Volts or Amps

[Jim-ME]

I have always felt more comfortable with gauges and am interested in either a volt or an amp gauge. Which is the way to go and why?
Jim

[Mercedesrover]

Volts will tell you all you need to know and are easier to hook up.

[greenmeanie]

Volts will tell you about the health of your charge system. Amps tells you the load on your system. Volts is better because it can be wired in parallel with the main power bus while an Amp gauge is in series. A failed volt gauge will not kill your electrical system.

There's a bit more here:

http://madelectrical.com/electricaltech/amp-gauges.shtml

Cheers
Gregor

[Jim-ME]

Thank you gentlemen. That's what I thought but wanted to be sure.
Jim

[S11A]

I agree that the voltmeter would be better if you choose only one.

But a bit more on ammeters: Normally an ammeter works by running the current through the meter and actually measuring amps, but another method is to insert a shunt of known voltage drop in line with main cable. The more current that goes through the shunt, the more voltage drop (normally in the range of 50mV, so not much). The ammeters that use shunts are actually voltmeters that measure the voltage drop, but with the dial graduated in Amps. Since Voltage and Amperage are directly related, this method is quite accurate. The shunt type meters are useful for electrical systems that have a lot of current running through them, where you would not want say 200A running through the dashboard

Another method is to indirectly measure the current via the Hall effect. Check this doohicky out:

http://www.tst-corp.com/pdfs/Controls_products/Hall_Effect_Current_Sensors.pdf

http://store.lifestarrescue.com/index.asp?PageAction=VIEWPROD&ProdID=13121

I am thinking I will install both a voltmeter, as well as an ammeter using the Hall effect sensor.

[sven]

I'd like to add a voltmeter to my S3. Has anyone found an aftermarket one that looks Ok in a series rover? All the ones at my local autoparts store are carbon fiber

[greenmeanie]

Check out the VDO gauges. They have some nice simple white digits on black.

Cheers
Gregor

[S11A]

Nisonger has Smiths gauges:

http://www.nisonger.com/smiths-classic-gauges.htm