question

The charger settings look right.

The SmartShunt settings look ok.

The SmartShunt has automatically synced the battery properly. Battery voltage > 13.2v + current < 2.16a for 3 minutes.

There is just the oddness of the -72.8 Ah drawn from a 54Ah battery. It is also odd that an 18a charger can charge the battery 53.1Ah in 32 minutes??????

The anderson plugs are for the Orion's power input?

Puzzling.

Hi @itllgrowback

Make sure your Smartshunt is never powered down. This may go against the grain in a 'truck', but it needs continuous power. Not much though. If it's been powered down it will need to see a realistic sync to be of any use.

The Consumed Ah figure is actual, as measured from the last sync to 100%. This isn't adjustable via calibration. If it's wrong the unit is faulty. This doesn't apply to the Ah 'counted back' under charge, as it must be adjusted for Charge Efficiency to give a realistic figure.

How you get 72.8 Ah from a 54 Ah battery I can't explain. Maybe the batt is capable of more, down to a lower V where it's not supposed to be?

I don't think your settings have caused this. Not to say they're all suitable. I'd raise the Charged V up to say 14.2V (0.2 below Abs), as 13.2V risks false syncs. The 1.05 Peukert is probably ok, but if you want Ah to match SOC then set it to 1.0.

Your charged voltage setting of 13.2V is far too low and as a result will always report 100% early.

My 4 cell 300Ah LiFePO4 battery is set at 14.1V.

Might also be worth selecting battery current and voltage under trends tab. This will log 45 days worth of the selected settings. Might give you additional clues.

@itllgrowback

10:50 to 10:53 is three minutes. Your charge detection time is 3 minutes. So not random. It synchronised then because of your other settings. If your settings are close to perfect for your batteries you will see amost no synchronisation to get to 100%.

As is mentioned charged voltage is set too low in your settings. It must be higher than float but not as high as the absorption voltage.

Also, i know lifepo4 say they are 99% but in reality i have not seen that. So you may need to adjust that.

I have some results to report - @JohnC , @Alexandra , @klim8skeptic - if you're still interested, this was interesting to me:

This morning I ran a test with a known load - two spotlights from an old install. Together, the Shunt is reporting they use roughly 9.1A (unfortunately, my Fluke's 10A fuse has blown at some point so I was unable to verify that current externally - I can test that tomorrow when a new fuse arrives, and it'll be interesting to see if the Fluke reports the same current as the shunt does).

But, what I observed over a two-hour steady discharge and a two-hour steady recharge, is a predictable discharge/recharge in this test, and accurate SOC numbers. The charger I plugged into the unit to recharge it is from Dakota, and was charging at roughly 9.2A, almost the same rate as the lights discharged the battery - that's entirely coincidental, but it resulted in the experiment taking almost exactly the same amount of time to recharge as it did to discharge. More to the point, though, the SOC behaved exactly as you'd expect:

So then the question becomes, why am I getting such odd results in my actual use case? Again, that's a Dometic CFX55IM Fridge, powered by the battery full-time, but whose compressor runs only intermittently. Then the charger also runs intermittently when the truck is running and the Orion-Tr senses the alternator is pushing out amps. So it's much less direct than my experiment - things are discharging and recharging at different rates and periods intermittently throughout the day.

I'm currently running a new test, same as the one I did this morning, but with the Dometic plugged in instead of the spotlights. That'll take more time, because the fridge only uses some 3A, and only when the compressor is running - so it's not discharging as quickly. And when I recharge it for this test, it'll be with the Dakota charger again versus the Orion-Tr I that would be in play in normal use. I'll report back those results when I have them, but I might just let it run overnight to discharge further, and then charge it up tomorrow while I can monitor it.

Thank you for your help - I hope we can find out what's going on, whether something in my install or other.

Well, after running the fridge overnight, on its normal periodic on/off cycles, I discharged it down to 20%, which is about the lowest I prefer to let it discharge. Then, I plugged in the Dakota 10A charger again, and let it charge back up.

It took about 5 hours as you can see below, and though I didn't observe the synchronization in real-time (it happened before the hour mark, and I wasn't watching), it looks like everything behaved as you'd expect:

And so the question remains: what's going on in my normal use scenario? Everything in these tests seems normal, but in normal use things are wacky. So I decided to reset the history on the SmartShunt, and turned on the fridge again, with normal settings, and I'll log what happens in the week to come.

As a sidenote, I got a new fuse and tested the current with the Fluke compared to the Shunt, while the accessory spotlights were connected, and they were within a margin I'd consider negligible: 8.82A on the Fluke compared to 8.76A on the shunt in the same moment. So take that for what it's worth - I think it settles any discrepancy between the shunt and another device (but let me know if you disagree - I'm a hobbyist).

So I'll report back soon to let you know what numbers I see in the days to come, with the normal intermittent discharge/recharge cycles.