Battery gauge fitting? - SEAT Cupra.net

Hybrid · 07-12-2003, 17:34

Any one got any ideas to where I should get the 12volt supply for my volt meter (ibiza cupra) ?? Got the boost gauge sorted and have conected the lighting for both gauges ok , thanks to the guides on the forum

**m0rk** · 07-12-2003, 17:52

depends what voltage you want to measure?

battery or alternator?

As it's a voltmeter I *think* that you should be able to connect it across the terminals on the battery / alternator that you choose.

It should have a mahoosive resistor inline, so that shouldn't be a problem currentwise.

However, it's not my fault if it doesn't work & I won't buy you a new one

Just that when I plug my Fluke across any of these terminals it's fine.

Do the instructions tell you otherwise?

Mark

*prc* · 07-12-2003, 20:39

I'd just add that if you get it off the fusebox it will be reading 1-2V less than what's actually across the battery terminal. If you do it across the battery make sure to add a fuse (don't want short circuits).

Hybrid · 08-12-2003, 15:33

Cheers both..
It says in the instructions to connect it to the ignition or any 12v supply. I want it to measure the battery so I can keep an eye on if my ICE is effecting it. Could I get the power from my power lead that comes from the battery to my amps? thats got a big fuse on it. or how easy is it to connect it to the ignition supply???

:devil:

*prc* · 08-12-2003, 15:59

You can connect to either, it's just a matter of searching for a 12V lead. The only thing is that if you hook it up dirrectly to the battery it will always be reading the voltage, even with the car off.

GDC · 09-12-2003, 00:18

Ideally you should use an ammeter as well. Ammeter checks what current the alternator is producing and the voltmeter checks the potential difference across the battery terminals. If the voltmeter reading starts to drop overnight then it's a warning the battery is on the way out. If the voltage drops rapidly under load it could be a sign that the alternator isn't charging properly, something that the ammeter would pick-up

To properly test the effects of internal resistance in a battery, a load must be added so that a current will flow through the battery. If no currents flow, no information about the internal resistance can be gotten. Ideally the load added will represent the conditions under which the battery will actually be used. After the load is added to the battery under test, the terminal voltage of the battery is measured with a voltmeter as shown at the left. Thus a battery tester is a voltmeter in parallel with a load resistor, both connected across the battery to be tested. In this case the load resistor is all the electrical gubbins in your car

Put simply the way to check the battery is to connect the voltmeter across the battery, which avoids adding any resistance in line with the battery. The key measure is the voltage when the battery is NOT being charged. Whap up the noise on your ICE and see what it does to the potential difference accros the battery terminals, radiator fan, climate controls and demisters are other big-hitters as can be the lekkie windows

If you haven't got an ammeter (goes in-line with the alternator +ve) then watch what happens to the battery voltage after it's been running off charge fro a while and then when it's been charged up for a while - how quickly does it charge up and how quickly does it drop off again.

Tradionally you install a voltmeter across the battery but using the ignition switch to break the circuit - if you don't then you can drain your battery even with the ignition off, especially if it's a cheap meter and has a low internal impedance.

Is anyone still awake after that?????

*prc* · 09-12-2003, 13:38

:bored: :bored: :bored:

Well if the battery isn't being charged correctly you'll still be able to see big dips in the voltage on the bass notes. I agree with the ammeter "thingy" but it's sort of a big hassle to find one these days (+ the gauge space could be used for other usefull gauges like oil temp).

My 2p..

Hybrid · 10-12-2003, 08:40

Cheers all...
Would of got an oil temp or preasure guage, just thought a volt meter would be easier to fit, I wanted a boost gauge, and wanted to fit it in the Cupra 'R' Ibiza centre console position, which means I need to get a another gauge to fit in the other gauge slot! To late now I've allready got the gauges. Alternativley I could just not connect the voltmeter just the back light, might look a bit shite if its not working though.
So It should be fine to connect it from my power (ice) cable that comes straight from the battery which has a 50AMP fuse ??
What type of cable do I need, power rating wise?
And will the earth off my Head unit do?

GDC · 10-12-2003, 11:34

After my last post I'll just say Yes, 10 Amp cable at least, and Yes (but make sure it's a damn good earth if you're drawing 50 Amps).

*Deejay* · 10-12-2003, 11:50

done this voltage gauge thingy in mine some time ago to moniter the draw from all the vanilla. The needle used too dance all over the place under full load, but will be more stable once I get the 2nd battery and split charge installed.

oil temp/pressure gauges aint that difficult to install once you know what your doing,but as with alot of jobs on the mk3 ibiza 20vt it can be tricky due to its conveluted cramped nature under the bonnet.

Hybrid · 10-12-2003, 13:13

Deejay, what did you connect your voltmeter to ?

Cheers 'GDC', Seems like you've got your head screwed on!! Getting a bit scared now dont want to shag any of my electrics up!!! Should I connect it to somthing a little less current or just put another fuse in line before it hits the gauge? What sort of amp fuse 20 or 30 ?

Sorry cant help being thick when it comes to physics!!

**m0rk** · 10-12-2003, 13:17

the voltmeter will only draw a small current as you will connect it in parallel

Mark

*Deejay* · 11-12-2003, 11:33

Quote:

Originally posted by Hybrid
Deejay, what did you connect your voltmeter to ?

The voltage gauge of mine is installed fused directly off the battery. The problem of the constant gauge supply was overcome with the aid of a 12v contactor and an ignition switch supply to it.

Maplin electronics have all the answers if your stuck.

GDC · 11-12-2003, 18:10

Gotta say Deejay's method is definitely best but counts as hard work. Mark's (obviously) works fine. A 5 amp or even 2 amp fuse will do fine, any more current than that and something is wrong. As Mark says, the voltmeter is in parallel so there's virtually no current through the voltmeter.

Don't worry about the earth for the voltmeter - I was thinking of the earth for the ICE. I'd have thought that, with 50 amps flowing, you'd have been better off with a separate return direct to the battery. Those that have fitted the stuff would know better than me though. I learnt on aircraft in the RAF.

If you're interested and have a high threshold of boredom this is how they used explain voltage and current to us (lecture mode on)....

Think of the wires from the battery as hosepipes carrying water. The current (amps) is the speed the water is flowing through the hosepipe and the voltage is the pressure of the water. Electrical resistance (ohms) is like a restriction in the hosepipe.

If you want to measure the speed you'd shove a little propeller or something in there and see how fast it turned. What you wouldn't want to do is block the flow in any way as that would slow the water down and change the reading. So Ammeters are connected in series (in line with the supply) and have little or no resistance.

If you want to measure the pressure you'd have to run a second hose from the same supply and then block it off and see how hard the water pushed against the barrier. Obviously you have to use a second hose or you'd be blocking up the hose you were using. You couldn't let any water flow through the second hose or you'd drop the pressure in the both. So Voltmeters have a very high resistance and you have to run a parallel line to the supply for your ICE.

They actually used water circuits with coloured water flowing through the hoses to demonstrate and it works exactly as an electrical circuit as long your're talking about DC. A pump to move the water round a closed loop simulates a battery perfectly.

For what it's worth I'm absolutely cr*p at plumbing

Hybrid · 11-12-2003, 19:37

Nice one, cheers ! (after reading it ten times)

I think

I am now a professor in Physics!

Not....
I will let you know when I fry myself and blow my car up!

Hybrid · 11-12-2003, 19:48

Hang on a minute????
So your saying I dont need an earth? Just connect it in parallel to say my power cable with a Fuse, so live off tapped off the power cable through a fuse, into the voltmeter, then live back out to connect to the powercable. So ineffect the voltmeter isnt drawing any power, but the fuse is there just in case?
Or Im I just thick as a door brush?
And you lot are banging your heads together thinking TOSSER !
Cheers all for your help so far... LOL

GDC · 11-12-2003, 20:49

Bang on, the voltmeter doesn't draw any power.

The voltmeter measures the voltage difference between wherever you connect each end. A healthy battery will should show just under 13 volts if you shove one lead onto the postive terminal of the battery and one lead onto the negative terminal.

Cause that's bad practice (anything goes wrong you've got a direct short across the terminals) you normally put a fuse in so that blows instead.

Cause you shouldn't leave anything connected when the ignition is off (bar a few things meant for it, such as clocks) you either put a switch in to break the circuit when the ignition is off (Deejay's Contactor) or you can simply use the power lead that goes from the battery to the ignition switch (what Mark did).

Summary:

Connect the negative lead from the voltmeter to the earth and the positive lead to the power lead that comes out of the ignition switch (the lead that is dead when the igition is off)

If that's difficult to get at you can use any other lead that is switched off when the igniton is off.

Whichever lead you use, put a 5 amp fuse in the lead to the positive terminal on the meter, preferably close the meter.

If in doubt see if Mark will give the exact points he used to wire it in.

I will now shut up before I cause any more confusion....

07-12-2003, 17:34	#1
Hybrid Full Member Join Date: Nov 2002 Location: Newport (S.Wales) Posts: 83	Battery gauge fitting? Any one got any ideas to where I should get the 12volt supply for my volt meter (ibiza cupra) ?? Got the boost gauge sorted and have conected the lighting for both gauges ok , thanks to the guides on the forum

07-12-2003, 17:52	#2
m0rk sarcasm comes free Join Date: May 2001 Location: Horndean, Hants Posts: 29,421	depends what voltage you want to measure? battery or alternator? As it's a voltmeter I think that you should be able to connect it across the terminals on the battery / alternator that you choose. It should have a mahoosive resistor inline, so that shouldn't be a problem currentwise. However, it's not my fault if it doesn't work & I won't buy you a new one Just that when I plug my Fluke across any of these terminals it's fine. Do the instructions tell you otherwise? Mark __________________ m0rksport fleet Skoda Octavia vRS Leon Copa

07-12-2003, 20:39	#3
prc Sooty Meister Join Date: Oct 2001 Location: Here, there, everywhere Posts: 6,073	I'd just add that if you get it off the fusebox it will be reading 1-2V less than what's actually across the battery terminal. If you do it across the battery make sure to add a fuse (don't want short circuits). __________________ Paulo Black Toledo TDI Confusious says: "You'd be surprise just how "UNCUSTOM" custom code is" REVO (Washbrook Special) \| HID Guide\| TDI Fuel Cooler Guide In the works: IC water spray + bigger FMIC

08-12-2003, 15:33	#4
Hybrid Full Member Join Date: Nov 2002 Location: Newport (S.Wales) Posts: 83	Cheers both.. It says in the instructions to connect it to the ignition or any 12v supply. I want it to measure the battery so I can keep an eye on if my ICE is effecting it. Could I get the power from my power lead that comes from the battery to my amps? thats got a big fuse on it. or how easy is it to connect it to the ignition supply??? :devil: __________________ 2007 Seat Leon FR TDI 170, 18" and Bluetooth......

08-12-2003, 15:59	#5
prc Sooty Meister Join Date: Oct 2001 Location: Here, there, everywhere Posts: 6,073	You can connect to either, it's just a matter of searching for a 12V lead. The only thing is that if you hook it up dirrectly to the battery it will always be reading the voltage, even with the car off. __________________ Paulo Black Toledo TDI Confusious says: "You'd be surprise just how "UNCUSTOM" custom code is" REVO (Washbrook Special) \| HID Guide\| TDI Fuel Cooler Guide In the works: IC water spray + bigger FMIC

09-12-2003, 00:18	#6
GDC Old Member Join Date: Mar 2002 Location: Bournemouth Posts: 44	Ideally you should use an ammeter as well. Ammeter checks what current the alternator is producing and the voltmeter checks the potential difference across the battery terminals. If the voltmeter reading starts to drop overnight then it's a warning the battery is on the way out. If the voltage drops rapidly under load it could be a sign that the alternator isn't charging properly, something that the ammeter would pick-up To properly test the effects of internal resistance in a battery, a load must be added so that a current will flow through the battery. If no currents flow, no information about the internal resistance can be gotten. Ideally the load added will represent the conditions under which the battery will actually be used. After the load is added to the battery under test, the terminal voltage of the battery is measured with a voltmeter as shown at the left. Thus a battery tester is a voltmeter in parallel with a load resistor, both connected across the battery to be tested. In this case the load resistor is all the electrical gubbins in your car Put simply the way to check the battery is to connect the voltmeter across the battery, which avoids adding any resistance in line with the battery. The key measure is the voltage when the battery is NOT being charged. Whap up the noise on your ICE and see what it does to the potential difference accros the battery terminals, radiator fan, climate controls and demisters are other big-hitters as can be the lekkie windows If you haven't got an ammeter (goes in-line with the alternator +ve) then watch what happens to the battery voltage after it's been running off charge fro a while and then when it's been charged up for a while - how quickly does it charge up and how quickly does it drop off again. Tradionally you install a voltmeter across the battery but using the ignition switch to break the circuit - if you don't then you can drain your battery even with the ignition off, especially if it's a cheap meter and has a low internal impedance. Is anyone still awake after that?????

09-12-2003, 13:38	#7
prc Sooty Meister Join Date: Oct 2001 Location: Here, there, everywhere Posts: 6,073	:bored: :bored: :bored: Well if the battery isn't being charged correctly you'll still be able to see big dips in the voltage on the bass notes. I agree with the ammeter "thingy" but it's sort of a big hassle to find one these days (+ the gauge space could be used for other usefull gauges like oil temp). My 2p.. __________________ Paulo Black Toledo TDI Confusious says: "You'd be surprise just how "UNCUSTOM" custom code is" REVO (Washbrook Special) \| HID Guide\| TDI Fuel Cooler Guide In the works: IC water spray + bigger FMIC

10-12-2003, 08:40	#8
Hybrid Full Member Join Date: Nov 2002 Location: Newport (S.Wales) Posts: 83	Cheers all... Would of got an oil temp or preasure guage, just thought a volt meter would be easier to fit, I wanted a boost gauge, and wanted to fit it in the Cupra 'R' Ibiza centre console position, which means I need to get a another gauge to fit in the other gauge slot! To late now I've allready got the gauges. Alternativley I could just not connect the voltmeter just the back light, might look a bit shite if its not working though. So It should be fine to connect it from my power (ice) cable that comes straight from the battery which has a 50AMP fuse ?? What type of cable do I need, power rating wise? And will the earth off my Head unit do? __________________ 2007 Seat Leon FR TDI 170, 18" and Bluetooth......

10-12-2003, 11:34	#9
GDC Old Member Join Date: Mar 2002 Location: Bournemouth Posts: 44	After my last post I'll just say Yes, 10 Amp cable at least, and Yes (but make sure it's a damn good earth if you're drawing 50 Amps).

10-12-2003, 11:50	#10
Deejay no prawn sarnies ere Join Date: Nov 2002 Location: ЯEPUБLIC OF MANCUNIA Posts: 1,127	done this voltage gauge thingy in mine some time ago to moniter the draw from all the vanilla. The needle used too dance all over the place under full load, but will be more stable once I get the 2nd battery and split charge installed. oil temp/pressure gauges aint that difficult to install once you know what your doing,but as with alot of jobs on the mk3 ibiza 20vt it can be tricky due to its conveluted cramped nature under the bonnet. __________________ IBIZA CUPRA

10-12-2003, 13:13	#11
Hybrid Full Member Join Date: Nov 2002 Location: Newport (S.Wales) Posts: 83	Deejay, what did you connect your voltmeter to ? Cheers 'GDC', Seems like you've got your head screwed on!! Getting a bit scared now dont want to shag any of my electrics up!!! Should I connect it to somthing a little less current or just put another fuse in line before it hits the gauge? What sort of amp fuse 20 or 30 ? Sorry cant help being thick when it comes to physics!! __________________ 2007 Seat Leon FR TDI 170, 18" and Bluetooth......

10-12-2003, 13:17	#12
m0rk sarcasm comes free Join Date: May 2001 Location: Horndean, Hants Posts: 29,421	the voltmeter will only draw a small current as you will connect it in parallel Mark __________________ m0rksport fleet Skoda Octavia vRS Leon Copa

11-12-2003, 18:10	#14
GDC Old Member Join Date: Mar 2002 Location: Bournemouth Posts: 44	Gotta say Deejay's method is definitely best but counts as hard work. Mark's (obviously) works fine. A 5 amp or even 2 amp fuse will do fine, any more current than that and something is wrong. As Mark says, the voltmeter is in parallel so there's virtually no current through the voltmeter. Don't worry about the earth for the voltmeter - I was thinking of the earth for the ICE. I'd have thought that, with 50 amps flowing, you'd have been better off with a separate return direct to the battery. Those that have fitted the stuff would know better than me though. I learnt on aircraft in the RAF. If you're interested and have a high threshold of boredom this is how they used explain voltage and current to us (lecture mode on).... Think of the wires from the battery as hosepipes carrying water. The current (amps) is the speed the water is flowing through the hosepipe and the voltage is the pressure of the water. Electrical resistance (ohms) is like a restriction in the hosepipe. If you want to measure the speed you'd shove a little propeller or something in there and see how fast it turned. What you wouldn't want to do is block the flow in any way as that would slow the water down and change the reading. So Ammeters are connected in series (in line with the supply) and have little or no resistance. If you want to measure the pressure you'd have to run a second hose from the same supply and then block it off and see how hard the water pushed against the barrier. Obviously you have to use a second hose or you'd be blocking up the hose you were using. You couldn't let any water flow through the second hose or you'd drop the pressure in the both. So Voltmeters have a very high resistance and you have to run a parallel line to the supply for your ICE. They actually used water circuits with coloured water flowing through the hoses to demonstrate and it works exactly as an electrical circuit as long your're talking about DC. A pump to move the water round a closed loop simulates a battery perfectly. For what it's worth I'm absolutely cr*p at plumbing

11-12-2003, 19:37	#15
Hybrid Full Member Join Date: Nov 2002 Location: Newport (S.Wales) Posts: 83	Nice one, cheers ! (after reading it ten times) I think I am now a professor in Physics! Not.... I will let you know when I fry myself and blow my car up! __________________ 2007 Seat Leon FR TDI 170, 18" and Bluetooth......

11-12-2003, 19:48	#16
Hybrid Full Member Join Date: Nov 2002 Location: Newport (S.Wales) Posts: 83	Hang on a minute???? So your saying I dont need an earth? Just connect it in parallel to say my power cable with a Fuse, so live off tapped off the power cable through a fuse, into the voltmeter, then live back out to connect to the powercable. So ineffect the voltmeter isnt drawing any power, but the fuse is there just in case? Or Im I just thick as a door brush? And you lot are banging your heads together thinking TOSSER ! Cheers all for your help so far... LOL __________________ 2007 Seat Leon FR TDI 170, 18" and Bluetooth......

11-12-2003, 20:49	#17
GDC Old Member Join Date: Mar 2002 Location: Bournemouth Posts: 44	Bang on, the voltmeter doesn't draw any power. The voltmeter measures the voltage difference between wherever you connect each end. A healthy battery will should show just under 13 volts if you shove one lead onto the postive terminal of the battery and one lead onto the negative terminal. Cause that's bad practice (anything goes wrong you've got a direct short across the terminals) you normally put a fuse in so that blows instead. Cause you shouldn't leave anything connected when the ignition is off (bar a few things meant for it, such as clocks) you either put a switch in to break the circuit when the ignition is off (Deejay's Contactor) or you can simply use the power lead that goes from the battery to the ignition switch (what Mark did). Summary: Connect the negative lead from the voltmeter to the earth and the positive lead to the power lead that comes out of the ignition switch (the lead that is dead when the igition is off) If that's difficult to get at you can use any other lead that is switched off when the igniton is off. Whichever lead you use, put a 5 amp fuse in the lead to the positive terminal on the meter, preferably close the meter. If in doubt see if Mark will give the exact points he used to wire it in. I will now shut up before I cause any more confusion....

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

(View-All) Members who have read this thread : 13
antzleoncupra, arthuryounguk, browncolin, chris_200120vt, fulls1982, GottaIbizaMk3, joshW, kieran cupra, marcus_cupra, Pabs, peter_cupra197, swilky23, tomcupra

Thread Tools
Show Printable Version Email this Page
Display Modes	Rate This Thread
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode	Rate This Thread: