"Bob Engelhardt" wrote in message ...

On 1/13/2021 3:06 PM, Jim Wilkins wrote:
[snip] I think as a rule the maker clearly tells you if a
product can read RMS, otherwise assume it reads Average.
...
You're right, of course. What maker is going to go to the trouble of
including a desirable feature without mentioning it? They would boast
of it.

That meter is so attractive for its functionrice ratio that I couldn't
help but hope that it was RMS.

Thanks, Bob

--------------------------

I checked the 100A AC version, PZEM-061, against a Kill-A-Watt with a
refrigerator load and it matched the KAW's Watts display, so it reads RMS.
The KAW's VA reading was substantially higher.

I haven't used the 100A DC meter very much because my battery application
really needed a meter that shows + and - current. The 20A version is fine on
pure DC test current until it wanders out of calibration, possibly due to
the dawn and dusk fluctuations of solar panel voltage. On pulsed current in
or out of a PWM or MPPT solar controller none of my meters agree.

The important questions are if a battery is fully charged and how long it
will run my refrigerator, and unlike with Lithiums tracking the charge and
discharge currents doesn't seem to answer that well enough, because other
factors interact. The meters just show if things are or aren't working
right.

The SIN9020S battery fuel gauge I'm testing now is "currently unavailable".

A 1" PVC conduit tee makes a good insulated housing for the 100A shunt.

"Jim Wilkins" wrote in message ...

I checked the 100A AC version, PZEM-061, against a Kill-A-Watt with a
refrigerator load and it matched the KAW's Watts display, so it reads RMS.
The KAW's VA reading was substantially higher.

-------------------------

Correction: it reads real power, not necessarily RMS.

On 1/14/2021 10:56 AM, Jim Wilkins wrote:
....
I haven't used the 100A DC meter very much because my battery
application really needed a meter that shows + and - current. The 20A
version is fine on pure DC test current until it wanders out of
calibration, possibly due to the dawn and dusk fluctuations of solar
panel voltage. On pulsed current in or out of a PWM or MPPT solar
controller none of my meters agree.
...

It's winter, there's a pandemic, so you're stuck in the house and what
you need to do is build the meter that does exactly what you need it to
do. Can't be that hard? Just an Arduino and some code ... Bob's your
uncle. BG

"Bob Engelhardt" wrote in message ...

On 1/14/2021 10:56 AM, Jim Wilkins wrote:
....
I haven't used the 100A DC meter very much because my battery application
really needed a meter that shows + and - current. The 20A version is fine
on pure DC test current until it wanders out of calibration, possibly due
to the dawn and dusk fluctuations of solar panel voltage. On pulsed
current in or out of a PWM or MPPT solar controller none of my meters
agree.
...

It's winter, there's a pandemic, so you're stuck in the house and what
you need to do is build the meter that does exactly what you need it to
do. Can't be that hard? Just an Arduino and some code ... Bob's your
uncle. BG

------------------------------
I would need better A/D sensitivity and resolution and NOT one common ground
for what I'm doing. It's working pretty well right now with homebrew
discrete analog power circuits and diode switching 'logic'. Unfortunately I
haven't found inexpensive UL-rated substitutes for the modules I can build,
but not sell.