Is there a DC clamp meter with amp-hour counting?

[isso]

Hi, I often need to check a capacity of a battery during charge or discharge. It's very convenient to use a clamp meter to measure the DC current, because there's no need to break the existing wiring. But to measure the amount of energy I need to multiply the DC current by the time passed, and if the DC current changes over time, this becomes a hard task. Is there a clamp meter model that can do the calculation of amp-hours automatically?

[Someone]

"coulomb counter"

But if it's attached to monitor continuously what's the value in a clamp? All the normal coulomb counters I'm familiar with use a current shunt resistor.

[isso]

Yes it's "coulomb counter", thank you for suggesting the correct term. Sorry I didn't get your question, I basically need to count the amount of energy flowing through a wire in some period of time without modifying the circuit (i.e. shunts don't work for me). So I thought a clamp meter with a counter (integration option) would work the best for me.

[ledtester]

This product is described as a:

"Charge-Discharge Monitor, DROK 0-90V 100A DC Ammeter Voltmeter, Battery Capacity Amp-Hour Watt-Hour Power Time Multimeter, LCD Display Digital Voltage Current AH WH Watt Meter Tester with Hall Sensor"

https://www.amazon.com/Charge-Discharge-DROK-Voltmeter-Watt-Hour-Multimeter/dp/B07YWVCBRN/

On Aliexpress the search terms "DC power meter hall" seem to come up with what you're looking for:

https://www.aliexpress.us/w/wholesale-dc-power-meter-hall.html?spm=a2g0o.detail.search.0

also "DC coulomb meter hall":

https://www.aliexpress.us/w/wholesale-dc-coulomb-meter-hall.html?spm=a2g0o.productlist.search.0

[isso]

Thank you very much for the links, I have a couple of those devices, there are a few problems with them - they aren't technically clamps (I need to clamp to the existing wiring), their accuracy is quite bad, and they aren't really hand tools, i.e. they need housing, power supply etc.

[modoran]

There are real clamp meters that output a voltage instead of direct reading, maybe you can use one of those.

[Pfriemler]

... their accuracy is quite bad...

Isn't that the case with any (dc) clamp meters? I only use them to get an idea of flowing current instead of measuring them. One of my two is a cheap Voltcraft with useless readings if the current exceeds the measuring range only for a second.
And in some cases you do not need to insert a shunt, if you can get a voltage along an existing cable.

[isso]

There are real clamp meters that output a voltage instead of direct reading, maybe you can use one of those.

Yes I'm leaning to that option, although I was hoping there would be an off-the-shelf device I could buy...

[isso]

... their accuracy is quite bad...

Isn't that the case with any (dc) clamp meters? I only use them to get an idea of flowing current instead of measuring them. One of my two is a cheap Voltcraft with useless readings if the current exceeds the measuring range only for a second.
And in some cases you do not need to insert a shunt, if you can get a voltage along an existing cable.

Yes the clamp meters are much more accurate, I have an inexpensive UNI-T UT210E device that is way more accurate than those battery capacity meters. I guess more expensive clamp meters will have even better accuracy.

[Pfriemler]

There are real clamp meters that output a voltage instead of direct reading, maybe you can use one of those.

For DC? The TO wants to monitor a battery discharge. I wouldn't consider DC clamps at all for that purpose.
For AC, it's easy to get any kind of transformer around a wire, see the Shelly clamps of the three phase power meter.
With DC, it's a lot more complicated to get offset-free readings for a long time.
In other words, it's easy to zero a reading after clamping a wire with no current, and then switch the current on and get an more or less accurate reading. But do not expect an accurate longtime reading (for hours).