Speak EV - Electric Car Forums banner

1 - 8 of 8 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter #1
Hi all,
Just ventured for the first time into the world of EV's with a Mini Countryman PHEV. So far so good, but I have a query when it comes to the charging.

When an EV is fully charged, does there still exist a 'trickle' ? I've noticed a sustained draw after what I believe the car should be fully charged.

I've not yet had a home charger installed - so this is just using the 3pin cable. I think that charges at 2.3kWh - taking ~3.5 hours to charge from 0%.

Looking at British Gas's website, I can see my energy usage, down to a particular hour. Before the EV was acquired, my kWh usage after 6pm was around 0.10 - 0.20 maybe 0.30 kWh per hour .. same at 6pm, 7pm all the way through until maybe 7am the following morning.

Upon plugging in the EV, the draw jumps to around 1.5kWh (why 1.5 and not 2.3?). After a few hours this drops to 0.8kWh .. and stays like that until about 2/3am in the morning.

Maybe the granny plug is not charging at 2.3? Is that possible ?
 

·
Registered
Joined
·
3,642 Posts
I'm trying to understand your post. The British Gas website will presumably show your usage in kWh, i.e. rate (kW) times time (h). Is the histogram in 1 hour intervals, or half-hour intervals? If half-hour, then a usage of 1.5 kWh in half an hour is a rate of 3kW. I'm assuming the web site can't show instantaneous rate in kW. Your granny charger will charge at a rate of approximately 2.3kW (no h!). The charge rate will taper off as the battery becomes full - this is normal.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #3
Thanks for taking the time to reply JeffG. I'm a smart(ish) bloke .. but electricity gets me beat - so forgive some simple misunderstandings.

The BG website shows kWh at 1 hourly points. Here's a screenshot from 17th September. The car was not plugged in at all this day. You can see that on this day, after 6pm, peak was about 0.4kWh, dropping to <0.10 later on.

123006


Moving onto 18th Sep .. car was plugged in about 5pm ish - where you can see the large spike - upto just under 1.6kWh. The car remained plugged in until 6am the following morning.

123007



So I'm not understanding why,
a) why 1.6kWh (basic knowledge of electricity lacking no doubt)
b) if the car was fully charged by about 8pm on the 18th - what the 0.8kWh was .. as you can see - without a car plugged in, usage is circle 0.10kWh. I'm not expecting you to know everything else plugged in in my household, but assume the only change is the car being plugged in over night.

thanks again for taking the time to reply .. appreciated.
Andy
 

·
Premium Member
Joined
·
9,864 Posts
The invervals are 30 mins, so the 0.7kWh (delta) consumed in 30 mins is 1.4kW load, so is probably the car still charging. It will ramp down towards full, but are you saying it carried on at that rate after midnight? If so, perhaps you have preconditioning enabled and it was trying to heat car?

The delta at 6pm is ~1.1Kwh so a load of 2.2kW which is about right at 10A.

Just and aside, but bear in mind the grid is typically "dirtiest" at the time you charged. If you bought the car to help with environmental issues, then it would be better to charge in the early morning hours. I assume the Mini has a delay timer feature - most PHEVs do.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #6
Ahhh - I missed that .. so Jeff was bang on the money .. 30 minute intervals not 1hr .. doh!
 

·
Registered
Joined
·
5 Posts
Discussion Starter #8
Update ... after 3.5 hours charging tonight, from 0% off the 3pin... the car was at 50% battery.

So I think that explains why British Gas carts are showing higher than normal usage for 7ish hours ... its because its taking 7 hours to charge.

But it seems to be varying the draw ... sometimes 1.6 .. sometimes 0.8.. reflected by what the BG Smart Meter says too (live readings).

Will see what the charts show over the coming days.
 
1 - 8 of 8 Posts
Top