Here you go https://github.com/chrskly/electric-mus ... in/bms/src
[WIP] 1965 Ford Mustang
- rstevens81
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Re: 1965 Ford Mustang
There are some things to think about in allowing a BMS to control contactors and BMS code in general ....
1. Given that car is a very electrically and efm noisy environment a watchdog in the code is imperative because if the chip locks up you loose BMS, so therefore a watchdog to reboot it in that event is imperative.
2. The behaviour of the watchdog is also important...i.e. if it were to lock up and reboot what would happen would the contactors open and then close again? Under load this would substantially reduce the life of the contactors even the big ones. That's not all of the failure modes but a big one to illustrate the point.
3. Opening of contactors under load is always going to be bad for them and everything connected as electricity under load is like flowing water through a pipe if you suddenly stop it in a pipe you get hammershock the clunk noise you hear in pipes if you have an old house, in electrics the inductance of the circuit (wires) will try to raise voltage whilst you disconnect to make a bigger spark on the contactor, how big of an effect this is I don't know but point was also that a false flag will substantially reduce life of contactor.
I am aiming for a different approach it may not be right but is simpler in my mind as the simpler it is the less we have to think this may or not be useful...
1. Contactors controlled by VCU, when starting the switch on process just add a line of code the check the voltage dela...tbh it probably can be quite simple in that if your cell voltage delta is above X mV (of all 192 cells) you go into error or warning state and you just chech for error or warning before switching on.
2. If so etching goes wrong you enter a warning state a buzzer sounds if after 10 seconds (arbitrary to allow you to pull to side of road and switch off ignition) if after this X seconds the inverter is commanded to shut down and then commanded to open contactors.
Although this isn't perfect what situations would 10 seconds not be enough and if so could you skip the warning stage and go straight to powering down inverter?
Hope this is helpful in someway ... It all stems from the age old problem who is the biggest master BMS or VCU/inverter? You sorta have to choose 1 and live with the consequence and work round it to the best you can i.e. if you were to choose BMS as master it would tell the inverter to shutdown X seconds before it would open the contactors.
1. Given that car is a very electrically and efm noisy environment a watchdog in the code is imperative because if the chip locks up you loose BMS, so therefore a watchdog to reboot it in that event is imperative.
2. The behaviour of the watchdog is also important...i.e. if it were to lock up and reboot what would happen would the contactors open and then close again? Under load this would substantially reduce the life of the contactors even the big ones. That's not all of the failure modes but a big one to illustrate the point.
3. Opening of contactors under load is always going to be bad for them and everything connected as electricity under load is like flowing water through a pipe if you suddenly stop it in a pipe you get hammershock the clunk noise you hear in pipes if you have an old house, in electrics the inductance of the circuit (wires) will try to raise voltage whilst you disconnect to make a bigger spark on the contactor, how big of an effect this is I don't know but point was also that a false flag will substantially reduce life of contactor.
I am aiming for a different approach it may not be right but is simpler in my mind as the simpler it is the less we have to think this may or not be useful...
1. Contactors controlled by VCU, when starting the switch on process just add a line of code the check the voltage dela...tbh it probably can be quite simple in that if your cell voltage delta is above X mV (of all 192 cells) you go into error or warning state and you just chech for error or warning before switching on.
2. If so etching goes wrong you enter a warning state a buzzer sounds if after 10 seconds (arbitrary to allow you to pull to side of road and switch off ignition) if after this X seconds the inverter is commanded to shut down and then commanded to open contactors.
Although this isn't perfect what situations would 10 seconds not be enough and if so could you skip the warning stage and go straight to powering down inverter?
Hope this is helpful in someway ... It all stems from the age old problem who is the biggest master BMS or VCU/inverter? You sorta have to choose 1 and live with the consequence and work round it to the best you can i.e. if you were to choose BMS as master it would tell the inverter to shutdown X seconds before it would open the contactors.
Rule 1 of EV Club is don't buy a rust bucket....
Which rule does everyone forget
Which rule does everyone forget
- chrskly
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Re: 1965 Ford Mustang
Hey,rstevens81 wrote: ↑Sat Mar 11, 2023 12:06 pm There are some things to think about in allowing a BMS to control contactors and BMS code in general ....
1. Given that car is a very electrically and efm noisy environment a watchdog in the code is imperative because if the chip locks up you loose BMS, so therefore a watchdog to reboot it in that event is imperative.
2. The behaviour of the watchdog is also important...i.e. if it were to lock up and reboot what would happen would the contactors open and then close again? Under load this would substantially reduce the life of the contactors even the big ones. That's not all of the failure modes but a big one to illustrate the point.
3. Opening of contactors under load is always going to be bad for them and everything connected as electricity under load is like flowing water through a pipe if you suddenly stop it in a pipe you get hammershock the clunk noise you hear in pipes if you have an old house, in electrics the inductance of the circuit (wires) will try to raise voltage whilst you disconnect to make a bigger spark on the contactor, how big of an effect this is I don't know but point was also that a false flag will substantially reduce life of contactor.
I am aiming for a different approach it may not be right but is simpler in my mind as the simpler it is the less we have to think this may or not be useful...
1. Contactors controlled by VCU, when starting the switch on process just add a line of code the check the voltage dela...tbh it probably can be quite simple in that if your cell voltage delta is above X mV (of all 192 cells) you go into error or warning state and you just chech for error or warning before switching on.
2. If so etching goes wrong you enter a warning state a buzzer sounds if after 10 seconds (arbitrary to allow you to pull to side of road and switch off ignition) if after this X seconds the inverter is commanded to shut down and then commanded to open contactors.
Although this isn't perfect what situations would 10 seconds not be enough and if so could you skip the warning stage and go straight to powering down inverter?
Hope this is helpful in someway ... It all stems from the age old problem who is the biggest master BMS or VCU/inverter? You sorta have to choose 1 and live with the consequence and work round it to the best you can i.e. if you were to choose BMS as master it would tell the inverter to shutdown X seconds before it would open the contactors.
thanks for the input. Definitely happy to hear all perspectives on this. I'm just figuring stuff out as I go.
1. Yeah this is a good point. The pi pico has support for a watchdog. I'll add this in. Thanks.
2 + 3. Random/unwanted open/closing of contactors is definitely something I want to avoid. When the contactors are already open, the BMS can block future closing of the contactors. So, for example, we can end up in drive mode with only one pack enabled. In this case, if the BMS reboots, then something unintended could happen. The question is, can the pico boot up fast enough that the contactors wouldn't notice a quick off+on? Probably not. But it's worth trying/testing.
Buzzer is a great idea also. I plan to have a 'dashboard vcu' for driving the original analogue gauges and lights. Will add some sort of buzzer to this also. The dash vcu will also have a logger built in and be a hub for monitoring the overall state of the car (rather than having one wifi ap per device). So, any errors from any part of the car will be surfaced on the dash and also a web interface provided by the dash.
Christian
My 1965 Ford Mustang project
chrskly.com
My 1965 Ford Mustang project
chrskly.com
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Re: 1965 Ford Mustang
Hi Chris, how are you finding the is300H transmission? I'm wanting some assurance it can deliver motorway driving speeds comfortably without MG1 exploding but I've found no evidence as of yet and as it's early in development in the EV conversion world there isn't a wealth of knowledge from running projects.
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Re: 1965 Ford Mustang
Just for clarification, I was hoping you might be able to provide some information on the RPM from the gearbox output at different voltages.
- chrskly
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Re: 1965 Ford Mustang
Hey, sorry, I missed this somehow. To be honest my gs300 has been sitting untouched on the garage floor for months. I have lots of other work to do on the car until I get to the stage of spinning the wheels. For example, replacing rusted out floorsJacobsmess wrote: ↑Wed May 10, 2023 8:01 pm Just for clarification, I was hoping you might be able to provide some information on the RPM from the gearbox output at different voltages.
Christian
My 1965 Ford Mustang project
chrskly.com
My 1965 Ford Mustang project
chrskly.com
- PatrcioEV-ATX
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Re: 1965 Ford Mustang
Keep at it. Someday you'll have a gorgeous classic to tool around in!chrskly wrote: ↑Fri May 12, 2023 10:59 am Hey, sorry, I missed this somehow. To be honest my gs300 has been sitting untouched on the garage floor for months. I have lots of other work to do on the car until I get to the stage of spinning the wheels. For example, replacing rusted out floors
tempImagebUzNxr.gif
1998 Ford ZX2 - DC EV conversion(sold) http://evalbum.com/2093
2012 Nissan Leaf (sold)
2016 Mercedes B250e (sold)
2023 Volvo C40
Current: 1964 Rambler Classic 660 w/ GS450h set up. 36kwh Tesla batteries from B250e.
https://www.instagram.com/rambler_660e/
2012 Nissan Leaf (sold)
2016 Mercedes B250e (sold)
2023 Volvo C40
Current: 1964 Rambler Classic 660 w/ GS450h set up. 36kwh Tesla batteries from B250e.
https://www.instagram.com/rambler_660e/
- chrskly
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Re: 1965 Ford Mustang
That's the hopePatrcioEV-ATX wrote: ↑Fri May 12, 2023 1:21 pm Keep at it. Someday you'll have a gorgeous classic to tool around in!
Christian
My 1965 Ford Mustang project
chrskly.com
My 1965 Ford Mustang project
chrskly.com
- chrskly
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Re: [WIP] 1965 Ford Mustang
I broke rule #1 of ev conversion club. I chose to convert a rust bucket. The bodywork continues...
Christian
My 1965 Ford Mustang project
chrskly.com
My 1965 Ford Mustang project
chrskly.com
- rstevens81
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Re: [WIP] 1965 Ford Mustang
I would say your in good company
It's the slight problem when you choose the car you want not just something that's randomly cheap.
It's the slight problem when you choose the car you want not just something that's randomly cheap.
Rule 1 of EV Club is don't buy a rust bucket....
Which rule does everyone forget
Which rule does everyone forget
Re: [WIP] 1965 Ford Mustang
Oh wow, I't looks like it may have been easier to build a new car from scratch haha. At least you can honestly say that you've touched every single nut and bolt on the car.
Best of luck, I envy your strength of commitment.
Re: [WIP] 1965 Ford Mustang
Some people are just cursed with good taste i guess.rstevens81 wrote: ↑Mon Aug 28, 2023 7:40 pm I would say your in good company
It's the slight problem when you choose the car you want not just something that's randomly cheap.