Cheap Chinese junk: I'll trow my 3 Daly controllers in the garbage bin. ANGRY!!!

rudydevolder

Solar Enthusiast
Hi to you all, I'm decided, I'll trow all my Daly BMS-es in the garbage bin. 😡
I started to hate them after I broke 2 of them because I disconnected them in the wrong way to test and swap to the other again, I should have known better to disconnect the “-“ to the battery as last, but I was already tired and fed up with the extremely bad translated incomplete manuals, the mistakes they made in my order, wrong documentation about the connections and not standardizing their own connectors for UART and CAN-Bus between their different models. I opened up 1 Daly BMS to look what’s under the hood, looks very nice at the outside, inside the electronics are terrible oversimple. I didn't noticed at first they only balance 30mA. I had too much trust in them because Will Prowse really advised them as good quality. In my application I think 30mA is really way too low. And actually selling a 400 Amp BMS that does only a balancing current of 30mA sounds a bit silly, no?
  1. The higher the main-current the higher the balancing current should be. It seems ALL their BMS's are 30mA balancing current only. Ranging from their 20 amp models to 400 Amps, ridiculous. Sometimes I draw 200 Amps for several minutes for my cable-cart motors, I didn't test yet on my batteries but after a few trips, I'm sure I'll need more balancing current than this, maybe not with brand new batteries, but I think when 1 or 2 year old my system will start to show failure and resetting the Daly BMS after an error seems to be a manual job; ARGHHH! I don't want to think about.
  2. Using a MOSFET as safety breaker is STUPID! It should be a relay that is normal open. The reason is simple: when the system fails because of a current being too high, like a high inrush-current or shortage, the MOSFET will fail as first! And the way a MOSFET tends to fail is to make a short, ALWAYS! You can't disconnect any-more! The Dali has no inrush-current protection what-so-ever! What safety-rating you give this? A relay tends to fail open, I know there is a very slight chance it fails closed because of contacts being welded from high current, but if your relays are strong and big enough, this should NEVER happen.
  3. A inrush-current protection is not only necessary for the BMS itself, it's also important for the devices connected as a load. Like a BLDC motor controller has big capacitors inside, also DC/AC inverters have big capacitors, at startup their resistance is ZERO for a short period, just like a short-circuit! You can blow them up from the first moment you connect them destroying your Dali AND your inverter in one go!!! If not in one go, it will happen the next time when you switch down the whole system, replace a battery and turn it back on, or the next time it happens. So, you must have a pre-charge circuit first like a extra relay with an in series resistor that limits the current for a few seconds to slowly charge up the capacitors in the load and only than go to full power.
  4. I bought the newest models with bluetooth, UART and RS-485, on all 3 models of my Daly-controllers the connection scheme is different. WTF!!! They can't respect their own standards! Only after opening one I found out that the naming of the pins was printed on the PCB. But their docs were wrong or insufficient!!! ARGHHH!!!
  5. After opening I can't find any TVS diodes or any other protection, the system is utterly simple. No TVS-diodes even with a CAN-bus and RS-485!!! This is asking for trouble sooner or later. When in an environment with large currents you get VOLTAGE DROP and EMI ( ElectroMagnetic Interference ), always. This results in very short but high interference peak voltages in your communication cables. TVS-diodes are very fast reacting diodes that short out these Voltages the moment they go above the small 3v3 that your microprocessor is working. In the Daly I saw no TVS and also no buffering at first glance. Very poor design.
  6. Also measuring the Voltage over the same cables you do send the balancing-current seems not a good idea to me. You always get a voltage difference that's why they recommend not using any other cables and not to make them different lenghts, because you'll get wrong voltage readings because of Voltage drop. It would better to different cable for sensing but if the differences cancel each other out I would say OK.
I communicated with Joyce from Daly, she is always very kind and polite and calls me always dear. She invited me to send the boards to them. But she could not assure it's warranty. I said them, of course it's no warranty, I disconnected them in the wrong order, but they should WARN in their manual also. So, yes it should be warranty because their manual is bad. I said please I am prepared to pay only for your cheap replacement spare board and I will do the repair myself. Lightweight package also just 2 small PCB boards. So, cheap transportation. No, she don't want, she want still to figure out what happened while I explained already how easily I blew it up!
I had a ARGHH moment again!!!
That was my moment I decided, NO WAY!!! Go to hell! I didn't said it that way, but that was my feeling, I think you understand.
At 2 o'clock after midnight I was thinking it's better to design my own BMS. I don't like expensive systems that are like a black box and you don't know whats inside. So I started searching for a good Chip from TI or so that is specialized in BMS and also some open source BMS's. Bad for my high blood but I couldn't sleep before I found something interesting enough so I started searching and browsing the internet.

To be continued....
 
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Steve_S

Offgrid Cabineer, N.E. Ontario, Canada
I appreciate your frustration and the resulting angst but I have to point something out about these & other BMS'. There are TWO types of Balancing, Passive & Active, the Daly you have, like the majority of small BMS', use Passive Balancing, not Active. This means they will simply burn off voltage from high volt cells, that's it, that's all. Active will transfer voltages between cells and is a much more involved process. You can expect to pay $150 USD+ for an 8S active balancer and hey can get really pricey.

Making your own BMS is quite a thing to get into... Many options to ponder which are best left to when your Bright Eyed & Bushy Tailed with a fresh mugga in hand.
 

rudydevolder

Solar Enthusiast
I appreciate your frustration and the resulting angst but I have to point something out about these & other BMS'. There are TWO types of Balancing, Passive & Active, the Daly you have, like the majority of small BMS', use Passive Balancing, not Active. This means they will simply burn off voltage from high volt cells, that's it, that's all. Active will transfer voltages between cells and is a much more involved process. You can expect to pay $150 USD+ for an 8S active balancer and hey can get really pricey.

Making your own BMS is quite a thing to get into... Many options to ponder which are best left to when your Bright Eyed & Bushy Tailed with a fresh mugga in hand.
Hi Steve, I did some research in the mean time and read many reports from real specialists like engineers from BMW, cheap active BMSes are no good option either. It's better to have a good passive BMS than a the cheap Chinese based on capacitors only. I forgot what it was but these are not good either and can fail easily when the out of balance current gets higher than what they are designed for, they have no current limiter built in for the balancing current, as the voltage difference get's higher and the balancer can't get up the balancing current get's higher and when the limit is reached POOF! I've read clearly in the comments that it happened multiple times with someone.
I said to be continued, I promise it will be very interesting and the solution I found is a very interesting open source project from a CANADIAN electronic engineer that based his work on a German hobbyist using a LTC6811 chip from Analog Devices as a charge controller for his electric skateboard that can do 80 km/hour, so wait until tomorrow because I need to go out now. BYE BYE
 
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rudydevolder

Solar Enthusiast
Like I said I've found a very interesting information and a specialized chip the LTC68xx series. Each chip can handle max 12, 15 or 18 channels or battery-cells with a accuracy of 1.5mV. And it has a isoSPI bus to connect multiple chips in series, completely galvanic isolated at 1mbps over max. 100m using 2 wires only. The chip costs around 20 USD and the manufacturer sells a development kit with a master and slave board, and multiple slave boards can put in series. The master board has usb connection and free software 100% compatible with the Arduino with the same pin-layout. But they call their own master board the Linduino, their demo slave boards do already balancing of 50mA, compare this with the Daly that has only 30mA. I was very interested in this one, but than I tried to figure out the datasheet of the chip, I had a headscratching moment, wow a 92 pages datasheet with explanation of filters and many other features like cross-checking. This is not going to be a easy task. But it made me convinced in the capabilities and reliability of this chip, so I started looking for open-source projects with source code to look at.
Hurray, I found the DieBie BMS from a German engineer and a die-hard electric skateboarder. I admired his project but it was not exactly the thing I was looking for, first because it uses the older LTC6803 chip, second it had no extensions for more batterie-cells and 3th it was really leaning more towards electrical vehicles than energy storage. The next open-source project I found was actually based on this one. It is the ENNOID BMS, this project is using the newer version the LTC6811 and Stm32 microcontroller on a separate master board and what I really like is the modular configuration with slave boards you can put in series, the balancing current is 110mA and I was ready to make a very simple adaptation to make it higher but Kevin(the engineer of the ENNOID BMS) said I could buy his older boards with 220mA balancing current. He has multiple models of his slave board and all schematics and source code is available online, both the sourcecode for the master board based on the Diebie bms firmware and the graphical interface on windows which is very straightforward to use. Love it. The only thing is that his current implementation is more towards electric vehicles. But Kevin said no problem together we can do the small adaptations in the software and implement in the next version. The accuracy of the LTC68xx is 1.5 milli Volts, so balancing while charging even halfway should be no problem I think.
To be continued...
 
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Dhopewell

Solar Enthusiast
I’m sorry to hear of your experience - my “smart” bms is arriving next week. It sounds like you were referring to the Electrodacus bms. I want to live a simple life wrt my battery but a FET free bms sounds better. At one time I understood quite a lot about high voltage AC, and am puzzled why it’s so hard to solve a low voltage DC problem like this. The currents can get high, but I think maybe it’s that battery builders are forced to use scaled up scooter parts that were designed for intermittent loads.
 
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rudydevolder

Solar Enthusiast
I’m sorry to hear of your experience - my “smart” bms is arriving next week. It sounds like you were referring to the Electrodacus bms. I want to live a simple life wrt my battery but a FET free bms sounds better. At one time I understood quite a lot about high voltage AC, and am puzzled why it’s so hard to solve a low voltage DC problem like this. The currents can get high, but I think maybe it’s that battery builders are forced to use scaled up scooter parts that were designed for intermittent loads.
The Electrodacus looks a nice system but has only Mac. 8 cells in series. With the ENNOID BMS you can put theoretically as many in series as you want. ENNOID has the choice in 2 different MASTERS. One can go as from 30v high as 150v 500 amps continous! This is the Low Voltage model!!! The high voltage model
works between 100v and 400v, 500 Amps continuously! And they work with the same slave modules.
Love this system.
 

rudydevolder

Solar Enthusiast
The Electrodacus looks a nice system but has only Max. 8 cells in series. With the ENNOID BMS you can put theoretically as many in series as you want. ENNOID has the choice in 2 different MASTERS. One can go as from 30v high as 150v 500 amps continous! This is the Low Voltage model!!! The high voltage model
works between 100v and 400v, 500 Amps continuously! And they work with the same slave modules.
Love this system: https://www.ennoid.me/battery/bms
 
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rudydevolder

Solar Enthusiast
Many don't know but on the market there's 90% of LED lights for the house that actually have a forward voltage between 35 and 45 volts. I bought some dimmable led lights everywhere on Aliexpress and tested this myself. So perfectly suitable to drive with 48v.The driver is to lower the voltage and give a constant current. I bought already many LED ceiling lights throw away the 220v driver and using a high quality Led driver from Meanwell that can be remotely controlled and dim the lights. No need to transform the voltage so much more energy efficient. Also many dc motors like pumps on this voltage. 48v you can still touch without being electrocuted being considered a safe limit.
 

Supervstech

Administrator
Staff member
Moderator
Many don't know but on the market there's 90% of LED lights for the house that actually have a forward voltage between 35 and 45 volts. I bought some dimmable led lights everywhere on Aliexpress and tested this myself. So perfectly suitable to drive with 48v.The driver is to lower the voltage and give a constant current. I bought already many LED ceiling lights throw away the 220v driver and using a high quality Led driver from Meanwell that can be remotely controlled and dim the lights. No need to transform the voltage so much more energy efficient. Also many dc motors like pumps on this voltage. 48v you can still touch without being electrocuted being considered a safe limit.

I disagree with you on the 48v being considered a save to touch voltage...

I do not recommend testing this...
 

rudydevolder

Solar Enthusiast
I disagree with you on the 48v being considered a save to touch voltage...

I do not recommend testing this...
 

JoeHam

Photon Sorcerer
Many don't know but on the market there's 90% of LED lights for the house that actually have a forward voltage between 35 and 45 volts. I bought some dimmable led lights everywhere on Aliexpress and tested this myself. So perfectly suitable to drive with 48v.The driver is to lower the voltage and give a constant current. I bought already many LED ceiling lights throw away the 220v driver and using a high quality Led driver from Meanwell that can be remotely controlled and dim the lights. No need to transform the voltage so much more energy efficient. Also many dc motors like pumps on this voltage. 48v you can still touch without being electrocuted being considered a safe limit.

Do you have a link to some 48v LED lights?
 

Supervstech

Administrator
Staff member
Moderator
That is a nice set of answers regarding Poe shock hazards to ground... completely different from 48v battery terminal to terminal...

Trust me... 48v can and will kill you. It is very easy to prevent electrocution from it, as it isn’t grounded, and if you only handle one conductor at a time, a shock is unlikely... but 48v is well above the 28v, skin voltage shock threshold...
 

juanmijm

Solar Enthusiast
What happened to this thread, I just discovered it and it seems very interesting to me, because I bought a daly bms and it makes me want to throw it off the balcony, it's bad bad, meaningless ports, I don't know if it's on or not, app bad, disgusting.
 

Just John

Photon Sorcerer
I can tell you for a fact that anything over 30 volts is dangerous. Dispute with "internet experts" quotes at your own risk. My knowledge might date to the 1970s and earlier, but it hasn't changed.
 

JoeHam

Photon Sorcerer
And 120v ac is dangerous also.

I have built and use different 48v systems in my home, barn and boat house without issue.

I respect the 48v dc input and the 120/240 v ac I get out from the various inverters and have no issues.
 

Supervstech

Administrator
Staff member
Moderator
And 120v ac is dangerous also.

I have built and use different 48v systems in my home, barn and boat house without issue.

I respect the 48v dc input and the 120/240 v ac I get out from the various inverters and have no issues.
Nobody is saying the voltage cannot be manipulated safely.

we are all saying that the voltage can be very deadly unprotected, and handled as if it is a car battery.

48v, or even 24V can kill.

the conditions need to be nigh ridiculous, but, in warm conditions, or around children, the wrong step could be the last one made...
 
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