LifePo4 battery at 13.49 volts, but 12.7% Capacity??

[jdege]

Now the volt reading isnt that accurate. Its about .1 to .2 off most of the time compared to a real volt meter. But the state of charge, time till empty/full and amp readouts are dead on with mine.

I was just watching a video where a guy was testing a $10 meter. He had four different meters he was comparing, and they all differed by 1 or 2 tenths.

The monitor may be right and your meter wrong.

If you care about tenths, you need a quality meter, and you need to keep it calibrated.

 

[Tomthumb62]

Thats a bit weird in that I only had 400 to 800 mA load on the renogy for a few months and it worked fine showing discharge and charge.

From what I have read elsewhere the wifi renogy and their other products shunt wise suck at measuring accurately but the wired one I linked to is pretty accurate from what I had read and from my experience.

TIL. I didn’t even know that Renogy had other battery monitors than the wired one. I always assumed that whenever someone referred to the Renogy battery monitor, they were speaking of the one you’re talking about.

 

[wholybee]

You need a real charger, that is your only issue. An absolute minimum would be 5 Amps, 20 would be better. The battery tender is meant to maintain a battery at full charge while in storage, not charge one. (And it is highly recommended not to do this with LFP anyway).

Cheaper monitors have a dead area around 0 Amps so that a meter will not slowly drift while no current is actually flowing. That dead zone would be a few milliamps though, not 400 or 800. Better meters like the Victron have a zero current calibration. Bluetooth or no makes no difference. It is all in the quality of the electronics and accuracy of the shunt itself.

 

[Crowz]

I was just watching a video where a guy was testing a $10 meter. He had four different meters he was comparing, and they all differed by 1 or 2 tenths.

The monitor may be right and your meter wrong.

If you care about tenths, you need a quality meter, and you need to keep it calibrated.

Im pretty sure the $300 fluke is more accurate than the renogy

 

[jdege]

Im pretty sure the $300 fluke is more accurate than the renogy

It will be, for some months after it's last calibration.

When did you last calibrate it?

 

[Crowz]

It will be, for some months after it's last calibration.

When did you last calibrate it?

The one I used when I tested that was a test calibrated 2 years ago and was actually adjusted 37 years ago. The newest fluke I have used one it isnt but 4 months old. Both were within the hundredths of each other.

The one I use to test with all the time now is a $20 meter I got off amazon. I VERY rarely use the flukes now as they are from my stepfather who passed away not long ago and I value them more for that reason than as test equipment. Basically if Im going to risk damaging/misplacing/lose thru friends something I dont want it to be them and would rather risk the cheapo ones from amazon. Plus none of my flukes have backlights and at my age I find that a very important and often used "feature"

 

[jdege]

When I use a meter it's almost always either checking for continuity or searching for voltage drops.

I neither case does it matter whether the meter is calibrated.

 

[Dazed and Confused]

Well…..
That escalated quickly.

This got waaaay more technical than I expected.
I think I’ll just let it play out with my ‘current’ (get it?) setup and let the chips fall where they may.