I was due to pick up Antoine and his brother from EDI last night and they were to stay in a local B&B and drive the car home over Saturday and Sunday.
As the car hadn’t turned a wheel for nearly 4 weeks, I decided to take out the battery and charge it as it was almost flat –not enough juice to start the car left.
With a million things running through my mind last night I went to reconnect the battery and fire up the elise. I wrestled to fit the battery into the tray, connected the +ve first and when I went to connect the negative, I got a very small spark but noticed the terminal didn’t quite fit …. I knew immediately

I had put the battery back in 180° the wrong way round. I had reversed the terminals. I was also aware from reading forums previously that this would very likely have fried the ECU.
At that point the pit of my stomach hit the floor. I couldn’t believe it. Could I have gotten away with it? I quickly swapped the battery around, jumped into the seat, unarmed the alarm. All looked good, dash lit up as normal, fuel pump primed and the car turned over when I turned the key. Alas it will not fire. The damage had indeed been done.
By this time it was about 7pm and Antoine was due to be on a plane at about 9pm. I quickly phoned him – luckily I had the foresight to get his contact no - as I had not yet spoken to him. His brother answered. They were already at the airport having gotten the train there. To begin with he didn’t understand what I was telling him. Neither him nor I could believe it. It was important that I reached them before they headed for Scotland.
I started searching SE and SELOC for similar instances and they all came up the same - 99% chance of fried ECU and possible other damage. In vain I check some fuses next to the ECU but unfortunately they were all OK.
Antoine didn’t respond to last night’s text or email or even this morning’s email. I assumed that he thought that I had done the dirty to him and sold it to someone else. He would clearly be very disappointed as this was to be his first Lotus. Thankfully he came back to me tonight, obviously gutted but understanding.
This morning I spoke to Danny McKenzie a local Auto Electrician who was recommended on here. He was very friendly however he had hurt his back and was laid up not having worked this week.
I will speak to MMC on Monday although I am not sure how I will get the car there. I need this sorted fairly quickly as Antoine is still hoping to buy the car and my insurance expires on 26th November.
My 2 second mistake is going to cost me a shed load of cash as I will need to drop the price to cover Antoine’s out of pocket expenses and the repair to the car. Looking at the forums, 111S ECUs can be on back order at Lotus and a quick PM to Junks on SELOC reveals that he doesn’t have one. I am open to any suggestions on where to find a used one. It must be an 111S Lotus K4 160 unit (part no. A117M0109F ) which is different to the 120bhp elise unit.
I will post a separate thread on Technical in case anyone has any useful advice. Robin has kindly provided some assistance via PM, so big thanks to him.
So if you have gotten this far down, please take care and don’t be a knob like me – it is looking oh so very expensive. It also highlights the risks with dealing with a foreign buyer – yes they may be willing to pay slightly more, but if something should go wrong there can be quite a bit more expense involved.
Also, always remove the –ve terminal first and when reconnecting, put it on last. If you have easy access to the terminals, the battery is the wrong way round! Just remember, nothing is easy to access on a Lotus!
Thanks for “listening”, I’m now away for a stiff drink!
Stewart