[jsmith24]

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Hi folks,

I would like to add a gauge to monitor my charging system (83 Interstate). In your opinions, would it be best to have an ammeter, voltmeter, or both? Where does one find good motorcycle gauges? I think the ammeter range should be in the 30 amp swing, not 60 amps...does that sound right?

Jack

 

[JDuggan]

imported post

A voltmeter is simpler to install. Ammeters are much more accurate as the measure the remaing amps in the battery, but they need very heavy wire going through them as themain lead from thebatteryhas to pass through the ammeter and back out to the bikes electrics. Many a horror story I've heard of cars going on fire because of badly wired ammeters. A 30 amp range is probably right for your bike.

 

[Silicon Sam]

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If I remember my electronics training right, all the ammeter will do is show the current draw from the battery. There is no way to measure amperage left in a battery per se.

Raymond

 

[JDuggan]

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You're right Raymond, I worded that wrongly. Apologies for the confusion.

 

[corneo]

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Volt meter will show the current charge level of the battery. If your riding it will show what the battery charger/alternator is bringing the batter level up to. It is the quickest way to tell if your alternator is not working. WhenI'm riding, my volt meter shows I am getting about 14 volts charge to the battery.

 

[exavid]

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I'd agree that the voltmeter is the best choice, it's the easiest to connect and it really gives the same information you'd get from an ammeter. If your voltage is 13V or more you're charging the battery, if it's lower than the normal open circuit battery voltage, less than 12V for all practical purposes, your battery is discharging.

Admittedlyan ammeter gives direct information about the above conditions, but the voltmeter give just as good information albeit indirect and is a lot simpler to install, just hook it to a circuit that comes on with the ignition key, the radio lead is good since you can then see the voltage while the key is in the accessory position. Don't worry about the current drain of a voltmeter, it draws very low current, since it's resistance is in the range of 100,000 ohms or more.