Z3 EV Conversion
- Thread starter Andybpowell
- Start date
Ooft. Bet that was a great big grin though!So good news bad news time
The good news is that I've been out and about driving really smooth awesome power delivery, had a big silly grin on my face
Bad news, I took it for a spin yesterday lunchtime after a bit more Tweaking got half way round the block and the power just nose dived
managed to nurse it homeand looked at the bms data and the voltage on some of the battery cells was really low so after stripping it down which was really hard while in the car it seems 2 cells in one module are bad to be honest after checking every cell I'm not too impressed with the whole pack and that was after about 10 miles so I'm going to swap it out for my other pack and hopefully get better results
Yes one big cheesy grin
no idea on performance yet but It feels good so smooth and the noise is great excellent whine almost supercharger ish (I have removed all of the sound deadening under the bonnet)
Since I had to strip out the battery pack I decided to do some upgrades to make the wiring simpler make it easier to install the second battery pack and improve reliability, I've gone over to canbus completly for all of my control boards the original used individual wires for the control signals inline with Tom De Bree's original bms design my new design communicates solely via canbus also I have done away with my contactor control board and
moved the power stage for the contactors over to the bms board but with processing still on my main board and let me tell you it was a pain in the arse well actually a pain in the neck and my brain feels like jelly as I was rewriting Three seperate bits of software at the same time so I didn't lose track of what I was doing good job I have lots of monitors
The battery pack is pretty much back together had to make up some keys to get the modules out
something I hadn't expected to do while it was in the car, just need to redo the wiring inline with my new design and it should be back on the road
I also discovered why one module went down, it seems that I mixed up the modules and that one was from the other pack which was not as fully charged and so was pulled down below min voltage while the rest of the pack was still fine
moved the power stage for the contactors over to the bms board but with processing still on my main board and let me tell you it was a pain in the arse well actually a pain in the neck and my brain feels like jelly as I was rewriting Three seperate bits of software at the same time so I didn't lose track of what I was doing good job I have lots of monitors
The battery pack is pretty much back together had to make up some keys to get the modules out
something I hadn't expected to do while it was in the car, just need to redo the wiring inline with my new design and it should be back on the road
I also discovered why one module went down, it seems that I mixed up the modules and that one was from the other pack which was not as fully charged and so was pulled down below min voltage while the rest of the pack was still fine
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Ok so I might have got a bit carried away with what started out with a few mods and ended up with me redesigning all of the control boards
originally I had
Two BMS (battery managment system) boards one for each battery pack
One contactor controller board
One to control the power to all of the devices and control charging
And the main controller which connected to 3 seperate canbus's, interfaced with the inverter with the car controls and many other things you don't really think about like turning on the reverse light now you don't use the gearbox
Now I have the two bms boards and one main board which does everything else it's not quite finished yet I still have to add a few resistors and capacitors and the canbus interfaces but nearly done. I had to design it as a main board with a piggyback as the free design software I use limits board size but this worked out really well, I also included an interface for a 4 1/2" touchscreen display which will be mounted somewhere in the car just need to turn my brain into jelly again doing the coding (I've got a headache just thinking about it)
originally I had
Two BMS (battery managment system) boards one for each battery pack
One contactor controller board
One to control the power to all of the devices and control charging
And the main controller which connected to 3 seperate canbus's, interfaced with the inverter with the car controls and many other things you don't really think about like turning on the reverse light now you don't use the gearbox
Now I have the two bms boards and one main board which does everything else it's not quite finished yet I still have to add a few resistors and capacitors and the canbus interfaces but nearly done. I had to design it as a main board with a piggyback as the free design software I use limits board size but this worked out really well, I also included an interface for a 4 1/2" touchscreen display which will be mounted somewhere in the car just need to turn my brain into jelly again doing the coding (I've got a headache just thinking about it)
I shall try to keep you enthralledAwesome thread! Look forward to seeing more on this
Ok my brain is now oficially jelly but the programming is hopefully done and since the weather is miserable and I have to work on the Z3 outside in the rain I decided to make a start on programming the touch screen display so that I can have some meaningful data on what is happening whilst in the car without having a laptop plugged in as much as I have connected most of the instrument cluster the information it provides is not enough for an EV especially a converted EV so far it's going well the editor for the display is pretty flexible and allows you to create an asthetically pleasing interface if your graphical talents allow not really my thing but I try
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So it's been a bit quiet for the last few weeks mainly due to the weather I need to do some work on the battery pack and having to work outside on an EV conversion with nearly 400 Volts under the bonnet is not ideal and if I take it out and put it in the garage it will prevent access into my garden which I can't do so I'm considering either getting a small one of these to work under
or putting the project on hold until the weather improves
or putting the project on hold until the weather improves
Attachments
I need a big one of these...and somewhere to put it. The latter part is trickier!
I'm in the same boat space is the issue
If I had the space I'd just build a big garage
Had something of a disaster yesterday while adjusting some setings on the inverter managed to blow a 350 Amp fuse and at the very least cooked my Teensy 4 controller worst case is if the inverter is fried as well should know in the next few day's if it will stop raining
Oh crap! Was that straight power draw?Had something of a disaster yesterday while adjusting some setings on the inverter managed to blow a 350 Amp fuse and at the very least cooked my Teensy 4 controller worst case is if the inverter is fried as well should know in the next few day's if it will stop raining
Yes I'm truly special (in a window licking way)
if I have killed the inverter then I'm going up to 110 or 160Kw might as well make the best of a bad thing
Really great thread and very impressed with the work. Some lovely toys to play with, cnc machine etc.
Look forward to updates and wish you luck.
Look forward to updates and wish you luck.
Thanks it means a lot especially when things are going wrong and you wonder why you started such a project
So further to my somewhat self inflicted disaster the other week I've had to remove the battery box to carry out repairs
So far I know that I have blown a 350 Amp fuse killed my Teensy 4.0 Microcontroller and fused one main contactor tha last of these is a bit of a pain because I didn't allow for changing the contactor in-situ (my poor design) so I have had to make up new lifting gear to allow me to remove the battery box without removing the front end as it happens this is also much more stable than my original design
so now it's out I can replace the dead components, test the pack, perform a few upgrades and get it refitted so that I can test the motor and Inverter I really hope I havent killed the inverter depending on how the testing goes I might get it back in before the snow hits
So far I know that I have blown a 350 Amp fuse killed my Teensy 4.0 Microcontroller and fused one main contactor tha last of these is a bit of a pain because I didn't allow for changing the contactor in-situ (my poor design) so I have had to make up new lifting gear to allow me to remove the battery box without removing the front end as it happens this is also much more stable than my original design
so now it's out I can replace the dead components, test the pack, perform a few upgrades and get it refitted so that I can test the motor and Inverter I really hope I havent killed the inverter depending on how the testing goes I might get it back in before the snow hits
More bad news I got the battery pack all repaired and back in and I've definatly cooked the inverter and possibly the aftermarket control board not really what I wanted to find
You've gotta laugh or you'd cry
You've gotta laugh or you'd cry
Sorry to hear that Andy. Keep going, you'll get there mate.