HateGrid
New Member
Nice solution sebdehne. As an optimisation, if you have the CAN or RS-485 Daly BMSs, you can configure each one with a different ID and use a single CAN-to-USB or RS485-to-USB converter to talk to all of them.
Daly Parallel Module
- Thread starter jontm
- Start date
Luxpower_Gilbert
Luxpert @Luxpower USA Team
my 2 pack have Daly smart bms, parallel module, and interface board (pylon Protocol) to work with my GSL 12k Hybrid inverter, sometime works sometimes don't, i think it work sometime because the GSL inverter use the newer Pylon protocol and the Daly interface board use the older one. it's nice when its working, I can control the both packs between 10%-90% charging/discharging.
HateGrid
New Member
Which interface board are you using?
Luxpower_Gilbert
Luxpert @Luxpower USA Team
Dalys interface board…
HateGrid
New Member
Ah, I wasn't aware they built that board! Thanks for that. Looks like Daly has finally stepped up their game. I had talked to them about 1.5 years ago about adding the Pylontech protocol to their batteries. I guess they got enough requests to finally add it!
Nice work! And as @HateGrid already mentioned, if you change the board number on your DALY BMS, you can address them separately using a single RS485 bus (or CAN, but I did not verify that). I have four 16S batteries in parallel reporting to one single RasPi on a RS485 bus. I had to flash the DALY BMS first though (check out my post in the resource section).
Regarding SoC: The DALY SoC numbers are virtually useless if you draw small currents. It seems there is no plausibility check with cell voltage. It seems to be a mere in/out-counter for current values and as known, DALY seems not to be able to detect anything below 0,3A (my experience with 100A-type BMS for 4S, 8S and 16S batteries). Hence I have batteries reporting 99.1% SoC but a cell voltage of 3.1V ...
So I will take your idea and extend my Python script with the surveillance of single cell voltages as I check right now only overall voltage. Thanks for the inspiration!
Xhumeka
Off-Grid'er
I finally had some time today to play around with a couple Daly parallel module packs I picked up (5amp version). From my testing (and the info I could find online) there is definitely more than just limiting current between packs, and it does seem to control balancing.
They do indeed seem to be communicating with each other - when I connected a discharged 25Ah 8s pack in parallel with an 80 percent charged 100Ah 8s the "system" immediately turned off the CHARGE mosfet on the 25Ah pack, and 5amps was being sent from the 100Ah pack to the 25Ah pack. Even though the 25Ah pack was completely discharged, when a charge current of 10 amps was applied the pack would not accept more than 5 amps. The BMS falsely reported the voltage to be much higher than it actually was, tricking the charger into thinking it was pretty much full.
Not sure if you've seen this video (it was only posted 2 months ago) but it kind of explains all the benefits of using their parallel module. At about the 1 minute mark it shows what I seemed to experience - the module balancing the two packs' voltage and a graphic shows the lower pack is somewhat disabled until the voltages balance out.
When I get more time later this week I'll continue testing by simulating typical use with a few discharge/charge cycles to see how well the parallel units keep the banks "in sync", and if I can see any difference when not using the parallel units at all.
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Xhumeka
Off-Grid'er
After a few more hours playing around with these parallel modules I'm not very impressed so far. I have yet to see much benefit of them in stationary solar applications other than amp limiting when packs are connected at different capacity levels.
In fact, they seem to introduce more problems than anything - one very odd issue I keep encountering is one of the BlueTooth modules quits showing up in my Android App after an hour or so of drain/charge. The rare time I have lost Bluetooth connectivity on another Daly 12v pack I built, but the easy fix for that is to just unplug the module for 5 seconds and reconnect it.
When this happens with the parallel units, a "hard reset" like this doesn't fix it. It's very strange behavior when this occurs - no matter how many hard resets I try, the unit continues to be greyed out in my app and inaccessible. If I unplug BOTH bluetooth modules, wait 10 seconds, then plug only ONE in (either one) it will show in the app right away. But plugging in the 2nd module does nothing, with the unit showing greyed out in the app.
So when this happens I'm able to connect to either pack individually (by going through the rig-a-ma-role above) but never to both packs, one always remains greyed out. The only way I've been able to have both show properly again is to have zero draw/charge on the affected bms (disconnect from battery bank basically), THEN unplug the module, wait a few seconds, plug back in. If these were in use and not just on my test bench, it would be inconvenient to have to do this.
My Android software is showing a firmware update available, but there's no way I'm going to do that based on other threads here! I'm going to run some more tests on these same BMS units without the parallel modules installed to help verify they are part of the problem.
In fact, they seem to introduce more problems than anything - one very odd issue I keep encountering is one of the BlueTooth modules quits showing up in my Android App after an hour or so of drain/charge. The rare time I have lost Bluetooth connectivity on another Daly 12v pack I built, but the easy fix for that is to just unplug the module for 5 seconds and reconnect it.
When this happens with the parallel units, a "hard reset" like this doesn't fix it. It's very strange behavior when this occurs - no matter how many hard resets I try, the unit continues to be greyed out in my app and inaccessible. If I unplug BOTH bluetooth modules, wait 10 seconds, then plug only ONE in (either one) it will show in the app right away. But plugging in the 2nd module does nothing, with the unit showing greyed out in the app.
So when this happens I'm able to connect to either pack individually (by going through the rig-a-ma-role above) but never to both packs, one always remains greyed out. The only way I've been able to have both show properly again is to have zero draw/charge on the affected bms (disconnect from battery bank basically), THEN unplug the module, wait a few seconds, plug back in. If these were in use and not just on my test bench, it would be inconvenient to have to do this.
My Android software is showing a firmware update available, but there's no way I'm going to do that based on other threads here! I'm going to run some more tests on these same BMS units without the parallel modules installed to help verify they are part of the problem.
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So it truly limits inrush current? I have a portable setup I'm building with 2x 280ah batteries and 5A parallel modules and I have been reluctant to parallel them at different SOC. I was in the process of building an external current limiting circuit with a 0.1 ohm resistor betwen the positive poles. With your results, I will try to parallel them at "very near" SOC to see if they balance at 5A only.
This functionality is very important to me as each battery would be usable as standalone units, that would be paralled when I need bigger capacity or when charging. I don't want to deal with inrush current each time I parallel them and I want this to be "dummy proof" also!
What is the highest difference in SOC you have tested?
I Will also check the bluetooth connectivity to see if I get the same results.
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Luxpower_Gilbert
Luxpert @Luxpower USA Team
Here’s my set up with daly interface board and parallel module..
https://diysolarforum.com/threads/d...-energy-via-interface-board.49636/post-677536
https://diysolarforum.com/threads/d...-energy-via-interface-board.49636/post-677536
Xhumeka
Off-Grid'er
The bluetooth issue seems hit-or-miss... it happened to me a few times the first couple of cycles, but the last couple of days the issue hasn't resurfaced.
From my testing if you parallel batteries with similar SOC, there would be no balancing at 5A - the balancing only happens (and the lower BMS' charging is disabled) when there is a large discrepancy. As for the highest difference in SOC I have tested, likely 90% vs 10%.
Here's a video from Daly demonstrating the inrush current limiting:
How has it been working over these past months? Has there been any stability issues? I'm considering a similar setup.
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