Digitech Multimeter to measure amps not voltage

Submitted: Friday, Mar 06, 2009 at 15:23
ThreadID: 66566 Views:11913 Replies:8 FollowUps:11
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Hi all
Don't understand the whole elec thing much but can i use this multimeter to measure the amps in the battery . Voltage reading is fine.
Thanks
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Reply By: farouk - Friday, Mar 06, 2009 at 15:37

Friday, Mar 06, 2009 at 15:37
Hi Findanomad,
Yes you most certainly can use it for measuring amps. Just change the red lead over to the amp socket at bottom of multimeter then change the switch over to the number 10 or maybe it is 20 on your meterwhere it indicates a A then a straight line with dots under it.. Then if you are wanting to measure the amps going in to a battery from a solar panel or wharever just put the red lead on to the battery terminal and the black lead on to the end of positive wire coming from panel and presto you have the number of amps coming from your panel.
Farouk
AnswerID: 352565

Reply By: _gmd_pps - Friday, Mar 06, 2009 at 15:59

Friday, Mar 06, 2009 at 15:59
no you can NOT measure the amps IN a battery. you can only measure amps flowing when a load is connected. What you want is a battery monitor which monitors amphours charged and taken out. they are a bit more pricey than a multimeter.
good luck
gmd
AnswerID: 352573

Reply By: peteC - Friday, Mar 06, 2009 at 16:03

Friday, Mar 06, 2009 at 16:03
Dont put the meter straight across the battery you will probably put a few thousand amps thru the meter and end up with a blown fuse or ( as some meters are not fuse potected ) you will have a nice smoldering molten mass of plastic in your hand. You use the amp measurements to show how many amps a device uses when operating. eg a 5 watt 12volt bulb will draw 0.42amps. The formula is Power ( in watts ) = voltage x amps. To connect the meter it must be in series with one of the cables, not across both cables as you would when measuring voltage.
AnswerID: 352576

Follow Up By: Member - Cram (Newcastle NSW) - Friday, Mar 06, 2009 at 16:06

Friday, Mar 06, 2009 at 16:06
I have not even started drinking but I am already seeing triple...lol
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FollowupID: 620762

Follow Up By: Member - Warfer (VIC) - Friday, Mar 06, 2009 at 16:11

Friday, Mar 06, 2009 at 16:11
Petes always had a Stutter ! lol
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FollowupID: 620764

Follow Up By: farouk - Friday, Mar 06, 2009 at 16:28

Friday, Mar 06, 2009 at 16:28
Well howsabout that!!! Either I am not very good at explaining myself or I am blessed but I have been using this method for 17 years to measure input from a loose solar panel and would you believe I have never had a problem with the multimeter. You may or should I say WILL get a problem if you leave it hooked up permanantly but for a quick check I have been getting away with my method OK. Have also used this method to test input from alternator on Cruiser by putting meter in between positive cable to battery and the battery and for some unknown reason that has worked and so does the Multimeter. Farouk
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FollowupID: 620767

Follow Up By: Member - Phil G (SA) - Friday, Mar 06, 2009 at 19:18

Friday, Mar 06, 2009 at 19:18
Farouk,
Ammeters are connected in series, and this is what you've correctly done for 17 years. Pete is referring to having a multimeter (on the unfused 10amp setting) and accidentally putting one lead on a battery pos, and the other lead on neg. It kills the 10amp part of the multimeter every time!
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FollowupID: 620804

Reply By: _gmd_pps - Friday, Mar 06, 2009 at 16:33

Friday, Mar 06, 2009 at 16:33
no you can NOT measure the amps IN a battery. you can only measure amps flowing when a load is connected. What you want is a battery monitor which monitors amphours charged and taken out. they are a bit more pricey than a multimeter.
good luck
gmd
AnswerID: 352585

Follow Up By: Member - Warfer (VIC) - Friday, Mar 06, 2009 at 16:46

Friday, Mar 06, 2009 at 16:46
I was always under the impression that you can only measure the flow rate as such...



Cheers
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FollowupID: 620770

Follow Up By: farouk - Friday, Mar 06, 2009 at 16:52

Friday, Mar 06, 2009 at 16:52
I have a problem finding in original post where the question was (amps in a Battery) I am sure that what was wanted was Can I measure amps as well as volts and the answer is YES following the procedure I used in previous post
Place the multimeter INBETWEEN the POSITIVE lead coming from whatever and the Battery which will give you INPUT or CHARGE from panel to Battery.When you want to measure how much your TV is drawing remove Positive lead from battery and place BLACK wire of mulimeter on POSITIVE terminal and the RED wire on the end of cable you have removed from Battery for discharge. It really will not matter a lot if you have the leads from Multimeter around the wrong way as multimeter will show either a + or a - alongside of the digital readout. Of course there is a limit on how many amps can be run thru the meter , if it is a 10amp well that is the limit.Farouk
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FollowupID: 620775

Follow Up By: _gmd_pps - Friday, Mar 06, 2009 at 19:03

Friday, Mar 06, 2009 at 19:03
quote: "the amps in the battery"
what part of IN do you NOT understand
need better glasses ?

have fun
gmd
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FollowupID: 620803

Follow Up By: farouk - Friday, Mar 06, 2009 at 19:37

Friday, Mar 06, 2009 at 19:37
You are right GMP and I apologise, I am afraid I read the post incorrectly and obviously you were right I read only " you cannot measure amps" and did not read the rest, the glasses are ok but there is a problem elsewhere!!!
Farouk
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FollowupID: 620807

Reply By: Ozboc - Friday, Mar 06, 2009 at 17:43

Friday, Mar 06, 2009 at 17:43
just for the record - you can bvuy cheap Clamp meters ( used to testing amperage draw in a circuit easily and cheaply) on ebay - if you by locally you can expect to pay about $100 and upward to about $300 for a known brand name

I just ordered one from HK $26 + free delivery - a good option if your only ever going to use it occasionally - i use mine for work and they tend to go walk about - hence the cheap nasty

Hope this helps

clamp meter on ebay

AnswerID: 352596

Follow Up By: Member - Kiwi Kia - Friday, Mar 06, 2009 at 18:00

Friday, Mar 06, 2009 at 18:00
Ozboc is right.

You can now get real cheap clamp meters to measure DC current completely safe and idiot proof. Got one last week for $15 to demonstrate the huge current when winching.

Findanomad - Ring Jaycar, Repco, Supacheap etc and ask if they have DC clamp meters. I think Jaycar had them for around $120 and DickSmith had them for about $100. I got mine from The Warehouse for $15.

.
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FollowupID: 620792

Follow Up By: Ianw - Friday, Mar 06, 2009 at 21:57

Friday, Mar 06, 2009 at 21:57
This one will NOT read DC amps !!!! AC only !! DC ones are quite a lot more expensive.

Ian
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FollowupID: 620827

Follow Up By: Member - Kiwi Kia - Friday, Mar 06, 2009 at 22:07

Friday, Mar 06, 2009 at 22:07
Well spotted Ian. But there are dirt cheap DC clamp meters around now that are ideal for heavy current like battery starting and winching. I have compared my $15 cheap one with a 'brand' name meter and the difference in the current reading was not worth worrying about.

.
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FollowupID: 620832

Reply By: Member - Mike DID - Friday, Mar 06, 2009 at 19:31

Friday, Mar 06, 2009 at 19:31
You can measure the pressure (voltage) from a pump by tapping into the line.

If you want to measure the flow in litres per minute (amps) you have to interrupt the line form the pump.

You can't measure the tanks capacity in litres (amphours) by connecting to the pipes on the the tank.
AnswerID: 352610

Reply By: Member - Phil G (SA) - Friday, Mar 06, 2009 at 19:37

Friday, Mar 06, 2009 at 19:37
MrNomad,

Good question. It can get confusing. It boils down to what information you want.

Your multimeter most likely has a couple of ways of measuring current (amps), and its best to have some idea of how many amps you're going to measure. Remember amps is always measured in series (i.e. use the multimeter like a piece of wire - never hook it up to both pos and neg sides of a battery)

With the multimeter leads in the same sockets (as you are using for volts), it will probably measure up to 0.2Amp (200 milliamps). This is not much current and is useful for measuring the current consumed by a circuit board, or a relay coil, or a battery isolator, or low voltage cutout etc etc

The 10amp setting requires the red lead to get moved to the third (unfused) socket. This is useful for measuring the current being used by a fridge or a light, or any other accessory that uses less than 10 amps.

If you want to measure more than 10amps, you need a new device. Either buy an ammeter that measures more (eg 20amp, 60 amp or whatever and hook it up, or if you want a spot reading, many prefer to use a clamp meter.

If you want to measure high amps continuously (eg you want to know how many amps are going into your aux battery) you will want to install a "shunt ammeter". This is not a true ammeter - it is actually a voltmeter that measure the small voltage difference across a small resistance (shunt) and translates that into how many amps is travelling thru the wire. That is the way most vehicle ammeters work.
AnswerID: 352613

Reply By: Mick15 - Friday, Mar 06, 2009 at 20:11

Friday, Mar 06, 2009 at 20:11
If you wanna see what kinda capacity your battery has - what kind of current it can put out, just go to a car battery place and they will load test it - basically put a load across it and see how it copes as the load is gradually increased.
Ideally this should be hundreds of amps something like the cca rating, might be 50% of the cca and just turn the car over, not much room for error though.
AnswerID: 352622

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