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Discussion Starter · #1 ·
I've had a Leaf for over a year and love it. As part of the initial deal with Nissan, they installed a 3kw home charging unit, which I use overnight about twice a week. I would have gone for a 6kw charger if I'd known more about chargers then, but Podpoint now want over £700 to upgrade, so I said get lost, in a polite way!
If I simply used my 3 pin charging cable in a socket in my house (through a window), would it cost me less in electricity? I appreciate that it maybe wouldn't charge as quick, (or would it?), but I charge overnight anyway, so speed and time isn't an issue, I'd just like to cut down on charging costs.
 

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Discussion Starter · #3 ·
Thanks. Yes, that makes sense.
Is there a way of finding out how much electricity I am using through my home charge point? I thought my electricity provider would know how much is being used by the HomePod specifically, but they said they can’t.
 

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If your Podpoint is connected to WiFi you can see your usage stats in the phone app and/or ask them to send you a monthly usage summary by Email.
 

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There is an overhead in charging an electric car, which is typically a few hundred Watts. So charging more slowly via a granny cable will cost slightly more than charging faster for the same amount of battery kWhs as you're charging (and using the overhead) for longer.
 
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I've had a Leaf for over a year and love it. As part of the initial deal with Nissan, they installed a 3kw home charging unit, which I use overnight about twice a week. I would have gone for a 6kw charger if I'd known more about chargers then, but Podpoint now want over £700 to upgrade, so I said get lost, in a polite way!
If I simply used my 3 pin charging cable in a socket in my house (through a window), would it cost me less in electricity? I appreciate that it maybe wouldn't charge as quick, (or would it?), but I charge overnight anyway, so speed and time isn't an issue, I'd just like to cut down on charging costs.
Do you have a 6.6kW option on your car?
 

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Thanks. Yes, that makes sense.
Is there a way of finding out how much electricity I am using through my home charge point? .
I use an IoTaWatt - each circuit on your CU has a CT installed, logging every 5 seconds, local logging, or online to eMoncms, Grafina, NodeRed etc - for the price you won't find anything more accurate or featured.

IoTaWatt Project
 

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Thanks. Yes, that makes sense.
Is there a way of finding out how much electricity I am using through my home charge point? I thought my electricity provider would know how much is being used by the HomePod specifically, but they said they can’t.
The way I do it is, although I don't have Eco7, I set my charge timer to start at midnight. Then on the days when I charge, my smart meter tells me how much my electricity has cost me so far that day when I get up, and I can also look at the daily history to see the hourly usage. Since very little else is running overnight, that gives me a pretty good estimate of how much my charging has cost me, especially when I subtract the residual amount on non-charging days.
 

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If I simply used my 3 pin charging cable in a socket in my house (through a window), would it cost me less in electricity?
It would probably cost you very slightly more, as it charges slower and so has to keep the car’s auxiliaries running for longer and so wastes more power on that rather than actually going into the battery. But that’s a very small effect.

It’s usually more helpful to think of charging costs in terms of pence per mile rather than the cost of any one particular session. If you know what you are paying for electricity (kWh), and divide by the miles per kWh figure from the dashboard that gives you a rough pence per mile figure; you should add about 10% to cover losses while charging.
 

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Discussion Starter · #12 ·
Which begs the question, why were you asking pod point about upgrading to 7kW?
It was to to enable me to charge my car quicker, as I thought it would use less electricity, but I’ve now realised that it would only speeed up the charging time, but use more electricity, so it wouldn’t really help cut costs. I now try and use local free 7kw charge points, a recently opened 22kw charge point or my local Nissan dealer who have a 50kw charger.
I originally changed electricity supplier from SSE to NPower as they had cheaper unit costs, but have noticed my usage go up, so am only trying to charge up once a week at home now. I also tried Economy 7 as I only charge at home at night, but the day unit costs were more.
 

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I thought you said your car had a 3.3kW charger. If that's the case, then plugging into a 7kW (or even 22kW) charge point won't make the slightest bit of difference, as your car will still only charge at 3.3kW maximum.

The Nissan 50kW charge point will be DC CHAdeMO which is the other socket on your car, and will give you a rapid charge - a completely different scenario.
 

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It was to to enable me to charge my car quicker, as I thought it would use less electricity, but I’ve now realised that it would only speeed up the charging time, but use more electricity, so it wouldn’t really help cut costs. I now try and use local free 7kw charge points, a recently opened 22kw charge point or my local Nissan dealer who have a 50kw charger.
I originally changed electricity supplier from SSE to NPower as they had cheaper unit costs, but have noticed my usage go up, so am only trying to charge up once a week at home now. I also tried Economy 7 as I only charge at home at night, but the day unit costs were more.
If your car could handle the extra, it would reduce both the charging time and energy required, as the overhead would be operating for less time.
 

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Discussion Starter · #15 ·
Thanks for all this, it just goes to prove how the knowledge of electric cars, especially charging, is still in it's infancy with the majority of the uninformed general public. I was told non of this information by the dealer, I've learnt more in the past couple of days from users on this site than I have since I got my car in March 2017. I still wouldn't go back to ICE though!
 

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Discussion Starter · #18 ·
Interesting regarding business mileage, as I used to home school, a few months ago, and the school had no idea what to put down for mileage, so they agreed on 25p a mile which I didn't complain about, especially as I used to charge my car at the actual school as well, and it was all official, as the caretaker was OK with it!
 

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Discussion Starter · #19 ·
In response to all the information users have told me, I’ve got a few questions, bearing in mind I am not an expert regarding ‘electricity’!
1. As I’ve said, I’ve got a Leaf with 3.3kw motor and a 30kw battery. Someone said even if I charged on the type 2 connector on my Leaf on 3kw, 7kw or 22kw chargers, I wouldn’t get any difference in charging speeds, so why do different network providers offer 3, 7, 22 or more kw chargers if everyone only charges at the rate defined by their cars motor? I presume all EV’s are different though?
2. Obviously when charging at the Nissan dealer on their 50kw unit using my CHAdeMO connector, I get a lot faster charging rate, so excuse my ignorance, but can’t I get an adaptor to connect lower speed charging points that I normal connect to my type 2 connector, to the CHAdeMO connector on my Leaf?
3. If Nissan could do it, no doubt at an extortionate cost, but would increasing my motor to a 6kw one, speed up the time needed to charge?
4. Is there an ‘app’ or an online calculator that I can use to enter the kw of my motor, charging speed of the charging unit and residual charge left on my car, to enable me or anyone to calculate how long it will take to get to 100% or other required percentage?
5. I accept that upgrading my Podpoint home charging point from 3kw to 6kw increase the speed of charging, but would it increase the amount of electricity used? I presume if it increased the speed, it would be on charge for less time and therefore use less electricity.
6. At a local 22kw charge point, I was chatting to the owner about ev’s, and he used a gadget to attach to the dashboard of my Leaf and showed me the condition of my battery cells, and said using fast charge charging points above 22kw, (presumably using the CHAdeMO charging point), detrimentally affects the condition of the battery, and that a slow charge is better for the battery.
For any lengthy replies, my email address is [email protected].
Thanks all.
 

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1. The motor isn't 6kW. It's a 80kW motor. That's the on-board charger that you're thinking of. They are correct. With AC charging, you're limited by the maximum current that your car's on-board charger can draw from the mains. My Leaf came from the factory with a 6.6kW on-board charger.
2. Any adaptor of which you speak to connect your household AC power to the DC chademo of the Leaf would effectively be the same as the rapid chargers - which are rather expensive. It may be worth keeping an eye on the vehicle-to-grid equipment that is starting to come onto the market that uses the Chademo DC charge port, and would allow your vehicle to charge at home faster than the on-board charger can normally handle it. It won't be nearly as fast as the rapid chargers, but it will be faster than the 3.6kW that your on-board charger can handle. It'll won't be cheap.
3. The motor isn't 6kW. It's a 80kW motor. That's the on-board charger that you're thinking of. Nissan don't have a defined process for replacing a 3.6kW on-board charger with a 6.6kW on-board charger. As such, you'll be hard pressed to find a dealer that will offer that upgrade. It's a lot of work, and you'll probably find it's cheaper to sell one vehicle and get a vehicle with faster on-board charging.
5. Upgrading your home podpoint beyond the rating that any vehicle you may connect to it is capable of drawing is pointless.
6. 22kW AC chargepoints won't affect your 3.6kW charging at all. If you rapid charge the vehicle and let the battery get overly hot with repeated charges and running, and not let it cool down, it will affect the long-term reliability of the battery pack. So it you drive thousands of km every day with multiple rapid chargers a day, it will take it's toll.

Charging from the 3 pin 'granny cable' brick is going to be slower than charging from your pod-point, since the 'granny cable' is only going to be offering the car 10 amps of charging, rather than the 16 of the pod-point.
 
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