EV Q&A: Why does our car not work with some chargers?

Irish Times

13-05-2025

Q: While in Mallorca this summer, my husband was eager to hire an
electric car
(apart from it being cheaper than petrol alternatives). At the airport, we were upgraded to a
Polestar 2
and headed off. The next day, my husband went off to try out charging/paying at charging points. We couldn't get any points to charge the car! After two days, we had to drive back across the island to the airport before the battery ran flat. The car hire company took the car, and went off to charge it, which failed as well. Not only did it fail, but every charging point it connected to was put out of service. My question is: why are the charging points not more resilient? The car hire company told me that more than 30 per cent of the charging infrastructure was down at any one time in Mallorca.
– K Woollett, Co Dublin
A:
That 30 per cent of chargers being out of action at any one time is, worryingly, not an unrealistic figure. While most charging providers will claim to have at least 90 per cent reliability, figures from the Competition and Markets Authority in the UK show that anywhere between a tenth and a quarter of all public charging points are out of order at any given time, and that 30 per cent outages are far from uncommon.
However, that wasn't really your question, your question was to do with specific cars and specific chargers. It should be simple, charging. After all, it's plugging an electrical device into a power source – something we do at home many times per day and something we've all been doing since Thomas Edison nicked Nikola Tesla's good ideas ...
While the odd blown fuse might be excusable, the sad – and deeply irritating – fact is that plugging in an electric car just isn't so simple.
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For a start, EVs work off at least a 400-volt, and increasingly an 800-volt system. That's a voltage that would be instantly lethal to you should anything go wrong and you came into direct contact with the current. So there are layers and layers of safety locks that have to be satisfied before current can start to flow, all the more necessary if it's raining (which, in fairness, I assume it wasn't in Mallorca…).
So there are plenty of opportunities for software issues to arise simply by taking the safety locks into account. Your issue did seem to be very strange, though, so we contacted Polestar to see if they could shed any light on it.
However, they couldn't – partly that was simply due to not being able to have access to the car and therefore not really being in a position to comment, and partly because they were working on the assumption that any issue with charging will be down to the charger, not the car, as car makers work hard to ensure that all cars are compatible with all chargers.
That makes sense, of course, but perhaps it doesn't always work. On the one hand, the Polestar 2 uses well-proven battery and electronic systems from Volvo, which shouldn't present any problems.
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On the other, coming from a car-hire firm, perhaps this particular car hadn't been properly set up before it was released out into the car-hire wilds, and maybe that's the source of the issue.
Or, it could be a proper mystery. For instance, we've been in contact with an EV owner in the UK, who has a home charger provided by PodPoint.
In the past, this charger has worked flawlessly with a first-generation Mini E, a BMW iX3, and a Porsche Taycan. However, when this person purchased a new-shape Mini Electric, brought it home, and plugged it in ... nada, nothing, a big fat nope on the charging front.
Cue a flurry of phone calls between the owner, Mini, and PodPoint which resulted in, as this person told us: 'A lot of shrugging emojis ...'
It did seem to be a broader, known problem though, of this new generation of electric Mini simply not recognising a PodPoint charger, or vice versa. And this is not an isolated problem – PodPoint is one of the biggest charging suppliers in the UK.
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Finally, a month into ownership, a reflash of the software controlling the PodPoint charger did the job, and the Mini is now charging properly. The problem? No one seems to know why, so it's not clear if the problem has been permanently fixed or if it might recur.
It gets dafter. Coming soon will be a new EV that will be entirely and deliberately incompatible with huge swathes of the charging network.
Mercedes is about to launch its new, ultra-long-range CLA electric saloon
, with an almost 800km range. That's some range, but don't expect to be able to top it up easily when you're out and about.
Mercedes has designed the new CLA around an ultra-fast 800-volt charging system, which makes it ridiculously quick to charge. That's nothing new, as Audi, Porsche, Kia, and Hyundai have had 800-volt charging systems in some of their models for some time now.
However, those Audi, Porsche, Kia, and Hyundai systems are back-compatible – in other words, if you plug them into a public charging point that works on a 400-volt system, and that's nearly all of them, then those cars can happily use 400-volt charging, they just won't charge up quite as quickly.
Not so the new Mercedes. The company is already warning potential buyers that the CLA simply won't work with 400-volt chargers, and can only be charged either at home on a slow wallbox charger, or on a high-powered 800-volt public charger.
That means most of the public chargers we have right now are going to be off-limits for the CLA. Remember when Apple ditched the headphone socket and made you buy Bluetooth buds? Yeah, like that only now you're stranded at the side of the road (to be fair, with an 800km range, that's unlikely unless you're very careless).
I feel as if we haven't really answered your question, and to be honest it's because we actually can't.
Electricity should be simple, well-understood tech, and for the most part it is. But there is a faint whiff of mystery when it comes to the electronics that control the flow of that electricity, and it can be moody and capricious stuff.
Until that's better understood, there will be moments when any of us will pull up at a charging station and it simply won't work for us. And there will be no easily explicable reason for that.