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Extending the Granny cable

Kithmo

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Just a thought, I know we can use a 13A rated extension cable when we charge with the granny, but I was wondering if we could plug the type 2 charging cable into the granny cable to extend it to the car.
So I'm thinking, 13A socket - 13A 10m extension - Granny charger - type 2 cable - car.
Is this feasible or is it a bit dodgy ?
 
Thanks.
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Just a thought, I know we can use a 13A rated extension cable when we charge with the granny, but I was wondering if we could plug the type 2 charging cable into the granny cable to extend it to the car.
So I'm thinking, 13A socket - 13A 10m extension - Granny charger - type 2 cable - car.
Is this feasible or is it a bit dodgy ?
13 amp socket plug in 13 amp extension cable to 13 amp socket, plug in 13 amp plug on granny lead, plug in other end to car type 2.
I have done it, only charges at 3 amps
 
Isn’t it Watts / volts ? 2.4 Kw (2400 W) / 240 volts = 10 Amps current.through the cable.
 
Well the charge time (from empty) of 18 hours corresponds to 3kW constant charge. The granny charger is quite small for a 3kW charger but I suppose it is possible.
 
I remember watching the Ozzy / German guy on Unplugged EV...a famous PHEV blogger . For an exercise, he plugged in every single extension lead he had, together....which was a lot... To see if it still charged his car up OK. It did!
The PHEV and MG granny chargers are very similar. (I still use both regularly)
 
I have thought about cutting the cable and extending it with a junction box as the 13a lead is ridiculously short. Have yet to establish cable spec and of course it would invalidate any warranty on the charger.
 
You'd be much better off using a standard extension cable - that way you would not affect your warranty. If you have cut the charger wire you would certainly not get a free replacement if the charger failed. If you need to leave it out in the rain you can put the plug/socket into a plastic bag and seal it up.
 
I agree with what's been said. The charger must be "rainproof", At least, mine has dangled from a water proof outside socket in the rain, on numerous occasions.

A waterproof extension lead would be my choice.
 
This is the one I purchased.


We only have this option of charging at home and it's been fine so far. The car is rarely below 20miles full so we can full it to 100miles overnight. If we need a quicker charge there are street chargers every few hundred yards in London.
 
As has been said, the "granny" charger runs at 10A, which is about 2.4kW at the appox. 235v UK mains voltage. This equates to about 7.5 - 8 miles per hour charging rate (this is what I've measured on our car whilst we've been on holiday, using the granny charger every night). If you use a long extension lead, you'll drop a few volts across the lead, so reducing the charging power a small amount (maybe 5% or so). Therefore the rule of thumb is to use as short an extension as possible, but it's safe to use any mains extension rated for 13A, provided it's fully unwouned (if it's a reel type) and laid in free air. Bear in mind that although 10A may be well under the max. lead rating of 13A, the charger will be drawing this current continuously for several hours, so the extension lead will warm up. Therefore use the best quality extension you can find (with the thickest cable)... some cheap ones are rated at 13A, but use inferior cable and will warm up more, and drop more volts across the cable.
 
Just as a matter of interest, is there any difference in charging efficiency between the granny and a 7 kWh home charger ?
 
No it’s still provides the same amount of charge, but just at a slower rate, but you could argue is better for the batteries.
 
Both the 2.4kW "granny" and 7kw "fast" home charger are regarded as battery friendly... even at 7kW the battery is charging slowly enough to be gentle on the chemistry. It's only when you're looking at charging from empty to full in under a couple of hours that the battery chemistry sees significant "wear" (ie with a RAPID charger at 50kW or more).
 
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