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was wondering if anyone has thought just how much it is to charge at home, by that i mean is the input to the charger constant or does it decrease as the car becomes more fully charged?

oldies like me remember when you had lead acid batteries (12v) on I.C.E. cars, the ammeter dropped as the battery became fully charged so the input from the supply (240v) reduced, so the units used were less.

can you follow this?

don't know about lithium batteries, but the same may apply.

anyone any thoughts on this?
 

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I have a Smart meter. On my 24kWh Leaf, it seems to follow what Aceshigh says. It starts off at what I expect is constant current (ie current limited), then rolls off across the final hour. Nissan talk of battery balancing in the final hour. I am sure they are right when you consider the challenges of a massively parallel battery. A gentle landing on terminal voltage is probably a good idea!

Battery University say that you can over-voltage charge Li-io but when you get near capacity, you have to drop the voltage as over-charging is the main cause of capacity degradation (causes plating of the lithium). Guess this is why computers limit their charge to 80% of capacity as they age and Nissan offer a battery saver mode which limits charge to 80%.

The other main killer is heat. The Leaf (and I am sure this is true of other manufacturers) monitor the battery temperature and limit charge/discharge with temperature.

Hope that helps
 

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This is battery precondition at 6am and 8am followed by cabin heating for an 8:40 departure.

There's about a 50% charge starting about 1pm showing the tapering off.
 
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