Multi-Cell Slave-Version 2

Threads relating to the BMS system begun by Peter Perkins

Moderators: GregsGarage, retepsnikrep

User avatar
retepsnikrep
Posts: 1387
Joined: Sat May 26, 2007 4:50 pm
Location: North Yorkshire England
Contact:

Re: Multi-Cell Slave-Version 2

Postby retepsnikrep » Sat Apr 21, 2012 3:47 am

Not tested or checked in any way.
Attachments
SLAVE_V12_28032012_12F1822.zip
(1.52 KiB) Downloaded 399 times
Regards Peter

Two MK1 Honda Insight's. One running 20ah A123 Lithium pack. One 8ah BetterBattery Nimh pack.
One HCH1 Civic Hybrid running 60ah A123 Lithium pack.

GregsGarage
Posts: 870
Joined: Tue Apr 01, 2008 5:27 pm
Location: Galashiels, Scottish Borders
Contact:

Re: Multi-Cell Slave-Version 2

Postby GregsGarage » Mon Apr 23, 2012 3:53 pm

Finally I was able to try and program these boards. It mostly seems to work. :? First problem I had was that I took the boards home at the weekend and realized that I had left the programmer at work. Then it wouldn't recognize the part id of the 12F1822, so after a bit of messing around with updates I finally got there. I was just using some male headers on the end of the programmer and pressing it onto the board. Programming wasn't very consistent, sometimes it worked and sometimes it didn't. I suspect we need to make up a progamming attachment with some pogo sticks to get a better electrical contact. I will make up some more boards with better soldering and try again.
Greg Fordyce

Daewoo Matiz
http://www.evalbum.com/4191

mikethebike3
Posts: 27
Joined: Wed Sep 17, 2008 3:19 pm
Location: NE Norfolk, UK

Re: Multi-Cell Slave-Version 2

Postby mikethebike3 » Mon Jul 16, 2012 10:02 pm

Greg

I realise this is an old thread but can I ask a couple of questions regarding the status of the BMS?

I'm about to order 36 of the new CALB CA180FI cells to convert my Seicento from LA to LiFePo4. The warranty requires that charging and discharging are carried out using a "high class Balancing and Monitoring System", and I well remember a year and a half ago reading all the postings on the BMS mainly between you and Peter.

It seems the new Calb cells perform very well, and some believe that balancing while charging may not be necessary, so long as cell voltages are carefully monitored during charge and discharge. I was originally planning a version of your LTC6802-2 monitor until I heard from CALB's EU agent that top end balancing during charging is a requirement to comply with the terms of the warranty, and so it seems I will need a per cell balancer and monitor which I'm presuming this slave board was intended to do.

I also read that you and Peter had changed to a Maximite in place of the original master, but I would really like to use an Arduino as I have used these for a low power distributed data acquisition system for our wood boiler, rainwater and solar thermal panels, using a serially connected IPAQ PDA for data display and recording. Is there buried among all the postings a summary of what this slave board can do, and (I know I'm dreaming ..) an outline of the master-slave interface and protocol? Didn't you get some slave PCB's made up? I'd really like to display all my cell voltages in the car so a simple thing like MiniBMS isn't for me, but at the same time I'm probably not up to reinventing yet another wheel when so much good work has already been done.

So many questions, sorry, but any pointers would be much appreciated!

Thanks

Mike

GregsGarage
Posts: 870
Joined: Tue Apr 01, 2008 5:27 pm
Location: Galashiels, Scottish Borders
Contact:

Re: Multi-Cell Slave-Version 2

Postby GregsGarage » Mon Jul 16, 2012 10:33 pm

Hi Mike,

While you were posting this I was posting in your CALB thread. :lol: :lol:

For the moment this board should be considered dormant, no software has been written for it yet. But really the 2 main changes for this board was smaller size and reduced component count, otherwise functionality was to be the same. Have a look at the existing slave software, it is well documented, including master-slave comms, and would be the basis for the software for this board. All comms are just simple serial commands so an Arduino could be used for the master. There is some C code posted somewhere that would probably give you a start in the right direction (Arduino is very similar to C). It would be nice to have a Arduino based master, but it won't be me that does it. :lol:

The Maximite master hasn't been done yet, I'm planning on using that for the new 6802 slaves. Too many things on my todo list. :(
Greg Fordyce

Daewoo Matiz
http://www.evalbum.com/4191

mikethebike3
Posts: 27
Joined: Wed Sep 17, 2008 3:19 pm
Location: NE Norfolk, UK

Re: Multi-Cell Slave-Version 2

Postby mikethebike3 » Tue Jul 17, 2012 11:20 am

Hello Greg

My you do flit around the forum, don't you! :o

Thanks for the heads up, I didn't want to wade through all the earlier postings only to learn later that everything had changed, but if the principles are still the same then it'll be time well spent. I'm still keen to build my own distributed BMS, based on an Arduino master and IPAQ hmi if possible, and I could ask many questions about the best choice of slave board but I'll keep these until I've learned more by reading the posts. Do you perhaps have a sample slave PCB I could purchase to give it an initial whirl?

The IPAQ is great btw in that you get a low cost, low power colour touch screen with serial port (to the Arduino), SD slot for data storage, and a CF slot for a wifi card which means I can see what's happening from any of the PC's on our home network via VNC. It works well on our eco data acquisition stuff, but I guess everyone will have their own way of doing things. :D

Thanks anyway for your feedback!

Mike

GregsGarage
Posts: 870
Joined: Tue Apr 01, 2008 5:27 pm
Location: Galashiels, Scottish Borders
Contact:

Re: Multi-Cell Slave-Version 2

Postby GregsGarage » Tue Jul 17, 2012 8:56 pm

mikethebike3 wrote:Do you perhaps have a sample slave PCB I could purchase to give it an initial whirl?


I do have some of the Ver 2 in this thread, but I would rather concentrate on the 6802 boards instead. When I get those I can send you some. Itead does them in batches of 10 and getting a few out for testing would be good. I plan on first building the board without the 6802 chip so that I can test the slave to master communications. My goal is to get reliable data transfer with boards mounted as far as possible from each other in a EV. Noise is the biggest problem. If your EV is still on the road you could help with testing. We can simulate cell data in software and after that part is proven then move onto soldering on the 6802 and do real cell measurements. These boards will be monitoring only, no balancing at all. I want to keep these as simple as possible. The person who I got the 6802s from tried to bring a fully fledged bms based on them with balancing to market and in the end shelved the project. It got too complicated to manufacture. I don't want to repeat that so the design has lots of ideas to make it simpler. For example each 6802 can measure 12 cells around 50 times a second and can support data transfer rates of 1mhz. I am going to measure cells once a second and slow down data transfer to 9600 baud tops, could be lower. Anyway I better get cracking on with Kicad and get the board routing finished. :shock:
Greg Fordyce

Daewoo Matiz
http://www.evalbum.com/4191

mikethebike3
Posts: 27
Joined: Wed Sep 17, 2008 3:19 pm
Location: NE Norfolk, UK

Re: Multi-Cell Slave-Version 2

Postby mikethebike3 » Wed Jul 18, 2012 11:56 am

AISI, the issue is whether or not I MUST have an active BMS for warranty, and as you know, on the Calb thread Beemer started, things are getting a little heated....

But ignorance is bliss, and I don't have the experience to join in the "BMS or not" issues, so for me it's crystal clear: Calb require active BM and I must therefore comply. Unless that is they can be persuaded to relax their requirements (which frankly would amaze me), so as you can see on the other thread, I've emailed to ask them to join in the discussion (yeah, right ....).

The upshot of this is that (unless there's a Calb capitulation) I'm going to need top balancing on charge and this means that a (passive) 6802 based system sadly won't cut the mustard. Which takes me back to an active distributed BMS ....

I like the newer 12F1822-based slave which you discuss on this thread, and a per-cell PCB version of this would be my preference, but, IIUC, to program this (I like to twiddle...) I'd need the pbp Gold Edition which at £172 is way too expensive just for twiddling. The student edition at £32 is much better and seems at least to support the 12F683 which would be OK, but I've emailed Crownhill for clarification.

Meanwhile, I'll keep studying these BMS threads :roll:

Mike

mikethebike3
Posts: 27
Joined: Wed Sep 17, 2008 3:19 pm
Location: NE Norfolk, UK

Re: Multi-Cell Slave-Version 2

Postby mikethebike3 » Wed Jul 18, 2012 12:36 pm

Bummer!

Crownhill recommend Proton Development Suite at £120 incl, although it does both 683 and 1822. Otherwise only Gold at £172 does 1822 (but not 683 strangely..). I'll take a look at alternatives - I remember using JAL (Just Another Language - a free Pascal-like compiler for PICs) a few years back which was excellent, but whether it's up to the task (or can be used with either chip) I don't know. :(
Back ont't internet .

User avatar
retepsnikrep
Posts: 1387
Joined: Sat May 26, 2007 4:50 pm
Location: North Yorkshire England
Contact:

Re: Multi-Cell Slave-Version 2

Postby retepsnikrep » Wed Jul 18, 2012 2:46 pm

The pbpgold edition does do the 12F683 :D
Regards Peter

Two MK1 Honda Insight's. One running 20ah A123 Lithium pack. One 8ah BetterBattery Nimh pack.
One HCH1 Civic Hybrid running 60ah A123 Lithium pack.

mikethebike3
Posts: 27
Joined: Wed Sep 17, 2008 3:19 pm
Location: NE Norfolk, UK

Re: Multi-Cell Slave-Version 2

Postby mikethebike3 » Wed Jul 18, 2012 3:29 pm

Reply from Crownhill:

Hi
we would recommend you purchase, Proton Development Suite
both the 12F683 and the 12f1822 are supported, by this compiler.

http://www.crownhill.co.uk/level3.php?cat=1&sec=1

there is a forum for technical support
http://www.protonbasic.co.uk

PBP student version supports only a few PICs and does not support either device that you mention

The silver edition supports the 12F683 but not 12F1822
The gold edition supports the 12F1822 but not 12f683

regards

Beryl

Sigh..... but of course I know you know better Peter! In any case I didn't realise when I posted that ProtonBasic isn't pbp anyway :(

Either way, it's still too expensive I'm afraid. JAL2 looks good though, apparently it also supports both your favoured PIC's, and it's freeeeeeee! :D


Return to “BMS thread”

Who is online

Users browsing this forum: No registered users and 14 guests