I'm due to take delivery of my S85 in Dec, however reading these forums I'm actually a bit confused about charging rates, primarily on Ecotricty network of fast chargers.
Why when we plug into the 43kw 63amp side do we only receive 11kw ? ( I only ordered a single charger)
Yes, if you have a single charger. The charger is the limiting factor here.
My my friend has a leaf and regularly uses the other side, 50kw 125amps I think, and I realise his battery is a third the size of ours, but I believed that if I plugged into 43kw 63 amps I would get just under half his rate of charge, however as my batteries are three times bigger I expected the rate to stay high for six times ( 3x bigger batteries, half speed) longer before reducing down.
If you had the (not yet available) CHAdeMO adapter you could plug in to the other side and charge at the same initial speed as the Leaf, and indeed you would stay at full speed much longer than the Leaf before reducing down, due to the bigger battery.
But reducing down isn't the issue here. No Model S can draw the full 43kW from the AC side, because it doesn't have a sufficiently large on-board charger. A dual-charger Model S can draw 22kW, single charger 11kW.
This is the big difference between AC charging and DC charging. With AC charging, the charger is in the car, and you are limited by that. With DC charging (CHAdeMO, SuperCharger etc.), the charger is in the charging station. "reducing down" can in theory occur in either case - but in practice, AC charging is sufficiently slow in the first place that it doesn't need to reduce down in normal circumstances.
But users are saying I will get 11kw. What sort of miles in an hour will this give to a low battery please if correct.
A shade over 30. Dual chargers would give you double that.
At home I'm getting a 32amp charger, will this be 6.6 kW? Ie half again the speed of the above 11kw?
If it's really 32amp, that's 32*230 = 7.36kW. If it's a Chargemaster unit, they are 30A, so 6.9kW (assuming typical mains voltage - if your voltage happens to be higher/lower than average, you do correspondingly better/worse). So about 20mph.
In practice, that's plenty for overnight charging: although it's notionally about 12 hours for a full charge, unless you have a very unusual lifestyle you will rarely come home having run the car down to exactly zero, eat/sleep for less than 12 hours, and depart again on a day where you need a full charge.
Where it is less adequate is for fast-turnaround - perhaps you've been driving on business during the day, come home, and want to depart for a weekend away with a full charge. Standard home chargepoint won't achieve that. Also an issue is if you want to keep the car at (say) 80% charge and quickly top up to a 100% charge when you unexpectedly want to make a long trip (especially in winter when you will be pre-heating the car at the same time and the heating takes most of that 7kW).
However, unless you happen to have a 3-phase supply at home, 7kW is the best you are going to get, and for most people it's OK.
