DALY BMS Teardown & Failure Review (16S 40A)

Android Messaging HiJack

I just had to fix one of these. This is the case where you go to text someone and it says they are offline and prompts you to use SMSMMS.

Here is the TL:DR

* SMS or MMS is old school over the towers (where SMS is text and adding images pushes you into MMS)
* RCS is a turd
* People were getting mixed up with conversations on two different "messaging" platforms, so they smooshed them into one
* I turn OFF RCS and maintain backward compatibility with SMS/MMS
* Open the app, go to settings, go to chat, turn it off

This will get rid of all that crap where you try to text someone and it says they are offline and prompts you to switch to SMS/MMS. For me, mine ALWAYS says I am offline because I never verified my phone number wiht any RCS services.

* Texting != Chatting

Chatting is something you do on Facebook or equ. Texting is something you do over cell towers.


Here are the first two failed units. Both of them still display the disruptive and dangerous feature of not blocking a discharge.


Here we have the 10AWG left over from the battery


My rule for wago goes like this

* Copper showing past the spring
* Copper showing before the spring
* Insulator inside
* Pull test


I've got these things running everywhere...

* 120Vac
* 240Vac
* 420VDC....

* Indoor
* Outdoor

On the golf carts they do corrode out if abused



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Still not compressing
Oh well, now my thread is fouled with a 5MB picture. WHATEVAR.

* That is 10AWG Silly
* Not all silly works if insulator too thick
* Works for solid tho not as well IMHO

Pull Test holds far better than a PP45, BUT STILL LETS GO IF YOU NEED IT TO

Here is one fresh out of the box in perfect working order. I will quickly video what it should look like. I don't have my tripod


Noticed that I name it QC003
In a subtle color, just in case it passes*


* Before we do incoming inspection

Today we have an empty pack so we are going to start with 20 amp charge. This is within the rating! We are going to force it to stop charging 20 times by warming up the temperature sensor.

We have choice of

* Meanwell Potted Bricks
* GroWatt

Meanwell Potted Bricks are known-Friend-of-Revolution (KFoR). GroWatt is what we will be using for activities moving forward, and it may have some more aggressive flyback. Nothing unreasonable... for a RELIABLE BMS (cough).

Any BMS needs to be able to survive
* Basic Flyback at time of OPEN (TVS bi-directional from Source to Source, or Blue to Black, or B- to P-)
* Basic Peak Current (Inrush or tap wires)
* Basic Burst Current (Starting Current or big push, order of 10 seconds)
* Basic Constant Current (Charging or Discharging Continuous)

This is most basic understanding of TRUTH and LOGIC and REASON across all MEN, WOMEN, CHILDREN of Earth.

So How do I know that is Truth?


If a BMS cant survive a basic inrush (momentary short or Peak) and it fails to mode of SHORT and it can no longer do its job of block discharge, well... now it is hazardous goods. It is no longer safety device.

If a BMS cant survive basic burst current (starting current) then everyone will hate it and it will cut out all the time, so there has to be a Continuous Rating and a different Burst Rating. You can not do burst for long periods

If a BMS cant survive basic constant or continuous current... well...

So it could be argued that a BMS does not have to deal with Burst, but it must
* Deal with Peak, Inrush, Short
* Deal with Continuous (so temp genreating)

So if Safety Device, it must know if it has failed or is going to fail. Most basic of temperature protection that costs $0.10 to add and makes all product better.

This is most basic of job it has. Its J O B is to cut charge or discharge so it HAS TO survive this. To survive this

* Resistive
* Inductive
* Capacitive

It has to have TVS Diode to sink flyback and it has to have shunt resistor to detect inrush.

* Nobody is running Resistive Load... so any argument to that is funny haha joke
* Everybody is running Capacitive Load... so we have to detect and survive that inrush... this is SHORT PROTECTION
* Everybody is running Inductive Cables... so we have to have Bi-Directional TVS diode to freewheel this flyback

Everyone knows this
DALY knows this... DALY Engineer knows this. It is DALY SALES GUY or DALY BUSINESS GUY who made decision to drive down cost below actual cost of Safety Device resulting in Unsafe Device which fails in a nearly undetectable way and leaves you vulnerable to fires at your house.

This is just talk that any Layman can understand. No Lawyer JumboMumbo. Just basics. Like Amazon Basics.

QC003 (unused) is now hooked up to the Banger. We are going to

* Confirm short circuit across outputs since Battery is at 53V and no cell is below LVC
* Start Charging at 20A, let temperature stabilize
* heat sensor with heat gun 20 times, force terminate discharge

But before that
I have to wire up my SPF 5000 ES with a NEMA 5-15 to provide that charging power.
* 20A * 50V = 1KW

This will be fine. I have never run a 5000ES off of 120 before, only 240!!! There are firmware settings to allow this and you have to derate the unit by 50%. This is because Current is Current, this is what it can handle... a given current. If you cut voltage in half from 240V to 120V, well... now you handling HALF the power

Simple math

So much disappointment :oops: :confused: :(

I wonder if DALY thinks this is how I want to spend my Saturday? Right? My one day I have off... where maybe I could be completing my project.. but instead I am doing their job for them

But pointless job... because no help. I am doing worse, I am doing "Wasted Work".

But worse
There are thousands, tens of thousands of these things floating around. Sold thru numerous retailers including Amazon. What a nightmare that is. Like Fight Club Nightmare, where Recall is needed but costs more than................

.... So we all know that there will never be a recall. That every one of these BMS's will remain in service. That we will see those random failures and fires... and EV and Electric will continue to get a bad name. People will continue to be scared

All Because?
* Someone wanted to save $4.20


I use this one long 14 AWG with no ground. Poor man make do... To perform test. This will carry one horsepower no problem.



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You no copy methods or burn house down!
This is 5KW device, not ok to hook up like this.

* methods == stuntman
* Graduate BSEE
* Graduate MSEE
* Work weapons 10 years
* Work startups 10 years

That means methods is Electrical Engineer with over 20 years industry experience + 30 years hobby experience. methods makes no fire that he does not intend to make.

* Knows Power
* Knows AWG
* Knows AC
* Knows DC

methods can wire your entire house, methods can build your entire electrical system... So do not copy unless you know what you are doing. This is PROFESSIONAL STUNT MAN showing how to OPERATE IN SIMULATED (this time real...) Emergency

* Work with what you have

See methods fixing super scary 1.2KW 600V Power Supply?


Take broken thing, make it work, super dangerous
Then, hook Arduino to it and remote control.
Then hook up to IoT waterproof systems, control over cell


So methods qualified for this work. You get qualified too!

Off to eat breakfast
Then strip wires
Then start test

That is the 600V Power SUpply I used to Validate the SPF 5000 ES

* Set supply to 420V
* Set current to max
* Attach to MPPT Solar Input

The 5000ES then MPPT's the supply to one of two Maximum Power Points
* Current
* Voltage

Everyone should know that there are not ONE, but T W O points of MPP in any solar setup. Anyway, this allows me to convert

420VDC * 1.8A = 756W ~= 1hp

From high voltage DC into high current dc... as the device charges my batteries at 58V

756W / 58V = ~13A Charge Current

Pretty Nice eh?
At the same time... brought up the unit. Made a bunch of videos. I have 2000+ videos on how to do all these things but they are all set to "unlisted" - so - they persist on the forum where I post them but you cant see them if you just go to my Youtube


You can see demonstrations like this