Digital Multimeter help please

[badass88gt]

Is there a way I can take my digital multimeter and measure the total draw off the battery of my camper? I'm not real fluent with my tester, this is what I have. Thanks for any help! Dan

http://members.aol.com/badazzred88gt/Pics/meter.jpg

[Reverend Cooper]

dc 200m run power threw the multimeter to measure it off power side,or 20m depends what kinda draw it has how much

[badass88gt]

So I pull the positive off the battery, stick the meter in line, and leave the negative on the battery alone?

[Heat Seeker WS6]

Yes , run it is series (inline) to measure the current draw. Be careful no to touch the leads to anything but the battery terminal & the lead; and like Coooooooooop said, start with the 200m DC setting in case you get a rush-in current that'd be too high for the 20m DC setting.

[badass88gt]

You mean the 200m on the right side, in green, in the DCA box right?

[fivonut]

Is there a way I can take my digital multimeter and measure the total draw off the battery of my camper?

It depends on when you measure it, if you're trying to measure draw with everything on then, no. If you're looking for parasitic draw when everything is off, then probably. Start at 10A and adjust down until you get a reading that makes sense just don't adjust down lower than what you're reading.

Here's a break down of what you can measure under the DCA settings:

2000u = .002 Amps MAX
20m = .020 Amps MAX
200m = .200 Amps MAX

If the total draw on your camper is anything more than even 1/2 an amp you're going to blow your meter.

If you set it to DC 10A you can measure a MAX of 10A. It's pretty likely the total draw with everything on is going to be more than that, which means that once again you'll be blowing your meter.

[fivonut]

Yes , run it is series (inline) to measure the current draw. Be careful no to touch the leads to anything but the battery terminal & the lead; and like Coooooooooop said, start with the 200m DC setting in case you get a rush-in current that'd be too high for the 20m DC setting.

Usually the smaller settings (like those in the green box) are non-fused. I'd start at 10A and work down. The 10A setting (right side black) is probably fused which will save the meter if your amperage is higher than you expect.

[fivonut]

If the total draw on your camper is anything more than even 1/2 an amp you're going to blow your meter.

That should read 1/4 Amp.

(It sucks that I can't edit my post, what a waste of bandwidth:goof:goof)

[badass88gt]

So if I want to measure the total draw of the electronics in the camper, I'm SOL. Goddammit.

[Windsors 03 Cobra]

No you are not SOL you just need a bigger capacity ammeter, may I recommend a automotive style dash mount ammeter of the 60 or 100 amp variety ?
They also go right inline and cost about $20 at an auto parts store.

[Moparjim]

Also be sure to switch your red positive lead over to the other terminal that says DC 10A. If you need to measure more than 10A, like others have said you will need a new tool. You should be able to get a clamp on probe that will work with your current meter...

[DurtyKurty]

Inductive amp clamp FTW!

Dash Mount Amp meter FTL! There is a reason they started putting voltmeters in the dash.

[BAD LS1]

Amp clamp or a DC shunt using a Mv scale will show the draw in amperage... Obviously 0 amp draw is best, but even a thenth of an amp (.1) will drain a battery in a matter of weeks. Most newers cars have about a 1 amp draw at all times for RAP

The Briggs DC shunt i use will allow your 10A meter to read up to 300 amps!! It clamps on the negative terminal, you hook your meeter into 2 points on it and because of the known resistance of the gap between the to leads, the meter will do the ohms law calc on Mv and display DC Amps. It will allow up to 300 A DC because it looks inside the system, just like the amp clamp,instead of charging through the meter or aka hooking the meter in series.

The shunt is more useful for testing charging system output and starter amp draw etc... If your careful, the above listed method with hooking it in series can work, crude but can work... but eliminates showing other possible issues that could be with the + cable that is now not attached to the batt etc... DO NOT TURN ANYTHING ON IN THE VEHICLE IF YOU DO IT THIS WAY!! If you draw more than 10 amps , the meter fuse will pop for sure or the meter will be ****ed. just use it to look for draw... i straight up dont like this method, but i guess it can work for a quick test.

[fivonut]

Inductive amp clamp FTW!

Dash Mount Amp meter FTL! There is a reason they started putting voltmeters in the dash.

We use an inductive clamp at work to measure output of our welders. It reads 425A +/- pretty well. They aren't cheap!!!

[Heat Seeker WS6]

We use Fluke inductive ammeters at work & damn gotta love 'em!
'Buy' one from someplece and then return it when done :thumbsup

[BoosTT]

First things first... Your meter would nearly explode if you tried to mesure the current with it, as is. Look at the gauge of the wire on the meter vs. the camper. That alone should tell you not to even think about it. You could meausre the voltage drop, but that wouldn't do much good.


You have some options:
-Get a reduced probe for your meter (usually drops the amperage by x 10).
-Get a clamp on current meter... $150
-Make a plug in line fuse holder and buy several different size fuses to see what blows and doesen't. This could be done for less then $5, and could be used for other things or as a extra in line saftey fuse. I would look in car audio for these....

[Reverend Cooper]

the fluke i have will work for you dan that one will blow the fvck up

[badass88gt]

What the fluck is a fluke?

[Reverend Cooper]

can handle larger cotages,i would just get the 20$ gauge if it was me

[Windsors 03 Cobra]

Fluke=name brand of test instruments, industry standard and big $$$.
I got a very nice, very new looking basic fluke 77-3 off a crackhead for $7 last summer, I also have blue point and greenlee dvoms in addition to an old Simpson 260 with roll top case.
An old wiggy is my most used electrical tester.

[fivonut]

All of the Fluke 77's we have at work can only measure max of 10A.

[Windsors 03 Cobra]

The $20 dollar Isspro ammeter in my Mark VII goes to 100 amps. :thumbsup