DIYBMS v4

lanzecki · 2019-11-07T20:26:33.762Z

Hi Stuart, thanks for the quick consideration of my issues. I do recognise that you don’t have to, and aprechiate the effort you’ve put into all versions of your BMS, making it available to us, and providing support.

I’ve had 7s pack (just 1P) during testing. I wonder if that’s potentially the cause?

I charged the 7s pack and left it all plugged in for a day or so. Andafter that I started to take some mha from the pack (down to 4.0V). That’s when it started locking up.

I then left the pack alone, connected to the BMS’ and controller, feeding data to the database. I did this for 2-3 weeks. Randomly BMS’ would lock up.

A few days ago, I removed the last BMS to reduce the Pack to a 6S pack (Still waiting for a charger to arrive that will cope with 7s.

Once down to 6s, I started charging, and noticed the BMS balancing, and not locking up. It did lock up only once during charging. I did a small discharge and don’t recall a lock up, but I only discharged for a few hours, and at a very low current.

Once charged closer to full (About 4.1V per Series). I left the pack alone for a while. I was getting lock up’s as usual.

Generally I find that it’s the first 3 BMS’ that lock up. Be it one or two. Never more then 2. Less often it’s cell 5 or 6.

I cannot tell you or a definite way to get it to lock up.

Note that I’ve used the pre compiled code. I work in IT, and wasn’t able to work my way thru the ‘manual’ way to upload it. I will admit that I didn’t break by arse to compile the code as there was precompiled code available.

This generates a question. Is the pre-compiled code an older version then the code that requires compiling? Maybe I should bite the bullet and work out how to do it with the un-complied code… Problem is I have no idea where to start, and cannot find an idiots guide.

Thanks.
Simon

stuart · 2019-11-08T08:57:37.215Z

lanzecki:

Is the pre-compiled code an older version then the code that requires compiling?

That code is the current version.

I’ve never had the modules lock up during normal usage, on a couple of occasions I’ve had a module hang with the green light on - normally during me plugging in cables or randomly unplugging stuff.

I think this happens at the exact same time as the module is trying to take a voltage reading - it puts the LED on, starts the reading process but never finishes. The ATMEL chip hasn’t hung or the in-built watchdog timer (8 seconds) would have rebooted the chip.

I’m running a 4S1P test environment on these at the moment and left them running. Internally the code does keep a count of any corrupt data packets that the modules receive, I’ll add some code to expose this on the web page just to ensure its not a data corruption issue.

lanzecki · 2019-11-08T23:41:54.792Z

Thanks Stuart,

You are a star. Bet you will have to wait a while though

stuart · 2019-11-11T09:46:12.485Z

lanzecki:

You are a star. Bet you will have to wait a while though

I’ve left the BMS running for a week to try and catch a lock up. I finally got 1 module to hang at some point yesterday.

What I noticed is that the module before the one that locked up received a corrupt data packet (the only 1 in a week of running). I’m thinking that this packet was then passed down the chain and the next module to receive it locked.

More investigation to do, but at least I’ve got a train of thought to work with.

Edoardo_Conti · 2019-11-12T00:08:40.446Z

Hi, great job Stuart. Congrats!

I’ve been reading about this project for a while and I decided to build my own. I’ve been meaning to buy the PCB from jlcpcb with the “SMT Assembly” service (for both save money and lack of right equipment).

Unfortunately it requires two additional files besides the Gerber file:

BOM
CPL (Pick&Place File)

The first one is available thanks to Stuart but I didn’t find CPL anywhere.
Is it possibile to get it?

Robert.Wall · 2019-11-12T12:23:46.907Z

3 posts were split to a new topic: DIYBMS - Active Balancing

super2222 · 2019-11-12T00:22:51.945Z

there you go just make shure everything is ok
v4 edit.csv (3.9 KB) v4-top-pos.csv (1.7 KB)

Edoardo_Conti · 2019-11-12T09:18:40.909Z

Thank you so much!

Unfortunately there are several components unfound. Do I have to search for alternative components with specs as close as possibile to the original ones?

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neil_l12 · 2019-11-12T14:30:38.399Z

Hi,

@stuart I know you’re working on a c_sen option but I wanted to sound this out with you, or anyone for that matter…

So the PCF8574 is I2C, would it be possible to connect up an external ADC like the ADS1115 which can do differential measurements. The ADS1115 would measure one of those 50/100A (or bigger) DC current shunts which output up to 100mV which I believe would be suited to the ADS1115 at x16 gain…

Edit: I checked the I2C addresses for the PCF8574 and ADS1115 and they should be happy

Untitled%20Sketch_bb1239×903 70 KB

stuart · 2019-11-12T15:01:46.221Z

neil_l12:

Edit: I checked the I2C addresses for the PCF8574 and ADS1115 and they should be happy

I can’t see a reason that this won’t work - obviously it would be the ESP that would need its code changing to talk to the new i2c device. Should be easy to tap into the i2c bus.

stuart · 2019-11-12T15:02:40.734Z

Did you upload the BOM and also select the LCSC part number from the drop down list ?

Edoardo_Conti · 2019-11-12T18:40:52.797Z

Hi, I uploaded the Gerber file, selected “SMT Assembly” with “Assemble top side” option.
Next I uploaded the BOM and the CPL files provided by @super2222. Sorry, what drop down list are you referring?

Now it seems that a part of easyeda services is down (I write from Italy) , so I can’t replicate the steps.

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Jonisonveapa · 2019-11-12T20:45:02.107Z

hello
i have 10 attiny chip for sale if anybody need them ~?
at cost im in the uk so delivery will be fast

Shawn_Maker · 2019-11-12T20:47:17.922Z

Thank you so much for creating this Stuart. It is amazing! I am having trouble getting the modules to communicate with the controller. In your video I heard you say you are not supporting 32 bit right now. I got a D1 V3 for the controller. Does that matter? I have tripple checked my parts, joints, wiring, but it still won’t connect. Even built a couple boards and controllers and get the same results. The web server runs pretty slow too. I’m thinking it is probably the wemos. Any thoughts? Does that even make sense? Thank you all so much. Your inputs here and videos have been priceless.

super2222 · 2019-11-13T00:36:18.339Z

Edoardo_Conti:

Sorry, what drop down list are you referring?

When you click on the search (on the right of no part selected), you can search for parts try to use basic parts when possible( way cheaper)

Also I forgot to say that I didn’t send my order yet hopefully everything is ok in the files that I did put. I did use kicad to generate those files

2019-11-12%20(2)_LI1733×672 102 KB

Stingy49 · 2019-11-13T05:12:18.892Z

Hey @stuart ,

I noticed the website always has a horizontal scrollbar in chrome and sometimes experiences a flickering scrollbar. I was able to fix this by changing the css style sheet. From line 28 .page {clear:both;.... I changed the margin from 5px to 0px and this seemed to fix it.

I made the modification to the css_1.h on my local version and confirmed the fix. I’ve made other changes so I don’t want to push to git and dirty the code. Feel free to confirm this and update git yourself (or anyone for that matter )

-Derek

Edoardo_Conti · 2019-11-13T08:59:44.936Z

I figured that’s what stuart is referring. Thank you so much.

CrAzYDr1veR · 2019-11-13T16:32:36.131Z

time to weld…

IMG_50892448×3264 2.42 MB

stuart · 2019-11-14T16:57:13.820Z

Have you built a v3 or v4 board @Shawn_Maker ?

Shawn_Maker · 2019-11-14T19:54:37.851Z

@stuart it is a v4board. I ordered another D1, older version, and it is doing the same thing. I’m starting to wonder if it is my router. Sometimes the css doesn’t load. I have tried it on Chrome, Edge, Firefox and even internet exploder. I have even tried it right next to the router. I used the compiled files to flash the D1 and the module and get no errors. Module even flashes green every so many seconds. I thought it may have been the D1.