low amp probe and multimeter readings

I hooked up my low amp probe to the negative side of the battery to see amperage and I saw a reading of 0.14v on my voltmeter, while on a 20A scale. What does that mean? don't know how to convert it. And i already saw some videos with paul but not clear enough. thanks.

A millivolt is 1 thousandth of a volt. So multiply your 0.14 V by 1,000 to convert it to millivolts. 0.14 V is 140 mV.

Your clamp probably has millivolts per amp for each range marked on it. If it isn't you'll have to look those numbers up in the manual. Divide your mV reading by the mV/A to calculate the amps. If your clamp is 10 mV/A that 140 mV reading would be 14 A.

Agree with Matt T. 14A would be a pretty normal charging rate for an idling engine without loads on.

Matt, I have the snap on low amp probe. I have 20A and 40A scales on my probe. So the setting I had was set to 20A= 100mv/A. So divide my 140mv by 100?

So i divided my 140mv by 20A or 100mv/A?

Mechanic 350 wrote: Matt, I have the snap on low amp probe. I have 20A and 40A scales on my probe. So the setting I had was set to 20A= 100mv/A. So divide my 140mv by 100?

Correct. 140/100=1.4A.