Took a couple of weeks off with the family after getting the Audi rolling. Staycation in the west of Ireland where rain, mist and wind was the order of the day
It gave me plenty of time to plan and think about the next big step. Full Leaf pack install.
First off, the front battery box to hold 20 of the 48 modules - 24 go where the petrol tank used to be and the remaining 4, to the left of the engine bay in a separate battery box. Time to hone those stick welding skills! My brother has a Mig next door but the running back and forth to his workshop was slowing things down so I sped things up by using the stick. Back to basics. Took a little time but I made most of the mess on the cross member that ran left to right between the chassis rails to catch the rear of the battery box. Pretty happy with the results. I measured the 30x30x3mm angle built box to take into account the threaded bar nuts at either end of the 20 cell 'brick' as well as some EVA foam mat I had got my hands on to remove some innaccuracies in the fit when the battery was dropped in. When time came for the test fit of the cage, I found it was a touch too high so I dropped the cross member by 20mm with a few amendments and all was right.
Time to put it together. I had thought of a number of different ways to build the box (local fabricators were out the door busy so went the DIY route) and found one guy in the US who had gone the same route when faced with zero alu welding skills - build the frame and bond in the aluminium walls to create a sealed tub. As you can see, I cut back the angle on the top section to allow the whole brick to be dropped in in one go so they could be all tightened up to the original tolerances, preventing swelling during operation. For the 20 cells, those added up to 680mm end to end. Iwas able to cross check against the 24 pack I still had fully assembled. In the end, I found that once you tighted the threaded bar up, there is a point where you just cannot go any further as the cell chassis bolt holes meet, creating the perfect distance. Perfect fit!... yeah... more on that later
In the mean time, as I was waiting for the bonding to work its magic (spoiler alert - the magic sucked!) I decided it was the better time as any to strip out ALL the metal work, clean it down, prime it and give it a good dose of hardcore black!
So worth the effort. When it all went back in, it looks the business... I swear, it looks OEM.... mwahahaha!... ah... that's a good one... ahhh. *sniff*. Well... If it weren't for the mouldy welding and you had bottle ends for glasses, it might have looked OEM
Still. I was happy that at least for a while, rust was surpressed.
Again, while things dried, It was time for the cooling system. For this, I ditched the Leaf circulation pump as I didn't want to start the whole rigmarole of dealing with PWM and wanted a blunt tool for the job. In step, the Bosch A0018353564 used mainly in the Mercedes Vito vans and ML series but also across VAG and Ford so, readily available for €20 on ebay and seems to be a weapon of choice as a result. The radiator, as cooling is not going to be that much of an issue and my second vice is motorcycles, came from a Honda CBF1000. It had the same hose size as the Leaf ports and was a perfect little unit for those blistering summer days we get on the sunny south east of Ireland
I used all the hoses and clamps I salvaged from 2 broken Leafs for next to nothing on visits to scrap yards for other bits. I got a number of different sized Tee's to take into account the Audi coolant tank. In essence, the flow come from the motor - to the pump - leave pump into a Tee (3rd branch to overflow of coolant tank) - main feeds to top of rad - out the bottom of rad- to another Tee (3rd branch from bottom of coolant tank - back up and into the heater matrix - out of matrix - into inverter - out of inverter - into motor. I had various plans to put in a split system for winter/summer (using a BMW/RangeRover solenoid) but ended up sticking with this for now. I may delete the matrix part altogether as from what I have seen, I will get bugger all heat from the motor/inveter when I need it to demist. I have seen Damien is planning to release something that he put into the Deranged Rover so, I'll keep an eye on that for cabin heating. It's either that or swap the matrix for the Mk5 Golf heater element.
https://www.ebay.co.uk/itm/SKODA-Octavi ... SwElNe2iZc. Again... I'll wear gloves and hat and thermals this winter... and keep the windows open to clear the windows
So anyway, back to the battery... yes it fitted and I was well chuffed... something wasn't right though. I had not put on the end plates used in the normal Leaf pack that prevents battery swell and already the modules at either end had a noticeable... bulge. Balls... There just wasn't room! Or was there... I took the box out for the 4th time (don't ask). BY this time I had found a novel way of taking the 'brick' in and out of the box. Turn it on its head, yes.. protecting the terminals with foam. Anyway, with a lot of coaxing, I managed to get the end plates on and getting it to fit using the slimest of fasterners I could dig out. The results were 1mm each end I would say. Toight!
It was about this time I found out the crap 'solution' I had for bonding the alu pannels in was just that. I took the opportunity and stripped it all apart again! THis time, it all went back together with proper panel bonding material... Job done. Battery brick in, crane in for the 20th time (which by now is a piece of piss) and that is not coming out again
Time then for battery-box-mini. This I did in the last couple of days using just good old aluminium plate, rivets, my no favourite bonding goo and left over Leaf pack plate to make up the mounting brackets to hold it in place in the left hand side of the engine bay. Since this pic was taken, I have actually cut and extended the terminal end to make more room for the pos and neg glands for easier access, less stress on the battery terminals and overall... just less stress
WHile all this was going on, I also tackled the new layout of the busbars and Leaf BMS wiring. Took a couple of nights and a lot of looking at it... for long periods of time.... before I figured out how to break apart the old arrangement into one that I wanted, similar to the likes of Shane did on the Porsche and Johannes in the Touran. I ordered some new male and female connectors to allow hooking it up to the rear back and got a lot of multicore from an old scrapped CNC machine to run front to back
Things still outstanding?
DC-DC. Really need to get on this. I pulled out the Panasonic unit from the Leaf and I know there is a way to get it running. There is a video from EVTV floating around where they got it working a long time back. Otherwise, suggestions?
Charging. I have a Chademo and a Type 2 port to play with. First plan was to go for the Tesla Gen 2 with EVBMW v5 board but cant afford that right now but will be on the list including the CCS adapter kit and controller over on the other Tesla Gen 2 charger thread. I am keeping a close eye on the great work Isaac and Damien are doing on getting the Chademo controller working and am planning on getting a 2nd Leaf VCU to help with testing.
Thats' it for now. Hope to get started on the rear pack next week then we are good to go for a spin again
