Trailer Battery Usage
I would like to measure refrigerator current on my trailer battery when fridge is on propane. Got the Sears 82369 Sears ClampMeter Never having owned a clamp meter before, can someone explain i...
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Is the fridge so big that you really need a light in there?? Nice!
Anyway, this is the method that I used to test the draw of each of the fixtures and devices in my trailer. I did not have a clamp on ammeter, so I just used an ordinary multi-meter. You probably already know this stuff, but just in case, here it is:
1. Make sure everything in the RV is off.
2. Disconnect the battery, using the battery disconnect switch.
3. Put the red (positive) multimeter plug into the 10 amp socket on the front of the multimeter. (I'm assuming that this is a pretty standard set up – I've only seen a few multimeters, and they all had this feature. If I'm wrong, I'm sure somebody will let me know.)
4. Unhook the negative terminal of the battery. Using an alligator clip, clip the multimeter's red lead to the negative cable (the one that would've been connected to the battery). (You could probably also use masking tape instead of an alligator clip.)
5. Using an alligator clip, clip the black lead to the screw post of the negative terminal on the battery. I think that what I've just described is called hooking up the multimeter "in series" – i.e., the current has to flow from the negative battery cable through the multimeter to the negative terminal. (Again, if I'm wrong on my terminology, I'd appreciate it if somebody would set me straight.)
6. Turn the multimeter on to the 10 amp setting. It should read "zero."
7. Reconnect the battery, using the battery disconnect switch. You should get a fairly low reading – this is the background or parasitic draw of the carbon monoxide monitor, the smoke detector, and the propane detector.
8. Turn on each of the electrical devices in your RV, one at a time, and see how the meter changes. So, for example, if the background number is 0.10 amps, and the meter jumps to 0.30, you know that whatever you are testing draws 0.20 amps.
You can then determine how much current each of your electrical devices is drawing. There is a formula for converting amps to watts, but (frankly) it's a lot easier to use the conversion utilities that are provided free on the Internet.
I hope this helps!
Anyway, this is the method that I used to test the draw of each of the fixtures and devices in my trailer. I did not have a clamp on ammeter, so I just used an ordinary multi-meter. You probably already know this stuff, but just in case, here it is:
1. Make sure everything in the RV is off.
2. Disconnect the battery, using the battery disconnect switch.
3. Put the red (positive) multimeter plug into the 10 amp socket on the front of the multimeter. (I'm assuming that this is a pretty standard set up – I've only seen a few multimeters, and they all had this feature. If I'm wrong, I'm sure somebody will let me know.)
4. Unhook the negative terminal of the battery. Using an alligator clip, clip the multimeter's red lead to the negative cable (the one that would've been connected to the battery). (You could probably also use masking tape instead of an alligator clip.)
5. Using an alligator clip, clip the black lead to the screw post of the negative terminal on the battery. I think that what I've just described is called hooking up the multimeter "in series" – i.e., the current has to flow from the negative battery cable through the multimeter to the negative terminal. (Again, if I'm wrong on my terminology, I'd appreciate it if somebody would set me straight.)
6. Turn the multimeter on to the 10 amp setting. It should read "zero."
7. Reconnect the battery, using the battery disconnect switch. You should get a fairly low reading – this is the background or parasitic draw of the carbon monoxide monitor, the smoke detector, and the propane detector.
8. Turn on each of the electrical devices in your RV, one at a time, and see how the meter changes. So, for example, if the background number is 0.10 amps, and the meter jumps to 0.30, you know that whatever you are testing draws 0.20 amps.
You can then determine how much current each of your electrical devices is drawing. There is a formula for converting amps to watts, but (frankly) it's a lot easier to use the conversion utilities that are provided free on the Internet.
I hope this helps!
