Another DALY Quirk-Issue

SolarKimmy

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Joined
Dec 3, 2019
Messages
189
I have a strange issue that perhaps the mental collective of this forum can shed some light on:
My 12V Nominal system consists of six banks of 280AH packs in parallel to a common bus. Each pack has a DALY 4S Smart BMS. The BMSs are all wired correctly. I have verified this.
Now, 4 of the packs have a DALY 80Amp Smart BMS. 2 of the packs have a DALY 120Amp Smart BMS. The firmware numbers are:
80A--210103
120A--20210512-303IT
When charging or discharging and reading the 80A, everything looks ok, except the SOC is never accurate.
Here is one of the 80A with large load (microwave running) and it's showing a discharge. Negative number.
IMG_9104.PNG
Now with the same load running, the 120Amp BMS never shows a negative number, although it's pulling from the pack. It's showing a positive draw (or absolute value) from the pack. Relatively the same amp draw on this test.
IMG_9103.PNG
Can anyone figure out why the 120A BMS (both of them do the exact same thing) only shows a positive number on charges and discharges? The 80A BMS s (4 of them) all perform the same and show positive charges and negative numbers on discharges.

Another note, The packs have been in service for 8 months. The BMS maintains balance very well, less than .008 Delta on all the packs. It's usually more like .003. I have never seen the balance come on/activate, so I'm not sure if it does anything or the batteries are just great cells. Perhaps, they just naturally level out overnight. An opinion this would also be appreciated.
 

SolarKimmy

Solar Addict
Joined
Dec 3, 2019
Messages
189
I have a strange issue that perhaps the mental collective of this forum can shed some light on:
My 12V Nominal system consists of six banks of 280AH packs in parallel to a common bus. Each pack has a DALY 4S Smart BMS. The BMSs are all wired correctly. I have verified this.
Now, 4 of the packs have a DALY 80Amp Smart BMS. 2 of the packs have a DALY 120Amp Smart BMS. The firmware numbers are:
80A--210103
120A--20210512-303IT
When charging or discharging and reading the 80A, everything looks ok, except the SOC is never accurate.
Here is one of the 80A with large load (microwave running) and it's showing a discharge. Negative number.
View attachment 68752
Now with the same load running, the 120Amp BMS never shows a negative number, although it's pulling from the pack. It's showing a positive draw (or absolute value) from the pack. Relatively the same amp draw on this test.
View attachment 68753
Can anyone figure out why the 120A BMS (both of them do the exact same thing) only shows a positive number on charges and discharges? The 80A BMS s (4 of them) all perform the same and show positive charges and negative numbers on discharges.

Another note, The packs have been in service for 8 months. The BMS maintains balance very well, less than .008 Delta on all the packs. It's usually more like .003. I have never seen the balance come on/activate, so I'm not sure if it does anything or the batteries are just great cells. Perhaps, they just naturally level out overnight. An opinion this would also be appreciated.
I heard back from DALY. It's defective in their software. They said "sold before 7/32/2021 charge is negative and discharge is positive". That is what is going on. So much for their crack engineering department. I'm still waiting on an answer if a firmware update would fix it.

I also mentioned that I have 6 battery packs in parallel. He said I must use a "Parallel Module" for this. I have never heard of this product and it is nowhere to be found on the DALY site. He provided this diagram and pic of the parallel module. Has anyone heard of this?
parallelmodule.jpg
 
Last edited:

Sharky722

Solar Enthusiast
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May 8, 2020
Messages
148
In the sinowealth sw what does the 'cadc gain' setting say? Should be a negative number.
 

crossy

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Joined
Apr 27, 2021
Messages
84
I have the same issue, got 3 x 100A Smart BMS's, two read -ve on charge one reads +ve.

I'm tempted to do something ESP8266 ish to sit in the comms to flip the current value on one of them, unless someone else has done it already of course.

I also run all in parallel, it seems to just work, no "parallel module" whatever that is.
 

SolarKimmy

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Joined
Dec 3, 2019
Messages
189
I have the same issue, got 3 x 100A Smart BMS's, two read -ve on charge one reads +ve.

I'm tempted to do something ESP8266 ish to sit in the comms to flip the current value on one of them, unless someone else has done it already of course.

I also run all in parallel, it seems to just work, no "parallel module" whatever that is.
The idiot I was texting to in China refused to tell me anything about the parallel module. He just says "You need if in parallel", and it's $65.00 Each. My six battery packs run fine without it plus he will absolutely not tell me what it does, electrically. I personally think he is a candidate for the Chinese version of a short bus.
 

SolarKimmy

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Joined
Dec 3, 2019
Messages
189
The idiot I was texting to in China refused to tell me anything about the parallel module. He just says "You need if in parallel", and it's $65.00 Each. My six battery packs run fine without it plus he will absolutely not tell me what it does, electrically. I personally think he is a candidate for the Chinese version of a short bus.
Ok, I got some official word back from this brilliant technical expert in China. He stated :

"Parallel system is to solve the problem that high-voltage battery pack charging to low-voltage battery pack due to the voltage difference between the battery packs. Because the internal resistance of the battery cell is very low, so the charging current is very high, which is prone to danger."


Now, my six packs are on a parallel bus. So, they just naturally balance overnight when not charging. When charging, the current is nearly equally divided between all six battery packs within one or two amps. So I really do not see a need for this device and Plus, the person I was communicating with (joke) cannot tell me what it does, electrically.
 

crossy

Solar Enthusiast
Joined
Apr 27, 2021
Messages
84
@SolarKimmy so in reality it is supposed to provide protection if we try to parallel a full pack and an empty pack.

With a little care and common sense we don't do that.

I do sometimes see my packs swapping charge (one charging from the other) but at currents around an amp or two, I suspect that happens when the 4A active balancer is operating.
 

SolarKimmy

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Joined
Dec 3, 2019
Messages
189
@SolarKimmy so in reality it is supposed to provide protection if we try to parallel a full pack and an empty pack.

With a little care and common sense we don't do that.

I do sometimes see my packs swapping charge (one charging from the other) but at currents around an amp or two, I suspect that happens when the 4A active balancer is operating.
I think we are both accurate here. care and common sense goes a long way, but not as far as China.
 

nwillitts

Solar Addict
Joined
Dec 29, 2019
Messages
547
i have the same charge/discharge issue,everything is in reverse,and it is hooked in parallel with another pack.works fine otherwise.
 

Maniac54

New Member
Joined
Jun 23, 2021
Messages
5
Location
Athens, Greece
I have also the same charge and discharge problem. I use 2 smart bms models R25A-GH02 and R16A-FL02. After communication through seller I was informed that software update is not possible.
 
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