I've read many posts about it, yet I can't get mine right. Have an easy solar connected to a power in (fused) connected to a smart shunt and 2p4s 12v 190ah batteries.
I've set up the total ah (760) in settings and discharge floor of 50% being agm.
I'm down at 24.4V (50%) atm ready to run the generator and the percentage shown is at 95.4 lol.
I'm not expecting extreme precision but it's way off isn't it.
How can I correct it?
Thank you
Do you mind sharing the battery chemistry you have an also your current smart shunt settings. That should be enough for the community to recommend correct settings that should help.
Here the shunt settings, batteries are supersafe 190f AGM.
Thank you
Are you sure you have 760 Ah Battery Capacity with a 2P4S configuration?
Maybe you have a 2S4P configuration?
That would be 720 Ah.
Are you sure all of your loads are connected through the SHUNT?
Nothing connects to the Bat (-) except the shunt?
Charged Voltage = 13.5v ( = 27.0 v / 2 )
Do you charge your batteries to a voltage higher than 13.5 Volts?
How old is the battery bank?
2s4p indeed.
All loads pass via shunt, no extra chargers either.
Battery bank --> power in --> shunt in correct direction on negative --> breaker --> easysolar.
I charge them as datasheet specs absorption 28.8v and float at 27.24v.
They about 5 years old .
Cheers
Do you have any statistics for Amp-Hours Charged vs Amp-Hours Discharged, for the last cycle?
Could the capacity of your battery bank be severely degraded?
So, your Absorb voltage = 28.8v, but you set SOC = 100%, early at 27.0v during Bulk?
Is that correct?
Did this ever work accurately?
Did your load actually pull 380Ah ( 50% ) from the battery bank?
I want to verify the Voltage dropped due to consumption.
Is the Battery Bank fully (100% SOC) recharged every day, held @ 28.8v Absorb for hours?
Are the two batteries, connected in series of equal voltage?
Here some screenshots of last 24hr, hope they help.
Lowest point is because a milk frother, just for few seconds.
I'm thinking they have some degradation but nothing too bad, somewhere between 90-85% capacity I reckon but that is a rough estimation. Definitely not dead and performing well when charged.
You are correct about the absorb at 28.8v on the mttp settings while the charged voltage on shunt set .3 below float voltage on mppt as victron instructional video.
Never worked accurately in 6 months but was a bit better at the beginning (guess it will keep changing).
Not sure I understand the question about pulling 380Ah but in a day like yesterday where I'm home all day and there's not much sun I definitely hit the generator by late arvo.
I'm sure now in winter the battery doesn't get fully charged as we don't have enough sun, gone on panels by 2/3pm. Generator does a rough charge about an hour a night to make sure everything is fine in the morning but never let it go for longer.
I don't have an equalizer between batteries but I'm sure they close enough, I did a test before fitting after they been sitting for few days with no load but can't be sure.
Thanks for your time, I'm in a funny space where I understand most but lacking some basic knowledge as well so is really appreciated having someone keen to go in dept.
Ps: I live in a stationary motorhome, loads are:
- few lights
- 70w small fridge
- 2 laptops (one I game on every night for few hours and uses some juice)
- chargers
- 2 modems
- milk frother (500w few minutes a day)
- occasional vacuum 900w
Apart the spikes, we usually stay around the 150-250w usage constant when we home in the evening
Won't allow me to update pictures, tried different platforms I think is a problem with the forum.
https://ibb.co/Y2p7RjF
https://ibb.co/7g18Bqr
https://ibb.co/kGbY0Sy
You shunt settings will cause it to synch to 100% with a charge current below 30.4A for 3 minutes.
Your charge rate never goes over 30A. So the shunt synchs falsely.
I don't see any evidence of the generator kicking in.
Firstly reduce the tail current setting to 2% or lower. And increase the charge detection time to about 10 minutes. Increase charged voltage to just below absorption, say 28.7V. You're going to have to experiment a bit here. Individual installations need individual tuning. But the key is to stop the false synch. More on this later.
Secondly check that all charging sources go through the shunt load side.
Thirdly, get a full charge in the batteries by running the generator for longer. Its charger must go through absorption into float.
On the shunt settings, yours are set to default for charge detection. Nothing wrong with that, but solar charging needs changes - lower tail current and longer detection, due to cloud/low sun levels. This is at odds with generator needs, which are defaults... To make things worse, your solar is inadequate, leading to charge currents that are low for the battery size. Preventing the false synch to 100% on solar may lead to poor or zero synch with generator. If you can't find shunt settings that work for both, probably best to run the generator until its charger kicks into float.
Screenshot_20230721_142400_VRM.jpg
Done, thank you.
It is inadequate for this time of the year I know, it's just these 2 months of deep winter here in TAS. Never had problems with longer days even with other systems I had before.
You can see the generator kicking in the graph, as said we usually not home during the day but we been both sick si we use power all day long, this is not the standard.
I'll experiment between time and tail I guess it's your suggestion yes?
Thanks for your time.
Gab
