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Daly BMS switching off

Kerry downunder

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Sep 28, 2020
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I have a 24V 240ah battery with a Daly 150A BMS connected to a 3KVA 3000W Solar Inverter Charger Hybrid 24V MPPT 80A Controller High PV 500Vdc. I have 8 X 350 watt solar panels connected in series as the inverter requires 106V from the PV to work.
When switched on the system works well for anywhere from 5 to 20 mins and than the inverter switches to the shore power. The battery is still at close to full charge when this switch happens. I have also tested the system with the shore power switch off and this still happens. I have measured the voltage from the battery after the shut down and it is 17.5 V after the BMS however it is 26.9V before the BMS. I have checked all my settings on the BMS and I cannot work out what is happening. Any suggestions?
Do I have to replace the BMS?
 
can you try to re-explain this?
Ok, the set up is a 24V 240ah battery pack with a Daly 150amp Smart BMS, a Hybrid Inverter 3K that is also connected to shore power, 8 solar panels each 350 watts connected in series.

when I switch on the inverter, it powers up from the solar and battery supplying 230V. after a time frame of 5 to 20 minutes the inverter switched across to shore power for no apparent reason as the PV is still at above 106 V and the battery is still at 90% charge according to the app connected via bluetooth to the BMS, however, on measuring the output of the battery after the BMS it only reads 17.5V, but before the BMS it reads 26.9V.
The screen on the inverter shows no battery power.
I tested the system with the shore power disconnected and the system ran for 20 minutes before switching off.

It appears to me that the BMS is switching off the output of the battery, and I do not know how to rectify this action of the BMS.
 
Guessing problem with bluetooth (BMS okay); is BMS software latest & greatest?
 
I did not see the device you linked, but I think it is some sort of all in one.

What has caused my smaller DALY BMS to trip is exceeding the charging amperage, but I am still able to discharge from it, just not charge.

What you have your cutoffs for on the BMS would help also. A Low Voltage cutoff set a little too high would shut off battery dischage, especially if some surge load came on like an Air Conditioning or microwave.
 
This is the Inverter screen. These were taken within 5 min of each. It shows the inverter running from the battery and PV, then the the battery is switched off somehow.
The BMS is set at 22.5V for cutoff and 2.8V for each cell.
 

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I did not see the device you linked, but I think it is some sort of all in one.

What has caused my smaller DALY BMS to trip is exceeding the charging amperage, but I am still able to discharge from it, just not charge.

What you have your cutoffs for on the BMS would help also. A Low Voltage cutoff set a little too high would shut off battery dischage, especially if some surge load came on like an Air Conditioning or microwave.
The charge is 75A and the discharge is 150A. The battery has not gone below 80% SOC.
 
I'm having a similar issue with my Daly 48V 16S 150A (model R32U1, I guess). It'll be happily charging/discharging for a few minutes/hours and then randomly disconnects from the inverter. It looks fine if it wake it up again - no faults displayed or anything - but then it just disconnects/falls asleep again after not too long.

With this, I've supposedly disabled sleep, by setting the timer to 65535, but it will still randomly disconnect/sleep...

I've run across another post claiming that a firmware update helped them, but so far Daly is telling me my firmware is current.
 
I'm having a similar issue with my Daly 48V 16S 150A (model R32U1, I guess). It'll be happily charging/discharging for a few minutes/hours and then randomly disconnects from the inverter. It looks fine if it wake it up again - no faults displayed or anything - but then it just disconnects/falls asleep again after not too long.

With this, I've supposedly disabled sleep, by setting the timer to 65535, but it will still randomly disconnect/sleep...

I've run across another post claiming that a firmware update helped them, but so far Daly is telling me my firmware is current.
I tried to disable the sleep setting to no avail. Every time the battery connects, it charges and once it reaches full charge( which is only within 2 to 5 minutes, it switches off again.
 
I think I figured out what was going wrong with me. I had a balance lead that was connected just well enough that everything would look fine just sitting there--but once the inverter started charging/discharging, the connection would break down and look like the cell was going too low, and trigger the BMS protection cut-off.

With that, I totally don't get why the BMS would shutdown and become inaccessible over bluetooth, just because the protections had triggered - but apparently, it's acting "normally" otherwise ?
 
With that, now my cells are too far out of balance 'cause that one wasn't getting charged/discharged correctly, so now it's back to top balancing the whole pack... ?
 
I did not see the device you linked, but I think it is some sort of all in one.

What has caused my smaller DALY BMS to trip is exceeding the charging amperage, but I am still able to discharge from it, just not charge.

What you have your cutoffs for on the BMS would help also. A Low Voltage cutoff set a little too high would shut off battery dischage, especially if some surge load came on like an Air Conditioning or microwave.
So am about building a an 8s bank with daly 120amps/60amps BMS. Now the inverter is set to charge at 45amps, while the charge controller is hooked to 4 x 350w solar panels. Which on a good sunny day brings in over 40amps charging current.

So if this combined amperage of 85amps hits the BMS, what would happen?.

Would it trip off and shutdown, or it would disconnect the charge FETs?. Or catch fire ? and burn.
 
So am about building a an 8s bank with daly 120amps/60amps BMS. Now the inverter is set to charge at 45amps, while the charge controller is hooked to 4 x 350w solar panels. Which on a good sunny day brings in over 40amps charging current.

So if this combined amperage of 85amps hits the BMS, what would happen?.

Would it trip off and shutdown, or it would disconnect the charge FETs?. Or catch fire ? and burn.
In my case with the Daly 15 amp BMS an overamperage on the charge side shuts down the charge only but can still discharge from the battery.
 
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