Anyone install this cheap coulomb meter?

Photobug

Well-known member

I got one of these to upgrade my solar generator.

How/where did you mount the shunt?

Does the shunt need to be protected from contact from other things?

I currently have my battery charger go directly to my battery, should the negative now be run to the negative bus to computeScreen Shot 2020-09-19 at 11.37.10 AM.png the power going into the battery?
 

Photobug

Well-known member
Here are photos of my power pack with the area I would like to mount this unit.

The two issues though. This are is where I currently store cables and chargers, etc to use with the power pack. It is also where I would like to install an AC battery charger when I find one I like that fits.20200919_112723.jpg20200919_112737.jpg20200919_112818_01.jpg
 

broncobowsher

Adventurer
As above, if you are trying to measure what is going in and out of the battery, you can't bypass that measurement device. If anything is connected directly to the negative post, that is a path to bypass the measurements.

Second, loose the wire nuts. They fall off from vibrations. They are fine for your house, not acceptable for mobile applications.

Yes, you should mount the shunt somewhere. It should not just be flopping around loose in there.

No, I have never used that before. The above is just good housekeeping for electrical.
 

Sneaks

Active member
I’m using two different brand but inexpensive meters and shunts - on for load, one for draw. Both shunts are located in the ground cable for the battery. Pay close attention to the instructions, the one I used require the earth for the gauge itself to be connected to the shunt, where depends on what direction of flow you are measuring. The hot lead needs to be on the same circuit (won’t be accurate if monitoring house but have gauge on vehicle hot) for the ones I used. Read instructions closely, reviews have some nuggets, too. Fortunately all the gauge wiring can be small, 18-22ga, but in my case had to run 8 of them 15”. Don’t have pics of the shunts as they are behind my house batt, but these are the gauges I used, they’re accurate when referenced against my DMM.

52edd67cb4d01fd36a7eee5c652a3c45.jpg



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Photobug

Well-known member
So I got it wired. RIght now the shunt is floating in the box until I figure out how and where to mount it.

One problem is I have a small wire attaching the B+ side to the positive bus. The first switch on my panel is to power up the hot bus. That way nothing can be drawing power from the power box until this switch is on. So in order to be monitoring the power I need to have the main switch on. I can move the wire to the battery lug but can't find will have to order a 3/8" bolt to fit with #18 wire or just use a wire that is bigger than needed to work with something I have on hand.

I turned on a few lights on the box and it shows the amps being used with a negative sign so it shows amps are going out. I will test later by charging it and see if it shows a positive sign for amps going in.
 

Photobug

Well-known member
Second, loose the wire nuts. They fall off from vibrations. They are fine for your house, not acceptable for mobile applications.

Yes, you should mount the shunt somewhere. It should not just be flopping around loose in there.

The wire nuts are just on the external LED lights, all other wiring is using marine grad wires and heat shrink crimps. I will clean this up eventually when I finish I fit the final piece of this unit an AC battery charger.

I have every intention of mounting the shunt, my question is how and where. The unit does not lend itself well to mounting, there is no structure or mounting plate and the plastic of this box is very difficult finding a way to adhere to.
 

Sneaks

Active member
You can’t drill through the box anyplace to run the studs through? If not, what I did with one of mine (the other is attached by the studs) is used a scrap piece of .5” thick plastic, countersunk the studs heads, then used 3m double-sided tape to attach to side of my battery box.


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IdaSHO

IDACAMPER
With proper battery cables you shouldn't have to mount it.
How about a short cable and double stick foam tape on the backside of the shunt, stuck top the top of the battery?

No matter how you do it, I would wrap/coat it with something non-conductive.
Liquid electrical tape would work well. Just apply it, a few coats, after all your connections have been made.
 

Photobug

Well-known member
With proper battery cables you shouldn't have to mount it.
How about a short cable and double stick foam tape on the backside of the shunt, stuck top the top of the battery?

No matter how you do it, I would wrap/coat it with something non-conductive.
Liquid electrical tape would work well. Just apply it, a few coats, after all your connections have been made.


No need for any large battery cables. I have limited this boxes output to 30a based on fuses and 10 gauge wire. If I get larger crimping capabilies maybe I will upgrade the cable size.

Does the Liquid electrical tape peal off if I want to repair or upgrade cable size later?
 

Photobug

Well-known member
You can’t drill through the box anyplace to run the studs through? If not, what I did with one of mine (the other is attached by the studs) is used a scrap piece of .5” thick plastic, countersunk the studs heads, then used 3m double-sided tape to attach to side of my battery box.


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I have avoided it so far but am about to start drilling through the box to mount the battery, every other attempt around this has failed.I could drill through but then end up with two big ground bolts sticking out of the box. I have thought about the plastic scrap method you mentioned if I only had a 1/2 thick plastic sitting around.
 

Sneaks

Active member
Piece I had was leftover from a better half’s household project, got it at Michael’s but probably could find it at just about any craft store. Wood would also work
 

Photobug

Well-known member
Piece I had was leftover from a better half’s household project, got it at Michael’s but probably could find it at just about any craft store. Wood would also work

Thanks I am 2 hours from the nearest craft store. I got no shortage of wood. Not sure it is kosher to put wood into an electric box.
 

Sneaks

Active member
Thanks I am 2 hours from the nearest craft store. I got no shortage of wood. Not sure it is kosher to put wood into an electric box.

Sounds like where we are, craft store is about 2 hours away, same distance as any of the box stores, hell, closest grocery store is over an hour away in summer, almost 90 minutes once the white stuff falls. Wood is non-conductive, look where your home breaker box is mounted :).


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Photobug

Well-known member
Sounds like where we are, craft store is about 2 hours away, same distance as any of the box stores, hell, closest grocery store is over an hour away in summer, almost 90 minutes once the white stuff falls. Wood is non-conductive, look where your home breaker box is mounted :).


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Wow you are out there. All 3 grocery stores in my town are a 15 minute walk or less but if I wanted to buy some cotton sox I got to drive 2 hours.
 

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