Instructables

12v DC battery amp measurement?

HI,

I have a 12v dc battery and I wanted to measure the amps. Can anyone show me how to hook up the multimeter?

Thanks

Thermionic2 years ago
You can't measure amps in a battery. Electricity doesn't work that way. In order to measure the currrent flowing, you need to connect a load(light bulb, motor). And connect a multimeter in SERIES with the load. This measurement will give you the current flowing, NOT the total producible current of the battery. That measurement is referred to as "amp hours". Amp hours is the amount of time a battery can put put a given current. For that formula, go to Google.
amantux (author)  Thermionic2 years ago
Okay thanks :) That made sense
iceng2 years ago
Measuring a 12V DC battery amps question is usually asked by someone
wanting to know how much power it can deliver..

The easiest measurement of a battery is the voltage.  If it is a lead acid,
zinc,  or NiCad the voltage if carefully done gives information about the
state of charge of a battery.

To measure current capacity takes skill in a quick current measurement
and some knowledge about the batteries amp-Hr rating.
The best strategy is to momentarily try to draw ten times the expected
current draw in use on a dummy load and measure the instantaneous
current and voltage after which the battery impedance and load drop
can be determined.

A
duggerpato2 years ago
Usually batteries are measured in amp-hours.  A simple AA battery I have here shows 2450 mAh (milli-amp hours) or 2.45 amperes for 1 hour.

I think for a 12v DC battery (you mean like a car battery?) you can measure the voltage, and with certain battery chargers it can tell you more, but otherwise you are going to need more than a multimeter to measure the amps. There's one way here on the site: Right here.

aelias362 years ago
Do you mean to ask how to measure amp-hour?