My drive is on a steep slope, and immediately to one side is a drop of about 7 feet at the highest point.

My BMW's charging cable is 6 metres. Because of the (lack of) length of the cable, I have to reverse up the drive to charge it. I don't have a problem with that as such, but it's more hazardous than just driving forwards up it. Especially since the BMW now hauls on its brakes as soon as it detects the marker flagstone that I've put there to prevent me reversing into the garage wall by accident.

So I was thinking - a nice 15-metre cable should be long enough to charge the car if I park it facing forwards. I've found plenty of aftermarket options, but I can't get hold of the parts department at BMW to ask whether BMW themselves do one. Does anyone know whether they do a longer cable, or will a decent aftermarket one do the job just as well?

All the evse equipment I saw only goes to 25ft at most. If you can find a 15m cable let me know. That would give me additional options on installing an L2 charger

 

I've found aftermarket cables up to 50 metres, but I don't know how reliable they are.

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ETA: Just spoke to them. As a company, they seem reliable enough. They build the cables to order and can go up to 50 metres, though there's a voltage drop the longer you go. They've just quoted me about £320 for 20 metres.

 

In the US, the NEC states 25ft to be the max length, unless there's cable management or you're willing to get a custom wire made for your particular charger.

If there's room to move the charger closer, obviously, that would be the first thing to do. I've also seen neighbors mount their EVSE on a dedicated post to bring it closer/make it more convenient....it will depend on your site conditions and what tradeoff you're willing to make.

As you can see, power drops as length increases so maybe have them make you a cable that doesn't have too much slack?

 

I've put there to prevent me reversing into the garage wall by accident.

Is this an inside or outside location?

Sounds like your outlet or charger is mounted in the wrong spot. If in a garage, why get it moved to a better location. Non-flexible wire in your walls is much cheaper per meter than flexible all weather cable on the charger. If you're not handy, there is additional markup of an electrician but that still is minimal. Anything that moves can wear out, so you want the flexible cable as short as possible. Your flexible cable on your charger also is usually thinner than in your wall and has bigger voltage losses. I'd always move the charger and outlet as close to where you're going to charge as you can.

 

My drive is on a steep slope, and immediately to one side is a drop of about 7 feet at the highest point.

My BMW's charging cable is 6 metres. Because of the (lack of) length of the cable, I have to reverse up the drive to charge it. I don't have a problem with that as such, but it's more hazardous than just driving forwards up it. Especially since the BMW now hauls on its brakes as soon as it detects the marker flagstone that I've put there to prevent me reversing into the garage wall by accident.

So I was thinking - a nice 15-metre cable should be long enough to charge the car if I park it facing forwards. I've found plenty of aftermarket options, but I can't get hold of the parts department at BMW to ask whether BMW themselves do one. Does anyone know whether they do a longer cable, or will a decent aftermarket one do the job just as well?

I would move the charger to the other side. That is a more professional and better solution than a long cable which is in the way all the time, is heavy, risking driving over and damaging it, dragging on the ground all the time and even electrically wrong.

 

Also, putting back the cable on the rack is quite annoying and takes time. I have a 7.5m cable attached to my charger, but I prefer backing the car over a steep narrow slope and use 50cm of cable than removing the full 7.5m of cable and having to put it back afterwards.

 

I'm sure money is no issue, @Squirrel1974 has an i4 and a Range Rover, so she is clearly loaded

I too would suggest you think about a post mounting. You can use armoured cable for the installation and you can then bury the cable to the charger if you want to make it neater. Unless you are planning on moving, it's a long term investment as EVs are here to stay.

 

For the "hauls on it's brakes" issue, I believe you can bypass that when reversing. I need to back carefully into a tight garage and found the auto brake too conservative. Of course, then it's between you and the rock.

 

Is this an inside or outside location?

It's outside. The charger is mounted on a side wall outdoors, there is no other option because the garage door is in the way.

I would move the charger to the other side. That is a more professional and better solution than a long cable which is in the way all the time, is heavy, risking driving over and damaging it, dragging on the ground all the time and even electrically wrong.

Can't. There is no other side. The front door is on the left, flush with the garage door, then there's the garage itself, then the side wall of the building. The charger is mounted at the front of the side wall on the outside of the garage.

I'm sure money is no issue, @Squirrel1974 has an i4 and a Range Rover, so she is clearly loaded

I too would suggest you think about a post mounting. You can use armoured cable for the installation and you can then bury the cable to the charger if you want to make it neater. Unless you are planning on moving, it's a long term investment as EVs are here to stay.

Was loaded. I kept buying cars. 😁 One costs me an arm and a leg to keep in secure storage these days!

Nope, post mounting wouldn't work either. The configuration of the drive means that the only logical place for a post would be next to the boundary with next door, towards the bottom of the drive. The neighbours wouldn't be able to drive into it because their drive is level while mine is on a slope, but I wouldn't put it past them to use it to lean stuff on or tap it with a van's wing mirror or something. Besides which, it would look weird.

It's all fine, I've got a 10m cable arriving tomorrow now. I'll fit it and show you the results if you want to see. 10m isn't so bad.

 

My home charge point has a 10m cable on it (maximum offered by Hypervolt) and works just fine. It means I can in theory charge the M50 in three places depending upon what other members of the ‘fleet’ have been parked where.

 

Why is 22kW less loss than 7kW, and 11kW less loss than 3.7kW? Are the colors just labelled wrong? [Or do the 22 and 11kW use a higher voltage, and hence less relative loss?]

Sorry, just a nit.

I agree, I would say avoid getting too long of a cable. I have a 25ft (~8m) one in my garage and I wouldn't want it any longer, it gets a little unwieldy, and I'd worry about the reliabilty outside. That said, I wouldn't worry too much about the loss. If you believe the red curve, you're losing about 70W @ 7kW, only about 1%, a good deal less than the "charging losses" in the electronics/battery path...

 

Why is 22kW less loss than 7kW, and 11kW less loss than 3.7kW? Are the colors just labelled wrong? [Or do the 22 and 11kW use a higher voltage, and hence less relative loss?]

If you click the link, they are different models. So nothing is constant. You are right if they were all the exact same wire, voltage, and phase, higher power would equal more loss. But here 22kW uses 3 phase (more condutors and more phases) vs 7kw single phase.