Tuesday, 3 September 2013

Last week before the Brighton Mini Maker Fair!

Ok, it's the big push.

Met Steve at SMD (the mechanics) on Friday 30th to get a lesson in how to wire a 220V EV battery without killing yourself.

Unfortunately the neoprene tape I had ordered was taking a little longer to arrive than I had expected and was not there on Friday so we used Gaffer tape and some foam tape I had as a temporary replacement and I wired a box (1 of 3) with Steve looking on to make sure I knew what I was doing, Steve suggested a good idea of using elastic bands to separate the banks from each other and the positives in each bank from the negatives in each bank, this way it is much easier to follow what you are doing closely double checking each and every connection you make (one wrong positive from a different bank and BANG say goodbye to a finger potentially, wiring a LIPO battery is not for the faint of heart)

Anyway after a lot of talking with Steve on how to wire the car, towed it home from the mechanics back to mine a 5 min journey, with Steve at the wheel (thanks again Steve) and by Friday at around 4:30PM the car was at my home ready for the final stage wiring!

Saturday 31st Aug

Neoprene arrived this morning so I was able to get straight down to wiring up the batteries proper, I had two wiring layout  options I went for the slightly more complicated to wire up method which would give a better end layout of the buss bars in the top of the boxes, following Steve’s advice as how to wire them (slowly checking every connection from each banded bundle wiring only 1 buss bar at a time and then insulating it completely with the wide neoprene self-adhesive tape before moving on to the next one.

Once I had done all the buss bars I moved onto the LVC/HVC cut-off boards Steve had forgotten to bring the HVC/LVC extender boards, so I picked them up on Sunday, Thanks again Steve for being available at weekends.

I also picked up a HV fuse and contactor set from Steve, Forgot to pick up the magnets for the throttle position sensor (TPS) however, my ever loving partner picked these up yesterday (Monday 2nd) as she is as keen as I to see this baby on the road.

On Saturday I ran most of the HV cables into the car and cut them to length, on Steve’s advice I cut 200mm tails from these measured cables to make the terminal connections for the battery packs, this is to avoid the need to take the lids off the battery boxes in the car in order to get them in and out of the car, obvious really.

Crimped up the terminal tails and connected them to the buss bars in the battery boxes, finished the last box on Monday evening, insulated the inside of the batt box lids and screwed all 3 lids in place.
So by Monday evening I had finished the batteries, fitted in most of the HV cable (bar the small bits that wire the motor into Series field mode) wired in the 12V battery connection from the new Lifepo 12V battery block, Damn it’s light not sure if I can charge this from a standard 12 car battery charger I guess not as it would probably damage the battery.

Wired the Live & Neutral connections (these connect to the battery side of the Soliton Jr) for the DC-DC convertor that will take the place of the alternator and keep the 12V battery charged when the car is in use, this prevent voltage drop when you switch on lights heaters or use the electric windows for example (I am actually using a cheap power supply as a DC-DC convertor as genuine DC-DC convertors are very expensive, According to Steve he has had several arguments with people over this one and although others have said this will not/cannot work, it does!) essentially you are just using it as a voltage step-down transformer

Wired the +ve out from the PSU/DC-DC convertor, Wired the signal grounds for the Soliton Jr, Crimped up most of the HV cables (bar the front battery box as the light was fading by then)
Which just leaves :-

1) Wire throttle position sensor

2) Wire the vacuum pump sensor/switch

3) Fit two rear batt boxes (will be testing with just the two rear boxes giving 148V)

4) Fit fuse between two rear batt boxes, I am told by Steve that a fuse is better placed in the middle of a pack to minimize the potential difference at any one point (to 74V in this case which is “fairly” safe)

5) Fit HV contactor, Just ground and ignition wires I think, This is the big relay that switches on the battery pack when I turn the key

6) Wire the motor in Series field mode, the motor has 6 big pins, connect them one way for series field mode the other for parallel field mode, details on the spec sheet from Kostov.

7) Find an ignition signal in the rear of the car for connection to Soliton Jr, charger, contactor etc.

I am sure there is loads more that I have forgotten, but gotta go now and get to it.

1 comment:

  1. I was a bit lost when I found out there was no Brighton Mini Maker Faire this year so I decided to have one.


    Its free to exhibit we would love to have you there :-)