Daly BMS Problem (150A/72V 20S)

jas67

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Oct 13, 2021
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I have a Daly 150A/20S BMS on my EV converted Vespa "VespaLectric".

The last time I tried to ride it, I switched on the main switch, tried to go, and lost all power.

Long story short, looking at the bluetooth app, it appears that the charge and discharge FETs are both shutting off like there is some sort of fault. I can get them to switch back on by opening and closing the main circuit breaker. After getting them back on, they turn off again within a second or two of trying to switch on the scooter, or when connecting the charger.

The pack is currently at 82.6V, which is about 85% SOC, and is well within the balance parameters. Is there anyway to read a fault history from these BMSs to figure out what the problem might be?
 
I have the same DALY problem with FET shutoff. I saw it happen when the temperature dropped below 8C, but when back in the garage at 16C the motorbike worked again. I'm still investigating why.
It is possible to connect a PC program called PC master, you can then read more parameters and update the firmware. I got this infor from other threads here.
 
Eskutr said:
I have the same DALY problem with FET shutoff. I saw it happen when the temperature dropped below 8C, but when back in the garage at 16C the motorbike worked again. I'm still investigating why.
It is possible to connect a PC program called PC master, you can then read more parameters and update the firmware. I got this infor from other threads here.

Thank you for this info. The BMS was reporting a temp of 6C when I had the problem.

I will warm it up and see if the problem "goes away".
 
Warming the battery pack inside seemed to "fix" the problem, but, this was only temporary.

Today, I revisited the problem, only to find a different problem with this BMS.

The voltage on the pack was WAY low, about 58V. Further investigation had the BMS reporting 0V for cell rows 15-20. I read the voltages directly from the balance leads with a DVM, they're all reporting normal voltages, about 4V (about 90% SOC).



I replaced the BMS, now all is as it should be.



This is the second failure of this model BMS that I've had in a little over a year, the first being the output FETs died on the first one that I had.

If I have another failure, I'm not going to want to spend another $135 for another DALY. What other smart BMSs are out there that might be better quality?
 
jas67 said:
I have a Daly 150A/20S BMS[/url] on my EV converted Vespa

Hi there, Only one question? Why do U still have a daly BMS? Do you want to burn your Vespa??
Does it even have low cut protection? did you tested by yourself?
Because some series of daly are kind of dumb protection mechanism (defect production)..maybe those millions of units need a recall :warn:

Some people talk good about Ants smart BMS's. I don't know..
Make your safe choice!
 
My choice of BMS is JBD with the blue elephant app.

I've tried about 3 different ant BMS in the last year and I hate all of them except the one model that doesn't require a 3.7v signal to turn it on.
 
jas67 said:
Warming the battery pack inside seemed to "fix" the problem, but, this was only temporary.

Today, I revisited the problem, only to find a different problem with this BMS.

The voltage on the pack was WAY low, about 58V. Further investigation had the BMS reporting 0V for cell rows 15-20. I read the voltages directly from the balance leads with a DVM, they're all reporting normal voltages, about 4V (about 90% SOC).



I replaced the BMS, now all is as it should be.



This is the second failure of this model BMS that I've had in a little over a year, the first being the output FETs died on the first one that I had.

If I have another failure, I'm not going to want to spend another $135 for another DALY. What other smart BMSs are out there that might be better quality?

I had same issue with my s13 Daly, one day just reported low voltage, works change voltage at random as I was trying to get home. At home i measured the pack and found that all was ok, replaced BMS and will not buy a Daly again. This was also a simple 30a variant, load from my bike was maxing out at 15a...
 
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