diy volt meter on the cheap

ok so went looking for a voltage meter for my car and discovered that the arb/tjm/whatever brand were way overpriced so out the window went that idea and in with my new idea.

went into jaycar and managed to find myself a digital dc voltage display and since i have 2 batteries i picked up a 3 way momentary on switch(on/off/on)

total project cost: $18 monitor, $12 switch. 30$ total ($50 with cable)

and so began my installation.
roughed in cable to both battery actives and a neutral/ground to the chassis and terminated

active from the moniter to the commen
and each active from the batteries to either side and ground to ground.

note: i have an rx model so monitor was installed where the power window should go.
since i only had twin i picked up from work the white acted as my neutral.

p.s. i know my cutting was a bit wonkey but oh well.

That's very handy for monitoring the aux battery. Good stuff!

Pity that area's used on my car already. I don't have any mechanism to check the aux battery while I'm on the move. It's a good idea! My aux battery is charged by 240V charger (inverter-supplied) while I'm driving, but I have no idea of the state-of-charge. This would answer that!

I have one of these connected to my PV Solar Controller works well

Forgot to mention they also do a amp meter the same size but has an external shunt for about $30

yeh i mainly use this offroad once the solinoid kicks out, to monitor the voltage for my engels so it doesnt run out.

I once had similar ideas about battery monitoring, originally I wanted a pillar pod with a dual battery monitor but considering the outrageous prices of those things I quickly decided that ScanGauge could monitor the main battery and the Aux could look after itself.

I ended up installing a $5 colour coded analogue meter that reads between 9 and 15v in the tub above the battery box. The colour coded meter means I only have to glance at it to know the state of the battery and unless it's way down in the yellow there is no concern for monitoring it any more closely.

I understand some people want to keep a close eyes on things, years ago I used to think the same way but these days whats in the back of the ute gets checked when the car stops or before the car starts again and the rest of the time it runs itself just like I set it up to do. I haven't even checked the voltage of my aux battery in 2 months because I just don't think about it, but at the same time I have no cause to think it will be at anything other than full charge.

Maybe I should check my aux battery more often. The only time it ever gets checked is every service its get trickle charged to top it off or before camp trips.

Thanks for the post, been looking for a volt meter like that locally (in darwin) for a while. Went to Jay Car today and picked my self up one.

I think the location shown is where a power mirror setup would go - the power windows are in the arm rest of each door

But i like your thinking and a great install.

Nice install...trying to find a spot in my d22 that hasnt been taken up already

Hey guys.

I bought a few things to do my volt meter the other day. I have wired it up and it is working, but i have a question.

First of all this is what i bought...

http://www.ebay.com.au/itm/Red-DC-7...Electrical_Test_Equipment&hash=item3f17da2d97

http://www.ebay.com.au/itm/5Pcs-Blu...=AU_Car_Parts_Accessories&hash=item1c25606a8b

What i have done is taken power direct from the battery and wired it to the positive of the switch, then I have taken the positive line from the voltmeter and wired it to the middle pole which is only ever made live by flicking switch.

The question i have is, Will this setup actually slowly drain my battery when the car is parked and the switch is in the off position?

Reason I'm asking is because I'm not sure if i should have a relay in there between the battery and the switch that only allows power to the switch when the ignition is on. The way i have wired it up seems too easy and I'm concerned that it will in fact drain my battery.

EDIT - It is currently disconnected until i get an inline fuse and just in case I'm right and it is a bad way of doing it

Cheers

Christian

$7 from eBay

stockstandard said:

Hey guys.

I bought a few things to do my volt meter the other day. I have wired it up and it is working, but i have a question.

First of all this is what i bought...

http://www.ebay.com.au/itm/Red-DC-7...Electrical_Test_Equipment&hash=item3f17da2d97

http://www.ebay.com.au/itm/5Pcs-Blu...=AU_Car_Parts_Accessories&hash=item1c25606a8b

What i have done is taken power direct from the battery and wired it to the positive of the switch, then I have taken the positive line from the voltmeter and wired it to the middle pole which is only ever made live by flicking switch.

The question i have is, Will this setup actually slowly drain my battery when the car is parked and the switch is in the off position?

Reason I'm asking is because I'm not sure if i should have a relay in there between the battery and the switch that only allows power to the switch when the ignition is on. The way i have wired it up seems too easy and I'm concerned that it will in fact drain my battery.

EDIT - It is currently disconnected until i get an inline fuse and just in case I'm right and it is a bad way of doing it

Cheers

Christian

Click to expand...

Assuming the middle pole is illumination unless it is wired to always on no power will be drained.

d40ryan said:

Assuming the middle pole is illumination unless it is wired to always on no power will be drained.

Click to expand...

the voltmeter and led on the switch illuminates only when the switch is flicked to the on position. So my thinking was that its not going to drain any power, just wanted to be sure i wasn't doing something seriously wrong.

Cheers

C

You're not doing anything wrong with the switch like that.

I'd put a 2A fuse in the cable close to the battery. That's not to protect the device, it's to protect the cable you're connecting to the battery. If the cable gets damaged and shorts out, it'll cause all sorts of drama. The 2A fuse will prevent that (and you won't need anything bigger than 2A - you could probably get away with smaller).

Old.Tony said:

You're not doing anything wrong with the switch like that.

I'd put a 2A fuse in the cable close to the battery. That's not to protect the device, it's to protect the cable you're connecting to the battery. If the cable gets damaged and shorts out, it'll cause all sorts of drama. The 2A fuse will prevent that (and you won't need anything bigger than 2A - you could probably get away with smaller).

Click to expand...

Champion....cheers mate.

I'll try and get some pics of it later on. Fair to say all up it will cost me under $15 easily. I ordered all the parts from ebay and i'm fairly sure they all came from HK. Time will tell how they hold up.

I have also ordered some gauges to chuck in as well ( BOOST, EGT, WATER TEMP ). Brand is RACE TECH, have heard good and bad things about them. From what i can tell by looking at mine they seem quite similar to DEFI brand gauges, but as far as build quality is concerned im not sure.

They are electric and use a stepper motor so they should be quite accurate. All come with necessary sensors to get them hooked up. I grabbed a DIN gauge holder as well while i was at it so i can chuck them under my stereo.

Will keep you updated.

stockstandard said:

the voltmeter and led on the switch illuminates only when the switch is flicked to the on position. So my thinking was that its not going to drain any power, just wanted to be sure i wasn't doing something seriously wrong.

Cheers

C

Click to expand...

It's only 12v. But yeh use a fuse anyways although it shouldn't draw more the 1/8 amp or something stupid, your cable will be over rated.