How do I test the mA drain from an accessory ?

[NeilW]

I have a digital voltmeter and want to test the voltage / amp drain from a new alarm/gps bike tracker. Someone please tell me how to see the drain in real time?

Thanks

[Alan M]

Select DC mA/A on your multimeter.

 

Disconnect the negative terminal from your battery and connect the meter in series between the battery negative lead and the negative battery terminal.

 

Make sure the multimeter leads are connected between common and current terminal on the meter. This should give you the overall battery drain current. If you only want to see the actual accessory, alarm etc, just connect the meter in series with the negative supply to the accessory. You can also connect to the positive but negative is safer.

 

PS don’t try and start the bike with the meter in series with the battery, ok if only connected to the actual accessory.

Edited November 29, 2023 by Alan M
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[NeilW]

Thank you.  

[thepointchris]

6 hours ago, Alan M said:

Select DC mA/A on your multimeter.

 

Disconnect the negative terminal from your battery and connect the meter in series between the battery negative lead and the negative battery terminal.

 

Make sure the multimeter leads are connected between common and current terminal on the meter. This should give you the overall battery drain current. If you only want to see the actual accessory, alarm etc, just connect the meter in series with the negative supply to the accessory. You can also connect to the positive but negative is safer.

 

PS don’t try and start the bike with the meter in series with the battery, ok if only connected to the actual accessory.

what a great, detailed, concise reply to a technical question - you gotta love the people here!

[NeilW]

5 minutes ago, thepointchris said:

what a great, detailed, concise reply to a technical question - you gotta love the people here!

I agree and I do. I try to live up to the level of the support given on this forum.

[Tenerider]

A hint: Start in DC A setting, if available, not mA.

This way, the chance to blow the multimeter's fuse due to overcurrent is reduced.

If it doesn't have such fuse, it's even more important (because the multimeter itself might blow up).

 

Only if your reading in A shows reasonably low numbers, switch to mA range (you sometimes need to reconnect the black multineter lead to another port for mA measuring).

[NeilW]

Set it like this photo?

 

 

[Tenerider]

1 hour ago, NeilW said:

Set it like this photo?

 

 

Perfect! And this multimeter definitely is fused by the way. I don't think money can buy anything better than a Fluke.

 

If your reading shows less than 0.3 A, you may move the red lead to the corresponding port (for a higher accuracy).

Edited November 30, 2023 by Tenerider

[BikeBrother]

What about AC/DC?

Good info!

 

[electric_monk]

Have a look at this video