SOC% safety option?

[cybermaus]

Hi Guys

sorry for having so many questions about the SOC% in recent weeks.
Not been on this forum for months, and now every other day. Almost feels like spamming, but the matter is important to me.

I had something odd happen again, and it made me wonder:

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Sunday I did a full power down of the Classic, to reset the local app connectivity. As a result, the SOC% value went back to a blinking 100%. This I can understand: the Classic was fully off, so does not know if maybe a lot of current was used while it was off. (for reference, it was at about 65% just prior to the shutdown, so maybe a blinking 65% would have been better?)


Thing is: Aux1 remained high. One could argue that a safer action would be to also turn off Aux1 during moments of SOC% uncertainty.
Suggestion 1 : Blinking SOC% maybe should means Aux1 off?

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I switched to shore power with an external manual override switch.
Next day (yesterday) was a day with weak sun. Before I reset the Classic, it was at 65%, and according to the days Ah count, it maybe charged 10%. But the SOC% went from blinking 100% to non-blinking 100% !

Not sure why it stopped blinking, not sure if I can recreate that. But I am certain it would not have reached float or absorb.

And my sister, as per instruction, interpreted the non-blinking SOC% as command to turn off shore power again. Overnight it discharged 20% so the displayed SOC% dropped to 80%, but actual state more likely was now at 55%  (65%+10%-20%).

And to my surprise, SOC% was also blinking again.... It was blinking 80%.

Question 1 : Is there some safety build in? Like if the SOC% counter states 80% but the voltages are clearly too low (23.8V at 8A current draw) does the SOC% go back from non-blinking to blinking?

If so, I applaud that. Very good!
However, Aux1 still remained on. So maybe Classic did judge the SOC% doubtful, decided to blink it again, but Aux1 remained on.

Repeat Suggestion 1 : Blinking SOC% maybe should mean SOC% driven Aux1 off?


Thanks

[boB]

Suggestion 1 : Blinking SOC% maybe should means Aux1 off?

Repeat Suggestion 1 : Blinking SOC% maybe should mean SOC% driven Aux1 off?

Thanks

Great idea !   This will be done.


Not sure why you had some other happenings but will look into why it went solid but no,
there is no smarts to change to blinking when voltage goes down...  Unless ?  Nahhh...

boB

[cybermaus]

Great idea !   This will be done.

Perfect!

...there is no smarts... Unless ?  Nahhh...

Well, I can understand that you are cautious treading there. Though dropping to 1.98V/cell at practically open circuit surely is hint of not-being-full, even this noob agrees you can't properly determine SOC from voltage, and trying/pretending to do so in a product will only give disappointed customers.

Maybe you could at least build in some rock-bottom threshold. Sometimes I see equipment using 1.75V/cell (21V) as rock bottom, sometimes 1.8V/cell (22.2V). We would never reach that, we never let it go lower then 23.5V. Also, our inverter refuses to work below 22.2V anyway. But it could be an idea.

Also if it was at xx% percent before power-cycling, starting at a flashing xx% rather then flashing 100% could be a nice touch.

[cybermaus]

Another crazy idea:

because I have an under-powered solar array, it will not reach float every day. Current early spring ratio is about 2½:1 (3 days shore power, 2 day battery power). Last summer we just reached 1:1 on good days.

At the default 50%/90% Aux1-SOC% settings, it would never reach float, and after days of going up and down between those two borders, it would have wandered of quite a bit.

To avoid this, I attempt to force a re-set of the SOC% by setting the high value to 99% and putting CEF a little too low. So normally SOC is estimated a tad too low, and when it reaches float it re-sets SOC% to 100% and I start using battery again in the certainty it had a good reference point.

Would it be an idea to allow the Aux1 SOC% high settings to also accept charge mode in stead of a percentage. So if SOC sincs to 50%, go off (like current implementation), but during rising it checks the charge state, and when reaches absorb (or float), go on again.

When setting high parameter, it is as if absorb and float would be higher numbers: 96..97..98..99..ABS...FLT

Right now, I am forcing this with my 99%+low CEF trick. But that waits till float, and I was thinking system efficiency may be better if I already go active on absorb.


Do not hesitate to shoot down this idea if you feel it is silly. It is less important then the safety option mentioned above in this thread.