Charging efficiency and basis for payment

[Roy B]

As an aside, I was under the impression (please correct me if I'm wrong) that, at least originally, the metering at Superchargers was done by the car. If that is (still) the case, it will presumably have to change before they open up Supercharging to non-Tesla vehicles.

 

[NewbieT]

Ok, to take a completely different tack here. The terms governing BP Pulse say

They clearly talk about "electricity supplied to you" so I would say that if they charge you for more than the "electricity supplied to you" they are highly likely to be in breach of the contractual arrangements they agreed with the customer.

It could also be a fraudulent.

 

[Roy B]

Just to add, I have no idea how BP Pulse charge. It may be that they actually do meter DC (whether MID-compliant or not) or maybe they meter AC and adjust for charger efficiency.

Just suggesting that looking at charging networks contractual terms to figure out what they claim to charge you for may be a fruitful avenue...

 

[roadcred]

Come on get back on subject - this thread is about superchargers not BP Pulse

 

[GeorgeSymonds]

Moderator comment - posts taken out of the supercharging news thread as it’s gone off topic but an interesting topic in itself

 

[prabhu]

Talking of charging efficiency, I noticed that my home charger has an efficiency of around 85-88%. The key factors that seems to affect the efficiency based on my limited interpretation are weather and battery temperature.

 

[Mr Miserable]

OFGEM have done a wonderful job of completely screwing the domestic energy market in the UK and it seems they haven't finished yet.
Whatever happens on the EV charging front the involvement of OFGEM is something that must be avoided. I don't believe it was ever the intention for OFGEM to be responsible for EV charging and I'm not sure they are.
The first step they would have done would have been to introduce a scheme for charging operators to be licensed by OFGEM which they aren't and so therefore I conclude they are not taking any responsibility for this sector. Thankfully.

 

[Mr Miserable]

Talking of charging efficiency, I noticed that my home charger has an efficiency of around 85-88%. The key factors that seems to affect the efficiency based on my limited interpretation are weather and battery temperature.

Remember however that your home charger is not doing the conversion - your car is.

 

[rotor2k]

• Companies providing charger infrastructure are in it to make money
• So it makes sense (to me) that they would meter the incoming AC power (which is what they have to pay for)
• If there is any motivation to improve AC to DC conversion, it would be to compete against less efficient (and thus more expensive) competitors
• Presumably more efficient conversion is more expensive, otherwise it would be the standard -- either way the customer has to pay
• So maybe government regulation is required (e.g. all DC chargers must be at least 80% efficient)?
• Tesla could very well be operating the SuperCharger network at a loss as a marketing tool to sell more cars (do we know one way or another?)
• If you've ever used a Tesla SuperCharger, you know there are powerful (loud!) fans involved -- that's to get rid of the heat from the AC to DC conversion, which implies it still isn't super efficient

 

[LukeUK]

Talking of charging efficiency, I noticed that my home charger has an efficiency of around 85-88%. The key factors that seems to affect the efficiency based on my limited interpretation are weather and battery temperature.

A 'home charger' is EVSE - 'Electric vehicle supply equipment'. It's not doing any charging. The box(es) only provide;

- Protection (against over-current, residual current, open PE, etc.)
- Hardware for the other half of the handshake process with the car - via the two extra pins in the type 2 connectors.
- On/off switching of the mains AC, to the car (a relay or contactor)

The car's onboard chargers are used for charging the battery. There are three, rated at 16 A each. Two are used for single phase charging (max 32 A, 7.5 kW) and all three are used for three phase charging (16 A, 11 kW).

 

[Adopado]

A 'home charger' is EVSE - 'Electric vehicle supply equipment'. It's not doing any charging. The box(es) only provide;

- Protection (against over-current, residual current, open PE, etc.)
- Hardware for the other half of the handshake process with the car - via the two extra pins in the type 2 connectors.
- On/off switching of the mains AC, to the car (a relay or contactor)

The car's onboard chargers are used for charging the battery. There are three, rated at 16 A each. Two are used for single phase charging (max 32 A, 7.5 kW) and all three are used for three phase charging (16 A, 11 kW).

Which is why the pedants amongst us try to remember to refer to an AC "home charger" as a "charge point" ... EVSE is even more accurate, of course, but can be confusing for the uninitiated. It's not a charger because as explained above the charger is in the car. The car is simply receiving mains electricity. All the stuff in the box is for safety and smart switching.

 

[Roy B]

I don't think it's worth getting too hung up on the difference between "charger" and "charge point" when using non-technical language. Everyday language and technical language are used differently. It remains to be seen what terms will become preferred in everyday language, although I suspect that "charger" may well prevail

Besides, many pieces of consumer electronics come with AC adapters that are typically not, strictly, chargers, but are usually referred to as such. In the case of phones, some (but not all) fast chargers operate much like DC rapid chargers, outputting a variable DC voltage commanded by the phone, so arguably could be called chargers. Typical dumb "phone chargers" just output 5V DC and rely on a charging circuit inside the phone. But, just to add to the confusion, most fast "phone chargers" can operate in both modes. So the same device may sometimes be a charger and sometimes not. You can tie yourself in knots with this stuff.

Rule of thumb, in everyday language, we name things by how they are used, not by how they work internally (which in many cases we don't even know).

Bottom line: a home charge point and a USB "charger" are both devices used for the purpose of charging things. I have no qualms calling either of them chargers in everyday language. When speaking about technical matters, I will make such distinctions as are appropriate (and bearing in mind that terminological conventions often differ markedly between fields).