OT - 3 pin home charger for EV

No direct experience, but I think they're much of a muchness really.

I'd just search ebay for 'ev cable (granny,13a)' and see what turns up in the length you need. In particular, since there is no power electronics in the cable (just a contactor and some low voltage stuff to set the charge current) there's not much to go wrong in them.

I expect all of them will allow you to select between 6A and 10A, but it's worth checking. (the EVSE protocol does not allow intermediate steps, so those are the only currents available from a 13A plug)

Theo

I got my granny charger from Tough Leads, who offer this comment:

Adjustable charging rate 6A, 8A and 10A on 20m, 25m and 30m.

In addition, the 5m, 10m and 15m also have a 13A option, which must only be used when connected directly to a BS1363-2-EV rated socket.

Programmable delay in charging starting (by pressing a button each time), in order to take advantage of cheaper overnight tariffs.

Advanced fault detection.

Extremely robust enclosure, IP67 rated (protected against powerful water jets from any direction). Heavy duty H07BZ-F rubber cable.

Plug temperature sensor ceases charging if the temperature rises above an acceptable limit for added peace of mind.”

Note that their prices are ex-VAT and carriage.

Check the specs for the lead you referred to, to see if it offers the same sort of plug-overheating protection, and contains a Type B RCD (30mA AC and

Thanks - good points on the protection etc. Quite pricey though . . .

Er no. And don't think it wasn't discussed. At length :-) But we are where we are . . .

Yes, looks nice. I'll look to a wall soltion in the medium term. For now though a 3 pin version will do fine. I don't do many miles and the battery is quite small (30kW/h).

Thanks - the lower current option is certainly something I'd like as it's likely to be used on existing ring circuits, rather than a dedicated spur. Although I'll put one of those in at home in the fullness of time.

I was tempted to go with a vehicle branded second hand charger cable but so far as I can see they don't seem to offer lower (say 6A) charging.

Don't know how your car works, of course, but with my last Renault charging got more than proportionally longer with low-power charging. I think the overheads, such as all the fans and maybe cooling pumps running, take up a larger fraction of the mains power leaving less for actual charging, as well as the effect of the efficiency of the converters in the charger at less than maximum power level.

It can take long enough at 10A, let alone 6A!

nib

Going slightly OT here, but in general there’s some tips you might find useful.

Like I did, you’re coming to EVs in the warmer weather. In the summer you can cruise down the highway at 50mph and get 10 miles/kWh. In winter, the battery efficiency drops, there’s heating and aircon and lights, and rate of usage plummets to 2 miles/kWh.

As a general rule, in use don’t let the battery fall below 20% capacity, and don’t charge to more than 80% unless you’re planning to drive off straight away - standing at full charge can shorten the battery’s life.

If the temperature falls to near freezing, make sure your battery level is

IMO faster chargers don’t help battery life. With the pattern of use you hint at, charging frequently avoids situations where you need to use the car but battery levels are low, especially true in winter for the reasons mentioned.

For the first few charges, monitor the wall socket temperature every now and then. I use a Bluetooth temperature placed on top of the wall socket, it shows a 2degC rise while charging at 10A.

You’ll love the boodles of torque available at zero RPM, and the flat torque response throughout the speed range.

One of the ingredients to charging, is "preconditioning".

Even on a fast charger, the charging does not start right away, until the battery is warmed to the right temperature. Some reviews of BEVs, the reviewer mentions "I preconditioned the battery while I was driving to the charger, where the

If you trickle-charge, it's still going to charge, but a certain amount of current would be required just to keep the battery temperature elevated above ambient. The target temperature might be 30-35C or so, as a guess. If you trickle charge when the ambient is 0C in the out of doors, heat from just the charging process may not be enough to maintain the target temperature. It might charge-for-a-while, heat-for-a-while (heat pump), charge-for-a-while, if the current applied it too low. At some level of current, it will be getting warm enough to keep charging. When fast charging, the heat pump could be functioning in cooling mode on a continuous basis.

You can test this yourself, or find a web forum where someone has already tested at 6A and 10A for a certain-ambient. The status displayed on the car screen, should be able to tell you what phase of operation it is in (pre-heat, charging 1 mile per hour of charging, charging 10 miles per hour of charging, stopped-charging-as-input-power-is-not-stable).

Cars monitor input power quality, which is a weird thing to do, and can disrupt the best-made-plan. For example, if you were thinking of charging using a Honda petrol generator, that might not be stable enough in frequency and voltage, as judged by the car computer. The car not only tells you when it is time to drink coffee, it also makes fun of your attempts to charge it :-)

Paul

Um, I’m calling bullshit.

You might see an instantaneous reading of that sort of level with the wind behind you but it’s in no way representative of “normal” EV power consumption. Much more typically in the 3-5 miles/kWh for a journey. At

Tim

Driving the 100 miles from the garage, it used about 70% of the battery with a reported 38 miles remaining. That was with everything on auto on a cool dry day. I took it easy to start as the it was indicating an 80 mile range when I set off. It stayed at that for about 30 miles so I did the remainder at 'normal' speeds.

So pretty much optimal, and chimes with the manufacturer's maximum of 140 miles. Given the car is 5 years old, that seems to suggest that the battery's OK.

Interesting, thanks.

Yep! Quite used to hot hatch levels of performance - this EV is very nice indeed.

You need to think about the deliberately specific phraseology of “…cruise down the highway at 50mph and get 10 miles/kWh”. That *will be* an instantaneous reading, but quite relevant if you’re doing a 50-mile journey on clear A-roads, because that instantaneous reading could last a hour.

JFTR my average consumption over nine months is 3.5 miles/kWh. I have a large proportion of short, urban, hilly journeys in that.

HTH

I have a PHEV rather than a BEV, its battery is just under half of yours. I have switched to an EV electricity tariff, but I think I'd resent not being able to do a full daily charge within the allotted 5 hours ...

Ah… Don’t trust the range reading (sometimes referred to as a Guess-o-meter). As battery levels fall, the battery voltage falls meaning fewer kWh than expected, and it’s been known that the readout can decrease faster than the miles you cover.

The figures you mention (100 miles, 70% of 30kWh) suggest an average consumption near 5 miles/kWh, not bad at all.

The big thing for general use is to recharge frequently to 80%. On my EV there’s a trick use of the programmable charging routines that means I can plug in at any time of the day or night, any day of the week, and it will charge to 80% then stop; it’s a very useful facility.

In the fullness of time you might like to try an experiment: charge to 80%, use the car until the level falls to about 40% (take an accurate readings from the car’s info), and recharge the battery noting how many kWh were used. Say that was 12kWh, this represents 80%-40%=40% of battery capacity.

It’s dead easy to spin the wheels on a damp road!

I really like the smooth torque delivery, manoeuvring in car parks is dead easy, the car is quiet, and you can park up and keep the aircon running without annoying anyone. Great whatever the weather if you’re waiting for someone.

Thanks - plenty to look at there.