A difficult journey highlights issues with UK public charging infrastructure.

[Gadget Geek]

IKEA chargers are 40kW and cost 79p/kWh. Sainsbury's are 300kW @ 72p/kWh. I know which ones I'll be going for.

 

[Gadget Geek]

Journey completed, and as usual things didn't quite go to plan.

Started with 100% charge, and did 70mph most of the way to make sure we got to Hounslow West in good time (and it's a good job I did). Arrived with 31% and an efficiency of just 2.8mi/kWh, due to the speed and the heavy showers and surface water.

I got my daughter's suitcase out of the boot and we went around to the front of the station . . . only to find that the Picadilly line was closed all weekend for works. Brilliant! So we went over the road to the bus stop and started looking for which bus would take us to Terminal 3. There didn't seem to be a direct bus and everyone was getting buses. Brilliant.

My daughter had TFL web page on her phone which was really useful. Fortunately for us, a young Asian lady overheard us and asked if we wanted to get to Terminal 3. We said we did and as luck would have it, she worked there (I think she would usually have used the tube train). "Stick with me, I'll get you there" she said and she did.

Having seen my daughter off, I eventually got back to the car. All the roads around Heathrow were gridlocked, something to do with the car parks a man on the bus told me who worked for TFL.

The Guess-O-Meter said I had around 50 mies of range left, the chargers at Calcot were 35 miles which wouldn't have left me with much wriggle room on a motorway with no hard shoulder. So I diverted to The Charge Yard in Slough for a quick top-up. I got there with 25% and 45 miles on the GOM. I left with 35% and 70 miles range.

Now, this is the impressive bit . . . got off the M4 at J12, around the island and into Sainsbury's, it's that close to the junction. In fact, it's probably closer to the junction than the normal motorway services. There were quite a few cars charging, but I found a couple of empty ones and plugged in at 24% and 54 miles on the GOM.

It's a big Sainsbury's store so there was a lot more choice than at a motorway services and it didn't cost an arm and a leg. I scanned the QR code on the charger and linked my Nectar card to the charge to get some points. At 78% I was on my way with no worries. I can highly recommend these chargers if you are travelling on the M4 corridor.

 

[Gadget Geek]

P.S. What a difference in infrastructure from two and a bit years ago.

Oh, and stuck at 65mph on the way back and got 3.8mi/kWh.

 

[Bam Bam]

It's a big Sainsbury's store so there was a lot more choice than at a motorway services and it didn't cost an arm and a leg. I scanned the QR code on the charger and linked my Nectar card to the charge to get some points. At 78% I was on my way with no worries. I can highly recommend these chargers if you are travelling on the M4 corridor.

Good tip.

As you say, right by the junction and with facilities in the supermarket and shopping options, so it should be a popular spot. Also a MacDonalds drive thru.

I hope they left space to increase the number of chargers as time goes on!

 

[Gadget Geek]

I did the return run to Heathrow yesterday using Sainsbury's at Calcot, Reading. No problems at all.

On the way back, my guess-o-meter said I would get back with 30 miles left, which I have done before. However, I remembered the time I got stuck in traffic and how the stop/start driving sucked the electrons out of the battery, so I decided to call in to Sainsbury's again to use the facilities and grab a coffee.

I put 10% in the battery, and hey presto, as the M4 joined the M5, it was stop/start traffic all the way down to Clevedon. We got home with 34 miles left, which means I would have run out of charge somewhere near Gordano services so I would have had to call in there for a more expensive charge.

All in all, no different than driving and fuelling an ICE car on a long journey.

 

[Bam Bam]

the stop/start driving sucked the electrons out of the battery

This seems strange to me - is it from the extra time with AC on or something?

I would have thought that EVs are great at that sort of situation - no idling, regen, autohold, most efficient at 20mph rather than 50mph etc.

All in all, no different than driving and fuelling an ICE car on a long journey.

Glad things are improving and you are showing that there is no detriment to having an EV - all upside!

 

[Gadget Geek]

This seems strange to me - is it from the extra time with AC on or something?

I would have thought that EVs are great at that sort of situation - no idling, regen, autohold, most efficient at 20mph rather than 50mph etc.

I thought the same until it actually happened to me. It's all to do with overcoming inertia. A vehicle uses the most energy when tansitioning from a staionary mass to a moving mass. When it's moving, inertia becomes useful as it will keep the mass moving. Unfortunately at those low speeds, regenerative braking is practically non existent, so your battery depletes very quickly.

 

[Bam Bam]

I thought the same until it actually happened to me. It's all to do with overcoming inertia. A vehicle uses the most energy when tansitioning from a staionary mass to a moving mass. When it's moving, inertia becomes useful as it will keep the mass moving. Unfortunately at those low speeds, regenerative braking is practically non existent, so your battery depletes very quickly.

Yeah, regen never gets back what you use.

Still, I'm sure I've had better efficiency on a busy motorway than a free flowing one. I do drive very relaxed without increasing or decreasing speed too rapidly. People take advantage of this though as it means there are gaps in front of me into which they can slip.

 

[Gadget Geek]

Yeah, regen never gets back what you use.

Still, I'm sure I've had better efficiency on a busy motorway than a free flowing one. I do drive very relaxed without increasing or decreasing speed too rapidly. People take advantage of this though as it means there are gaps in front of me into which they can slip.

A good example is the 3 mile trip into town. In the early hours of the morning with no traffic and all the lights on green, at a constant 30mph I can get 5 m/kWh. During the day with traffic and variable traffic lights, I get between 3 and 3.5 m/kWh. Constant velocity gives the best efficiency.