Speak EV - Electric Car Forums banner

1 - 20 of 33 Posts

·
Registered
Joined
·
89 Posts
Discussion Starter #1
OK, so first things first - there is NO intention to use two leads to charge a car/cars at the same time.

My charger is in the garage and has a tethered 5m lead. In winter that's fine, as the car is always put back in the garage every night. In the better weather, sometimes I'll be using the garage space as a workshop and the car can't go in at night. Problem is that the 5m lead's not really long enough to reach the car unless parked in an awkward position in front of the garage - blocking access for other vehicles - and I can't close or lock the garage door with the charging lead sticking out.

My ideal solution would be to but a second, longer, tethered cable and run it through a hole in the garage wall to the charger inside, and fit a plug holster on the wall outside with some hooks to coil the cable around when not in use. I could then plug the car (Ampera - 16A charge only) either inside or outside of the garage.

I'm happy to hack the charger and competent with the internal wiring, but read somewhere about a resistor in the cable to determine charge level, and wondered if having two leads connected might confuse the unit or car.

Any tech types on this forum who know if that's at all possible?

Thanks
 

·
Premium Member
Joined
·
11,588 Posts
So you want to have a 2nd lead connected to the mains with live pins, on an unshuttered plug not connected to a car? Do you realise how dangerous that could be :eek:

The easy, safe solution is to change to a socket charger and have two Type 2 to Type 1 leads (often cheap on here second hand). You would then plug either the short (inside) or long (outside) lead in.

With respect to OP, just how long will it be until someone in UK is killed by some car charging DIY?
 
  • Like
Reactions: Matt Beard

·
Registered
Joined
·
89 Posts
Discussion Starter #4
You can get 10m leads online, would that be of use?

For instance

16 Amp Car Charger Plug and Lead For The Nissan Leaf
That would sort out the cable length issue, if I was to change the current 5m one to a 10m one, but still not the problem of not being able to close or lock the garage door with the (longer) cable sticking out. My options seem to be either two leads (as I have suggested could be possible), a second charger unit fitted outside the garage, or use the granny charger plugged into an existing 13A outside socket when I can't put the car in the garage. But thanks for the recommendation.
 

·
Super Moderator
Joined
·
7,695 Posts
OK, so first things first - there is NO intention to use two leads to charge a car/cars at the same time.

My charger is in the garage and has a tethered 5m lead. In winter that's fine, as the car is always put back in the garage every night. In the better weather, sometimes I'll be using the garage space as a workshop and the car can't go in at night. Problem is that the 5m lead's not really long enough to reach the car unless parked in an awkward position in front of the garage - blocking access for other vehicles - and I can't close or lock the garage door with the charging lead sticking out.

My ideal solution would be to but a second, longer, tethered cable and run it through a hole in the garage wall to the charger inside, and fit a plug holster on the wall outside with some hooks to coil the cable around when not in use. I could then plug the car (Ampera - 16A charge only) either inside or outside of the garage.

I'm happy to hack the charger and competent with the internal wiring, but read somewhere about a resistor in the cable to determine charge level, and wondered if having two leads connected might confuse the unit or car.

Any tech types on this forum who know if that's at all possible?

Thanks
Best case, you use the two wire set up totally successfully for a few decades and are saved from the very minor inconvenience of occasionally plugging in the granny lead.

Worst case, a visiting friend or relative plugs in without asking (or asks your partner or child instead of you) while your car is also plugged in in the garage. You both have economy seven timers set and the cars start charging at the same time in the middle of the night. Your electrical box sets on fire and your house burns down with you and your family inside.
 

·
Registered
Joined
·
1,956 Posts
Yes, it can be done. It can even be done safely, but the only way to do it properly is effectively to have a double-headed chargepoint, which gets a feed from your existing chargepoint. The cost will probably be more expensive than just buying another chargepoint.

J1772 Hydra
 

·
Registered
Joined
·
89 Posts
Discussion Starter #9
Worst case, ...... Your electrical box sets on fire and your house burns down with you and your family inside.
A bit unlikely TBH as the charging unit is protected by a 16A MCB and I suspect that the unit itself probably has some internal protection too - and in the unlikely event that two cars were accidentally connected, I'm more concerned how the car(s) would react, rather than if an inferno might ensue!
 

·
Super Moderator
Joined
·
7,695 Posts
A bit unlikely TBH as the charging unit is protected by a 16A MCB and I suspect that the unit itself probably has some internal protection too - and in the unlikely event that two cars were accidentally connected, I'm more concerned how the car(s) would react, rather than if an inferno might ensue!
If I understand the spec right both cars would simply do as they like in the knowledge that 16A is available to use. I don’t think a 16A MCB will trip all that quickly at 32A, and who knows which part of the setup will get hot the quickest.

Of course it’s also quite possible one or both cars will be damaged too, which could mean anything from a big bill to a fire. Why mess about with this stuff?
 

·
Registered
Joined
·
89 Posts
Discussion Starter #11
Yes, it can be done. It can even be done safely, but the only way to do it properly is effectively to have a double-headed chargepoint, which gets a feed from your existing chargepoint. The cost will probably be more expensive than just buying another chargepoint.

J1772 Hydra
That's an interesting little project, but my charger is only 16A and the Hydra was designed (as far as I read) to split a 32A (7Kw) unit to provide charging for two vehicles at 3.3Kw.

As the cost of a tethered lead on its own is not significantly more than an older used 16A 3.3Kw charger, I might just end up buying and fitting a second (pre-owned) unit on the outside of the garage.
 

·
Registered
Joined
·
89 Posts
Discussion Starter #13

·
Premium Member
Joined
·
11,588 Posts
  • Like
Reactions: Matt Beard

·
Registered
Joined
·
1,956 Posts
OK, that 4 pole version could work to switch between two tethered leads - one inside and one outside. Thanks for that - it wasn't something that I'd considered.
If you're thinking of having a changeover switch, you don't need a meaty 20 amp changeover switch. You just need to switch the low-voltage pilot signal so that it can't possibly be active on both outputs at once. No pilot signal return detected, the contactor won't energise.
 

·
Registered
Joined
·
5,443 Posts
I don’t think a 16A MCB will trip all that quickly at 32A
Typically between 20 and 90 seconds.

If you're thinking of having a changeover switch, you don't need a meaty 20 amp changeover switch. You just need to switch the low-voltage pilot signal so that it can't possibly be active on both outputs at once. No pilot signal return detected, the contactor won't energise.
It's extremely important to switch the power pins otherwise both connectors are live during charging.

It's not exactly an elegant solution but assuming you wire this competently it's hard to see that much can go wrong.

Equally just cutting a notch in your garage door so that the cable can escape even when it's closed does seem much simpler.
 

·
Registered
Joined
·
629 Posts
No pilot signal return detected, the contactor won't energise.
But both leads will go live if one is activated tho. Which defeats the main reason for the interlock, that power is not put on the lead until it is connected to the car.

Which is also I suspect why 2 cars could not be charged simultaneously. The second car to be connected would see the cable is already live before the power is asked for and report that as a fault.
 

·
Registered
Joined
·
89 Posts
Discussion Starter #20
I have an 8mtr lead on my charger which is inside the garage, a small notch allows the cable to be used outside, often the simplest solutions work just fine.
That was always my original plan, but I was kind of hoping for something a bit more elegant. The "notch" is quite do-able, so as other options seem not to be ideal, or expensive, or both, that (or the cat-flap!) might end up being the end decision.
 
1 - 20 of 33 Posts
Top