Your Questions Answered: Why don’t EV chargers use your own cable?

I find the seat belt in my car uncomfortable and would like to use an extender I found online. Are these hard to fit, and do they need to be certified or engineered? – Gerry

Answer: Hey Gerry, seat belt extenders can only be used in a specific situation – where the belt cannot extend far enough around your body to latch. You cannot use one simply because it makes wearing the seat belt more comfortable. It can actually seriously injure you in a crash by exerting forces on your body in a way not intended by the seat belt alone. Seat belt extenders can also never be used to secure a child car seat, infant capsule or booster seat, again because an extender changes the way the seat belt operates in a crash – and not in a good way.

With seat belt safety cameras now commonly in use, you can also be fined if a camera image catches you using one, or if it is observed when you are pulled over by the police. Fines differ in each jurisdiction, but they currently range from $350 to $1200 or so.

However, a seat belt extender can be used if the standard seat belt will not reach around to clip in, for example, if you are heavily pregnant. If that’s the case, the seat belt extender must be Australian Standards-approved and labelled as such. Vehicle manufacturers can have different seat belt buckle designs, so you can’t assume one size fits all with belt extenders.

Beyond those requirements, there’s also a doctor’s certificate requirement. Each state and territory has a slightly different take on this. Most require a doctor’s certificate valid for 12 months; some require it to be carried in the car, while others require it to be logged with the relevant state road authority.

If legitimate seat belt extender use applies to you as laid out above, make sure you check the latest requirements in your state or territory before you go ahead, because those requirements can and do change.

Answer: Hi Adrian, it’s a shame that this type of theft and vandalism occurs. Sources suggest the copper yield from such a theft is marginal at best, so if that’s the reason, it is a gross miscalculation by the thieves – and if it’s ideological, it’s a strange way to voice an objection to EVs.

Anyway, you’ll notice that public fast-charger cables are a lot thicker than any portable charging cables, including ‘granny’ chargers that come with many EVs and PHEVs. That’s partly because they are designed to carry much more current – 100 amps or more, and up to 500 amps for an ultra-fast charger if the EV’s architecture is designed to accept that much – and this creates much more heat.

They do need a bit more copper wire to carry the current, but most rely on a coolant channel within the cable to ensure the copper wire doesn’t melt. This means they really need to be a permanent fixture. They also have thicker insulation to protect them in what is effectively a commercial operation.

However, many kerbside pole chargers are now being installed by councils, for example, that require a bring-your-own Type 2 to Type 2 charging cable. These can charge at 7kW or 22kW, depending on the location and what your EV can accept.

Looking at classic cars at a recent show, it occurred to me that steel wheels were the norm 30 years ago or more. Now it seems almost no new cars come with steel wheels. I get that alloys are supposed to be lighter, but I helped a mate chuck some 17-inch alloy wheels and tyres on his Yaris, and they were definitely heavier than the standard 15-inch steelies and the car felt slower. It had the correct rolling-radius tyres fitted, so it wasn’t that.

I also wonder why smaller steel wheels with taller tyres are not more popular, given the state of our roads and how easy it is to damage a low-profile tyre and alloy wheel – Justin

Answer: Hey Justin, alloy wheels were originally a way of reducing unsprung weight and thus allowing improved dynamics, but more recently it has become more complex. Alloy wheels – or aluminium alloy, to be technically correct – are cheaper to make with more modern production techniques, and their growing popularity and production volumes mean the per-unit cost is lower than it was.

They’re also easier on the eye to most buyers than old-school bare steel wheels or steel wheels with wheel covers. It’s a fashion thing now, mostly, although with some alloys it’s still a weight-saving proposition.

Not all alloy wheels are the same. Cheap cast alloy wheels are more brittle, thicker and heavier than more expensive forged alloy wheels. So a cheap set of aftermarket cast alloy wheels might not offer much weight saving over steel wheels of the same size.

If replacing a set of standard wheels with bigger ones – as in your example, with 17-inch-diameter wheels in place of 15-inch wheels – there’s more wheel material and the potential for more weight. Bigger wheels also tend to be wider, causing more resistance and drag.

Large-diameter wheels with low-profile tyres were – and in some cases still are – a way of improving car dynamics and providing better tyre options for enhanced grip. I don’t think we’re ever going back to steel wheels as the norm, but maybe we might see some paring back of huge alloys running rubber-band-thin tyres.

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