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amund7 / OZ890-BMS

Arduino interface for OZ890 ebike BMS. Includes LCD display, WIFI UDP broadcast, and calibration + settings program
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schematic / wiring diagram, partlist #1

Open ghost opened 8 years ago

ghost commented 8 years ago

very interesting project, whould be great if you can add a partlist & schematic / wiring diagram

// J

amund7 commented 8 years ago

That's a great idea, will try! At least the parts list, wiring is pretty self explanatory.

On Mon, Jun 13, 2016 at 3:13 AM, j-trashcan notifications@github.com wrote:

very interesting project, whould be great if you can add a partlist & schematic / wiring diagram

// J

— You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub https://github.com/amund7/OZ890-BMS/issues/1, or mute the thread https://github.com/notifications/unsubscribe/AAqfKYXzgR1X__0bQlT0zgP6aEvIz0RRks5qLK69gaJpZM4Iz7o3 .

ghost commented 8 years ago

lovely, you can be sure that there are lots of people out there looking for exactly such a project regarding threads on german ebike forums and endless sphere

amund7 commented 8 years ago

Feel free to spread the link to this project, there is not much code on the internet for this BMS.

ghost commented 8 years ago

already in progress ;)

am i assuming right, that it whould be a board like this

https://www.adafruit.com/products/2488

with something like

http://www.ebay.com/itm/Ocular-240X160-Monochrome-Graphic-LCD-Display-Module-3-x4-Arduino-Raspberry-Pi-/291730947325?hash=item43ec84fcfd:g:ywgAAMXQiNdReWyK (just with a matching resolution)

whould be fine?

amund7 commented 8 years ago

Just made a quick wiki page, hope it helps.

https://github.com/amund7/OZ890-BMS/wiki

Let me know if you need more info.

ghost commented 8 years ago

Thats a great start, thank you very much :) Will let you know about progress, also there are already others from a german ebike forum who spy on this project

amund7 commented 8 years ago

Updated the wiki with some more info. Please spread the link!

ghost commented 8 years ago

did so already :) and ordered arduino stuff yesterday, will do my best to contribute to the wiki docs

thanks a lot for your support & time to add the wiki stuff!

ghost commented 8 years ago

hardware arrived during the last days, i think i´ll give it a first shot during next weekend. will let you know about progress :)

amund7 commented 8 years ago

Cool! Let me know if you have any problems or questions. Do you have the same BMS board as me?

Phil1988 commented 8 years ago

I think he might have an "smart BMS" from here https://bmsbattery.com/bmspcm/330-smart-bms-513-cells-in-series-bms-pcm.html and is looking for an open source adapter to read and program this thing.

As j-trash is saying - there are really a lot of people looking for a device that can communicate/programm this BMS.

Would be great if you can post some pictures or make a short video to explain your progress and what works. Your wiki is a good start.

There are some guys around that could help you. Cheers!

amund7 commented 8 years ago

Let me know what you need, and I will try to provide it.

Currently, the settings I needed works (calibrate voltage was the hardest, because it needs the password) Many settings I have not implemented, but they should be very simple to implement based on the code I have.

The BMS and BMS-LCD works pretty good, except for the Ampere measurements.

Also, since calibrating the voltage I noticed that sometimes the BMS card will freeze completely, it seems to get stuck not replying to I2C requests, and also doesn't do charge or discharge cut-off in case of over/undervoltage, until I disconnect the batteries and balance cords and reconnect. The danger is that unless I detect the Arduino not refreshing the values, I have no way of knowing it's frozen. I am wondering if it is because I've fiddled with too many settings, or the board is damaged physically/electrically. I know I've broken the rule of not leaving the balance leads when the main battery leads are disconnected - fiddling with this it is very easy to get wrong.

I will buy several new boards and see if the problem is only with this board, or with my settings.

Sorry that was a bit off topic, but bottom line is I use this BMS every day, and it works. The code and projects of course need a lot of cleanup and more features.

Also, I discovered WIFI is a bit stupid, it means I can't use the phone for maps or anything else that needs internet. So I am pondering to switch to bluetooth.

Phil1988 commented 8 years ago

Its completely not off topic.

Its important to know what works and what is problematic.

What you write sounds like you can already program this BMS with your setting (without their I2C adapter). Is this true? So you can set the bleeding voltage, overcharging limits etc.?

Your problem with the phone that cant be used while looking at the data can easily be solved with wires to annother arduino and displayed at the LCD. Another solution is to use a HC05 (or HC06) BT module and an app for the smarphone. I'm using an HC05 for 3 years wouthout any problems on an arduino mini.

The more challening part fmight be to get this think working as BMS programmer.

Btw: If you live in germany it would be great if you can tell me before you place the next order... maybe we can do a collective order ;)

amund7 commented 8 years ago

Hell yeah it works!

Upload the BMS-Settings to any arduino and run it (no need for a BMS board), you can see the menus and what they contain. It's a bit messy and it doesn't have all the settings as menu options,, but like I mentioned earlier, the hardest part was getting through the password protection to set the cell voltage calibration (which was CRAP from factory), and that works.

I have not implemented the low/high voltage cutoff settings, but those should be easy.

I agree that the wifi problems are solved by using an LCD. But the LCD I have is unusable in sunlight, and also finding a cover/box for it is proving hard.

To be honest I am moving in the direction of no Arduino at all (except for programming the BMS). The info it provides while biking & charging is info I needed in order to learn about LIPO batteries and the BMS, but now I feel I know enough. I am going to try to connect a 5 led bar graph to the 5 led outputs of the BMS.

I live in Norway, will build a few BMS's for me and my friend. We are trying to bulid several self-contained battery boxes with 2 lipo bricks, BMS, charge plug and XT90 for the bike. That way they can be quickly swapped around, charged, or put in the backpack or on our bikes.

jcmaquet commented 7 years ago

hello good work, I will test it soon ! about current measurement on smartbms, it use the rdson on the mosfet as shunt. it's not accurage and can broke the chip in some case. I have added a shunt on board to avoid somes issue. more info here. http://vae-tech.forumactif.org/t61-smartbms-oz890-modification-shunt-externe