MPPT 150/50 CUTTING OUT AT 98% charge?

DIY
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1

Hi,
I’ve got a victron MPPT 150/50, with around 1000w of 24v PV connected to Victron Inverter 24v 2000w/4000w peak.
This is connected to 200ah 24v battery, AGM.
It’s all new. Only 2 months old.
I have a Victron SmartShunt also connected the battery bank.

It’s all been functioning perfectly for the past 2 months, staying on Float on sunny days for majority of the day, recharging well after few cloudy days back to Float, adjusting power output when under load etc.

Now it seems that the charge controller cuts the power to batteries once they are around 98% charged (4ah used, according to the smartshunt).
So it stays in absorption for only about 30-40 minutes before dropping the power to 0W. It then stays fluctuating slightly to 1W or 2W occasionally, but mostly 0W
If I use my electric For 20 minutes, or 4ah or so, it then kicks back in and charges back to around 98% then cuts the power again. This goes round each day the same.
The PV is fine, always showing good charge Voltage of around 39V. When it works, it shows the full 1000w of power is getting through.
Batteries show a good resting Voltage 25.2V.

I have the battery charge settings on the MPPT as follows:
Abs V - 28.8V
Float V - 27.6V
Tail - 2ah (1%)
ABSORBTION TIME - adaptive

SmartShunt settings
Charged Voltage 28.6v

I’ve also tried resetting the MPPT BY REMOVING ALL the connections and leaving it off for at least 20 minutes before reconnecting… many times… doesn’t seem to change

Help!!?? Anyone😕

Thank you in advance!

3

What ate your other settings on the shunt, especially the tail current and the charged detection time. Take a screenshot and post them here.

It the controller getting to the absorption voltage and staying there for 2 hours or until the current is less than 2A. It is probably your shunt set wrong rather than the solar not working.

4

I’d set it to 2 hours

5

Thanks for your input…. Here’s a screenshot

IMG_0695
IMG_0695734×1405 161 KB

Any thoughts ?

Thanks!

6

And here are my MPPT charge controller settings…

IMG_0696
IMG_0696708×2048 213 KB

7

Well that SmartShunt will never set to 100% when the battery is full, the tail current in the SmartShunt has to be HIGHER than the MPPT setting as it has to go below this value to reset. Change the tail current in the SmartShunt to 1.5% or 2.0%. Also for AGM reduce Peukert to 1.15.

Read this FAQ for info on how the shunt works to set to 100%.

Shunt setings