Home › Forums › Mooshimeter Support › Loggining DC current and voltage at the same time
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Need help here.
First, let me clarify that I have no background in electronics so I do not understand words like “SHUNT”, “RELAY” ETC.
I am running a project to record the voltage and current of a bike battery while it is bing charged by a trickle charger. The voltage data shown is fine but I am not able to get the current data. I have tried options of putting the banana clips in “A” and ohm. No effect.
Please, I need step by step method to record both current and voltage at the same time.
Again please consider me to be a moron , so detailed steps will help…
I can send you a drawing as you have to connect the Mooshimeter. For this I need to know how much current the charger has to ensure sufficient measuring range from 10A of Mooshimeter. On the power supply voltage in V, a current in A or a performance in W must be specified. Slice me this information and you make a drawing.
The charging current is up to a maximum of 5 amps. I didn’t get the rest of it. Do you want me to make you a drawing of the setup? I can do that.
Same connection should work.
If you see negative currents, you can swap leads from A and C connectors.
There is little possibility that you have already blown mooshimeters fuse, but lets hope not..
I might add that I am not able to see the current readings in single mode also. Voltage, however, is fine. Does this mean a fuse issue? I hope the fuse is replaceable. Any details on the fuse I need to get.
Mighty cad-skills ;)
Quick & dirty way to test if current-fuse is ok: measure some voltage by connecting leads to A and V connectors. If voltage is ok, then fuse has to be ok. If you can’t see anything, fuse is gone.
Fuse on my mooshimeter says “reomax 632.300 12A”. James had those on his webstore at some point (can’t find it now), but you should be able to buy similar fuse locally, but you have to be sure that you buy fuse that is meant for multimeter. You don’t want to blow up your eyes and your multimeter with cheap ones..
Sorry for the late reply as I was not sure if the fuse was gone. I followed the Mooshimeter manual and it said that if the resistance is less than 0.5, the fuse is fine. I reading I get is close to 0.3
Now first thing, if I try to measure the current alone it give me values like -0.00 whereas the standard meter measures at 0.02 Amp. Second I think I need to modify the diagram as the positive and the negative from the charger come out as one lead and then separate. The charger body is made of plastic so I am not sure I can connect the C to the body of the charger.
So 3 questions:
– Is the fuse OK?
– Why the meter is not reading current in single mode
– And what to do next?
@James and Deepak
There is an error on that fuse test text in mooshi-manual.. “Figure 8” below it is right, so you need to measure between A and OHM. And in my opinion, that straight line from ohm to A may be misleading at first sight and wider loop of test lead around the meter (with maybe couple of knots ;) ) would be closer to real life and we might understand what it tries to show :D
I was too quick to come up with my own solution and told you to measure some voltage, that resistance measuring is of course the right way to do it.
So i can’t yet tell if that fuse is blown or not, as i don’t know which one of those instructions has been used..
– I checked continuity of the fuse and it failed. So it is blown. So need to wait till I get a new fuse.
In the mean time I understood your diagram. I will work on it once the new fuse arrives. One note that I had to place the V on negative and A on positive for it to read the voltage properly.
Thanks a ton for your help till now. Sorry but will bother you once I get the fuse. Need to complete the project.
Sounds like a way to blow a fuse, if you had more than two test leads connected while measuring voltage with A and V connectors.. Now without intact fuse, negative path from charger to battery is broken, so anything connected to A is just same as if it is not connected at all.
Now, with broken fuse, if you have everything connected like in your diagram with my additions, charger wont “see” battery at all and may refuse to show any voltage. In that case, if you change test leads between A and V (what you are not supposed to do), you probably see some voltage, but it depends on charger what you will actually get.. If you got “proper” voltage that way, i’m pretty sure there is something wrong, as i would expect close to zero or few volts when charger is on and negative battery voltage when charger is off (or thinking that there is no battery)..
Even as electrician, i don’t like to measure current with multimeters.. It is so easy to screw up and blow a fuse. And with two channels in one device, you have to be even more careful. And then there are idiots like me, who tell other people to check their fuse a bit wrong, which does not help :D .. At least i should have said that you cant have anything else connected while doing it.
I am back.
Finally I got the fuses and a big thank you for the support. It worked! I was able to measure the current and voltage at the same time
Another issue though. I tried measuring the current alone by connecting A to the positive of the battery where the positive of the charger connects and connecting C negative of the battery where the negative of the charger connects. There were sparks and the fuse was blown.
How do I measure current alone. If you want I can show off the CAD skills again!!
You cannot measure amperage of just a battery, you just did a shortcut!
There has to be “source – meter – load” path for you to get measurable amps.
Quick googling gave this:
You should take few minutes and check that..
I also have the same issue of possibly blown fused, measured continuity of the fuse by connecting the positibe to the fuse side and the other side to positive led, it does not light up.
May i know if any fused 12 amperes shall be working with this multimeter ?.
What are the equivalant that i should consider in order to get the fused.
It is hard to get the same brand in my country.
I would like to also check how could i measure higher amperes. It stated that shunt. I am not sure and unable to get elaboration of the shunt.
If i operate without fused for testing low amperes, i use aligator clip and tap on the fuse clip on moshimeter so it is series why i unable to display the amperes
Please email me at email@example.com with a shipping address and I will do my best to help, either by finding an equivalent fuse, a local distributor, or by shipping directly.