Old BMS General Thread

[qdos]

Thanks Peter I will do a teaser article as something coming up in the future then

Sorry I can't see your LEDs in the first 20seconds of the video I'll look toight when there's no light LOL

[retepsnikrep]

Sorry I can't see your LEDs in the first 20seconds of the video I'll look toight when there's no light LOL

Time for the laser eye surgery then They are there flashing away.

A newer version of the Master I'm still tinkering with the screen layout, and I've added the speed distance back in for testing.

www.solarvan.co.uk/bms/MASTER031008_V33.txt

Hmm now how do you provide a nice variable pulse output for the Master speed sensor test input?

I know write a little program for the Watchdog 08M chip on the Master board and connect a wire between J20 pin1 and J16 pin1 to send the test pulses into the Master to simulate different speeds! I'll do that tomorrow as I'm going to drink that bottle of wine now and get up at 5.30am for work

[GregsGarage]

Peter,

I have 4 battery boxes, so 4 temp sensors is just right. Speaking of temp sensors, found this report on a plug in Prius conversion that was completely destroyed by a fire from the battery pack. Interesting to note that the batteries were the A123 cells, although the problem appears to have been caused by a incorrectly assymbled connection, the heat generated caused a cell to rupture, spewing electrolyte and ...

... well best to read the report, Prius fire. BTW, its a 2mb pdf.

And I will finish off with one more link, haven't read all of it yet but looks good. http://www.maxim-ic.com/appnotes.cfm/appnote_number/3501

Anyway, I am now off to view this you tube video everyone is talking about!

EDIT; I have updated my EV photo album entry with some new pictures of the Fiat.

[retepsnikrep]

Yes, bad electrical connection causes fire familiar? Of course, and they cause hundreds of deaths worldwide every year, mainly in houses as we all know.

A few seconds spent checking tightness, alignment of EV high current connections is always worth while I'm pretty fastidious about this along with terminal cleanliness. I'll be checking mine for tightness after about a month in service and then at 6-12 monthly intervals, I'll probably clag a bog standard smoke alarm innards in the cell compartment as well.

Can't blame the Lithium, although many will sadly!

I like the Maxim chip, I've looked at it before though. The data comms looked too difficult for me, but be my guest and crack on

I like the new pics and can now put a name to that face from Scotland I like the angled on their side battery boxes, nice and easy to get to terminals.

[MalcolmB]

I'll probably clag a bog standard smoke alarm innards in the cell compartment

Brilliant! I've been racking my brains for ways of monitoring the battery pack in my fibreglass (and highly combustible) mini. Bleeding obvious innit

Love the paint job Greg. Far out

[retepsnikrep]

Love the paint job Greg. Far out

Where are my magic mushrooms I need those to work out what the hell is going on with the Master software

Been tinkering with speed and odometer today.

Thanks to Matt for his earlier help with the calculations.

Added a new piece of software for the Master board watchdog 08M chip.

www.solarvan.co.uk/bms/SpeedSensorTest6 ... 08_v01.txt

This provides simulated speed sensor pulses at 76/sec which equates to 60mph in the Insight.
This is fed into the speed sensor input via a single wire between J20 pin1 and J16 pin1, and allows checking/setup of the speedo function.
Other users will have to work out their own speed sensor pulse output per mile,
and adjust Master software to cope, however it seems to be working OK on the bench.

With simulated 60mph input odometer is clicking over at rate of a mile a minute

Seems accurate at the moment to +/- 3mph, hmm, should be able to do better than that

Still re-organising Master display, but Master software is about at the stage where I would be happy to run it in the vehicle.

There is lots of tinkering and smoothing off of rough edges I can do later, with addition of wh/mile and similar functions, but it's working well enough now after hundreds of hours of work for the actual basic installation IMHO Anyway I've got 5+ weeks before by charger arrives

Latest Master Software.

www.solarvan.co.uk/bms/MASTER051008_V34.TXT

[qdos]

LOL It's gone 11:30 Sunday night and I just turned all the lights off and I can just make out some little sparklies that look like random pixles on the beginning of the video so ok if that's them I can see them (just)

[retepsnikrep]

Are the carrots taking effect qdos?

Slightly neater and more logical display today.

www.solarvan.co.uk/bms/MASTER061008_V36.TXT

Software Todo list for next five weeks.

1) Add whmile (I've no idea about this at the moment, I looked at my old code from my MK1 BMS and can't follow my own ideas) Anyone want to chip in Actually thinking about it if I preserve the current consumed per mile somewhere I should be able to do that fairly easily. I'll look at it tonight.

2) Add error code storage, so errors which self correct whilst bms unattended are available for checking/examination etc later

3) General code tidy up optimisation/continues

Any other ideas for functions people would like in the MK1 Master software?

Graphs will be coming later in Master MK2 or daughterboard.

Peter

[qdos]

Would it be possible to link the data to a GPS/Sat Nav?

What I'm thinking is a means of indicating that you're not going to make the destination or you've oodles of juice to go quicker kind of thing. I was just pondering this the other day and reckon it should be possible and hey presto you just volunteered to do the sums LOL

[retepsnikrep]

Would it be possible to link the data to a GPS/Sat Nav?

Possibly if you're very clever, so that's me out Good luck with it though

I may add estimated miles remaining at current power consumption, I had that on the old BMS, i'll have to look at my code. That could be used with the GPS as that would tell you miles to detsination and you can see current performance and make the concious decsion to go faster/slower depening on amount remaining/power used for last mile/10 miles etc. I need whmile working first.

It may be possible to get the Master to output serial data that could be used by a GPS and possibly vice versa. I have no plans to do that at the moment though. I'll probably implement data logging and 433mhz wireless data exchange with my PC next.

EV Miles remaining is a bit of a fiddle/red herring in my hybrid as you just use more and more IC as battery gets lower. In the Honda Insight the IC always runs so you are never on pure battery power in an EV mode. The IC just uses less and less petrol as you offset the load with extra electrons So as battery soc goes down fuel consumption goes up. Miles remaining for me is unlimited but mpg will vary depending on amount of wh/assist used. On short journeys say less than 20 miles a large amount of assist could be used, equating to 150mpg+ economy. On longer journeys less assist for longer periods may mean 125mpg+ for several hundred miles

That's the plan/hope anyway

I'm thinking of implementing a second display screen instead of cramming everything on the single screen/page. Keep the basics on page 1 and then either set it to display them alternately or 2nd page only at touch of a button. I'll have a fiddle about with that over the comming weeks.