Old BMS General Thread

[retepsnikrep]

In preperation for the multiple temperature sensors on one input feature, which I'm busy incorporating into the Master here is some updated BMS config software.

This allows you to attach each sensor/or the wires to it to the Master in turn, and it then reads the unique serial number from the I2C DS18B20 device. It should work with any other I2C device from the same family as well. It can only read one sensor at a time, and if there is no/faulty sensor etc you will get garbage displayed.

This 8 number serial is then noted down by the user, and will be added by them to the Master software when released to enable access to each temp sensor individually.

Greg, you need to use this to get the unique ID's for each of your temp sensors.

www.solarvan.co.uk/bms/BmsConfig300908_v06.txt

The upgraded Master software is coming and is just about there with this new feature. Lack of variables is a problem now and I may have to re-wire/reorganise soon to make it a bit easier to follow and more effcient.

When the Picaxe 28X2 part is launched in a few weeks the variable problem should be over as it has double the capacity

[mikep_95133]

Mike

They are actually in parallel with it if you look closely, so each gets the same current.

Peter

Especially if I use a more current schematic. Master 100708.jpg is what I was referring to.

I thought I had downloaded the last few versions, but did not. The latest appears to be Master080908.jpg. It shows them in parallel. Is this the latest?

Sorry for wasting the bandwidth.

Mike

[retepsnikrep]

Yes that's the latest Master schematic.

[GregsGarage]

Greg, you need to use this to get the unique ID's for each of your temp sensors.

www.solarvan.co.uk/bms/BmsConfig300908_v06.txt

The upgraded Master software is coming and is just about there with this new feature. Lack of variables is a problem now and I may have to re-wire/reorganise soon to make it a bit easier to follow and more effcient.

When the Picaxe 28X2 part is launched in a few weeks the variable problem should be over as it has double the capacity

Brilliant, although I have yet to order the rest of the parts required to make the master PCB. In the process of drawing up a list, I thought a database would be a good idea, any changes to parts could be reflected on the database and a revised shopping list could be printed. I now have 2 tables, one for the Master pcb part list and one for the supplier order codes. Might be a bit of overkill, but I am using OpenOffice Base, so will post the file when it is finished.

By that time Picaxe 28X4 and a full colour display might be released!

[retepsnikrep]

I now have 2 tables, one for the Master pcb part list and one for the supplier order codes. Might be a bit of overkill, but I am using OpenOffice Base, so will post the file when it is finished.

Good man Greg, I'll leave that with you

Upgraded Master Software is working and I now have the temp from the sensors in my two battery blocks displayed Greg, we will need to tweak it a bit for your four sensors. Basically duplicate my two sensor code.

I've also just about finished the high current connections on my battery blocks. The final interrupt driven digital slave software with 10x oversampling just has to be loaded in and they are done. Hooray Should finish that today. I've binned the power saving feature at the moment as I was getting delayed trying to save a few ua of power, when I'm only using 1ma anyway or 1000hrs for 1ah Need to get a grip. I'll fiddle with that later once car is on road.

Edit Finished high current Anderson connectors and re-programmed slaves with latest digital slave software. This is the final version of the digital slave program before I actually get to test it in the car!! Seems to work ok on the bench.

www.solarvan.co.uk/bms/SLAVESIMPLEDIGIT ... 00BAUD.TXT

I have used some plastic nut covers on the cells to help prevent the live terminals breaching the plastic cover, it also gives a bit more room under the cover, so I may not need the fans. Also the cover forms part of the floor of the little cubby hole in the rear of the Insight so it may be loaded slightly, this avoids any weight pressing on the circuit boards.

My mate Roger is making me some more covers slightly thicker and with deeper sides as I have mangled these about during this prototype work. They are fine for this MK1 phev version but I am aiming to get it looking as good as possible.

www.solarvan.co.uk/bms/BatBlocks1.jpg

Each block has two D-Sub data connectors and one or more high current connectors.

The front block (at rear in photo) has one x two pole Anderson connector + & -

The rear block (at front in photo) has two x two pole Anderson connectors
+ & - as above but also another break in the circuit which corresponds to the Insight OEM main switch on the nimh pack.

So the configuration of the Li-fepo4 pack connectors/bcm taps etc is identical to the oem nimh pack


Edit Back to work now so just software tinkering for the next few days, I'm rapidly reaching the point where I need to install the video display and buttons in the car and route the cables to the back ready for install day. Any way I'm off for a beer

[retepsnikrep]

Quite a re-organisation of Master software today.

Declared some different global and local variables so I could free some up for the speed/distance/wh stuff. Also deleted global display routine, and now each subroutine displays it's own data when called rather than trying to save it all for one display section later. I'm not a software engineer or anything in fact so no wonder I was barking up the wrong tree

Anyway this means variables can be released for other uses.

www.solarvan.co.uk/bms/MASTER021008_V31.TXT

Added the multi temp sensor code which works nicely I don't know the limit but each sensor takes about a second to access so more than about 5 would be a bit time consuming. I run the temp subroutine once a minute. I have two sensor at the moment one per block. Greg, you should be able to see in the Master code where to add your temp sensor data obtained using the BMS config software, I added the code for four sensors but rem'd two out

Couple of photos of latest BMS screen showing some new numbers.

www.solarvan.co.uk/bms/Bms021008.jpg

Cells have stood for a few days now and are within 80mv of each other across the pack. The new info is

1) "Df" which is the difference betwen the highest and lowest cell V.
2) "Hi" which is the highest cell V
3) "Lo" Which is the lowest cell V

Rest is all self explanatory I hope.

Two temps are now shown on screen, one for each battery block. Greg, I think you may have 4 or 5?

I've just ordered a Zivan NG3 144v 15A charger which should give me a <3hr recharge capability if the cells can take it. Lead time is 6 weeks though so install may now be mid november! Still lots of time for bench testing and software development.

Another youtube video to follow shortly

http://www.youtube.com/watch?v=2oN97Zgg4DY

[mikep_95133]

Fantastic work Peter!

I'm making the parts to mechanically place 3 Thundersky cells in my nicad pack. For the immediate future they will have a basic analog BMS board watching over them until your boards get here.

Can't wait to start testing!

Mike

[qdos]

Superb stuff Peter!

Only negative is that the video is black for the first 25 seconds and I had assumed something was wrong with YouTube as you are talking about what we can see when it's a black screen.

I'd really like to have something in Plugged In about this please write something when you feel you can.

[MalcolmB]

Cool! (as my son would say) If you look carefully Kelvin you can see the indicator LEDS on the cells cycling on and off around the pack.

[retepsnikrep]

I'd really like to have something in Plugged In about this please write something when you feel you can.

I will later when it's all done and working correctly, hopefully

Feel free to nick bits from here for a heads up in Plugged in.