Forum Discussion

Explorer

May 27, 2016

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 is the following statements are correct:

Okay, so from what I can find online, I remove the trailer from shore power. Make sure everything is OFF in the trailer, including the light in the storage bay.

I take my new Craftsman clamp meter and put ONE (either one) of the trailer's battery cables inside the hole of the meter. The meter should read ZERO.

So far, is this correct?
I haven't done something to electrocute myself?
Or burned down the garage?

But I have since read that I should put the clamp on the ground (negative) wire of the battery?

Baby steps...

23 Replies

Boon_Docker
Explorer III
May 28, 2016
You will not get an accurate reading off the battery cable, because there will be other draw on the battery also such as CO detector, propane detector, smoke detector, stereo standby etc.

If the fridge is on a circuit all by itself, you could pull all the fuses except the fridge fuse then check current draw at the battery cable.
Almot
Explorer III
May 28, 2016
Measuring it on battery cables you will measure the "battery" current. Not the fridge current.

1-1.5A is what it draws when cycling. Plus something little when not. Big question is how often and how long it cycles, and for that you need to measure not amps but AH.

But, if the purpose was to learn how to use clamp on meter, for future needs, go ahead, put it on either wire.
RJsfishin
Explorer
May 27, 2016
A much more accurate way would be an inline in series ampmeter at the refridgerator