

[Old.Tony]

If the batteries are connected via a single heavy cable then there's not going to be a difference in reading between one and the other. If there's an isolator in the way you'll have a difference while the isolator is inactive.

You could get a 150A relay which is activated by ignition so that the aux battery is disconnected while the ignition is off, and then you'd benefit from having a display connected to the aux battery.

 

[abouttogobush]

Also the cig lighter output will give .3-.5 volts difference less than that of a good twin cable to the battery terminals. "If your fussy".

 

[scooba_285]

Cig lighter will do then haha
Thanks for the info