Daly bms issue 1st lower voltage and

[JPU]

Anyone encountered something like this?
Been trying to reset the app but still nothing happens. Or even factory reset.

Checked all my cells manually and they are perfectly balanced. All readings right now is 3.36volts. Only the first cell is 3.1v based on the app. And also the current reading in the app is -111.4A. but in actual there is no load. Nothing is going to be drawn from the batteries

 

[rickst29]

Pure SWAG, because I've never seen anything like that with my Daly units. (Wrong SOC? yes. Slightly wrong total voltage? yes. "Zero current" while low current is flowing? yes. But not these two isuues.)

The terminal lug which shares "B-", a bus bar, and the first (black) BMS sense wire is possibly suspect, but the wacky current reading implies something broken inside the unit. Did you ever try "starting it" via the Daly-banned method of shorting between B- and P- ?
- - - -
If this were mine, I would shut it down by pulling the BMS sense wire plug from the BMS unit. (IIUC, the BMS is powered by the Voltage on the sense wires, versus the B-). Then rest for 5 minutes, push the sense wires plug back in place. Next, I'd check resistance between B- and P-, just to verify that it did activate. (If high resistance and not activated, I'd use the SOC "light board" plug in - have you got one of those?)

 

[JPU]

Pure SWAG, because I've never seen anything like that with my Daly units. (Wrong SOC? yes. Slightly wrong total voltage? yes. "Zero current" while low current is flowing? yes. But not these two isuues.)

The terminal lug which shares "B-", a bus bar, and the first (black) BMS sense wire is possibly suspect, but the wacky current reading implies something broken inside the unit. Did you ever try "starting it" via the Daly-banned method of shorting between B- and P- ?
- - - -
If this were mine, I would shut it down by pulling the BMS sense wire plug from the BMS unit. (IIUC, the BMS is powered by the Voltage on the sense wires, versus the B-). Then rest for 5 minutes, push the sense wires plug back in place. Next, I'd check resistance between B- and P-, just to verify that it did activate. (If high resistance and not activated, I'd use the SOC "light board" plug in - have you got one of those?)

I already checked the resistance between the balance lead and they are perfectly fine. And yes i tried shorting B- and P- but nothing happened. My bms is working actually. Current passing through from my MPPT to my bms then to the battery.

But the readings in the APP is way of from the actual readings. All my cells are well top balanced

And nope unfortunately i dont have a SOC light board. Cant find any local supplier here.

 

[JPU]

Or maybe is it possible that my bms got busted by my MPPT?

My MPPT max output is 80A. But as of now i think my MPPT cant reach the max output because of my current PV setup. Maybe it can reach 50-60A.

Lets say my MPPT outputs 60A. But my BMS can only handle 50A of charge current.
Can this destroy my BMS?
Or the excess energy is just burned off as heat.

 

[rickst29]

The BMS may be disabled for excess charging, and that high current reading might be leftover from the shutoff event. It doesn't burn off energy, it uses an internal electronic switch to disable current in the charging direction. But I would guess that "charging" circuit to be only temporarily disabled, and not fried.

I'd re-program the MPPT parameters to set a maximum of 50A output, even though it is rated for more. (All the good ones are programmable, for that parameter.) Did you try the shutdown/restart via "removing the balance wire plug and waiting a while" method? You can also emulate the light board with a small resistor, although I'm not sure which pins are involved in the UART plug. "Search" would be your friend on that question.

I bought my "missing" lightboard from Daly (CN) on eBay, and it took only about 2 weeks to arrive. Packages that small are sent by air freight - not trapped at the port of Long Beach for weeks and months of waiting. But even though the current readings on my two currently installed Daly units are reasonably close, they don't handle low current "phantom loads" at all - and so the SOC readings can never be correctly derived via current * voltage readings. So I use a separate "coulomb counter" meter to assess what is really happening, for both SOC and actual current/voltage readings on the parallel battery pair. I only use the Daly readout to assess total voltage in storage (it's a travel trailer), and to confirm that the two BMS units are operational and responding on Bluetooth.

 

[JPU]

The BMS may be disabled for excess charging, and that high current reading might be leftover from the shutoff event. It doesn't burn off energy, it uses an internal electronic switch to disable current in the charging direction. But I would guess that "charging" circuit to be only temporarily disabled, and not fried.

I'd re-program the MPPT parameters to set a maximum of 50A output, even though it is rated for more. (All the good ones are programmable, for that parameter.) Did you try the shutdown/restart via "removing the balance wire plug and waiting a while" method? You can also emulate the light board with a small resistor, although I'm not sure which pins are involved in the UART plug. "Search" would be your friend on that question.

I bought my "missing" lightboard from Daly (CN) on eBay, and it took only about 2 weeks to arrive. Packages that small are sent by air freight - not trapped at the port of Long Beach for weeks and months of waiting. But even though the current readings on my two currently installed Daly units are reasonably close, they don't handle low current "phantom loads" at all - and so the SOC readings can never be correctly derived via current * voltage readings. So I use a separate "coulomb counter" meter to assess what is really happening, for both SOC and actual current/voltage readings on the parallel battery pair. I only use the Daly readout to assess total voltage in storage (it's a travel trailer), and to confirm that the two BMS units are operational and responding on Bluetooth.

I think I fried my BMS. Just checked my settings in the APP. The max charging current was set to 100A. But my BMS can only handle 50A. Maybe the BMS tried putting more current in and just fried itself.

Well, if ever this is why my BMS is not working properly, is all my fault haha
Should have checked all the parameters before powering up my charger on a sunny day.