Adding dash voltage gauge for trolling motor batteries.

gm280

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Jun 26, 2011
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I understand parallel and series in general when connecting batteries but adding a volt gauge to this setup somehow warped my brain.

I think Im getting confused because the motor pulls 35 amps but somehow the small wires of the volt gauge do not - even though they are connected to the same circuit. I really need to draw out a proper electrical schematic for this.
You somehow are talking about two totally different things. Yes, your trolling motor pulls 35 amps. But the voltage, for all practical purposes, stays the same...12 volts for this discussion. Look at it this way, if you are running your AC in your home or water heater or washing machine, and take a volt meter and measure any outlet in your home, the current running the AC or water heater or even the washing machine isn't going through the volt meter as you test the wall receptacle. And all of them are coming from the exact same source. The voltage meter only draws enough current to make the reading. And depending on the meter, we are merely talking a few milliamps (1/1000 of an amp) at best. Look at it like a garden hose. The water pressure is one thing, the actual water flow is another. The pressure is equivalent to the voltage, and the actual water flow is the current. If you have a water pressure gauge, it couldn't care how much water is flowing, that is measured in gallons... Does that help explain it?
If you measure the voltage at the battery with the trolling motor on or any other electrical device on, the only thing that changes is the very slight drop in voltage as you power up more devices. But each device draws it's own current/amps to operate. A panel light uses the exact same voltage but nowhere near the same amperage as the trolling motor. That is why the trolling motor wires are very large diameter wires while the panel light is a lot smaller diameter wires...even with both using the same battery at the same time.
 
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