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As a fan of Tesla's efforts, it pains me to read this; no matter where the blame lies (physics, bad planning, poorly tested diagnostics software) this article w

As a fan of Tesla's efforts, it pains me to read this; no matter where the blame lies (physics, bad planning, poorly tested diagnostics software) this article will haunt the company for years. Every oil lobbyist will eat this up, and it should become the foundation of any EV-haters argument. And that sucks. However, I'm annoyed that Tesla's UX people let a car with this much design intelligence leave without connecting range estimations to a simple thermometer. I understand that to HN readers batteries in the cold is "simple physics" but if the battery indicator jumps around like a BitTorrent download time estimation, people will quickly learn to not trust what the car tells them. Consumers that are highly neurotic about the road trip problem are much more likely to remember these sorts of horror stories when making a purchasing decision.

CamperBob2 14y ago
Also, the idea that recharging stations spaced 200 miles apart are in any way adequate for a 265-mile trip is just... weird. Would you trust your laptop or cell phone's battery life estimate to that extent?
fernly 14y ago
But if I read the article right, the car IS adjusting its display for temperature. When the temp went down, the calculated available miles went down also -- and almost accurately, that is, the car went dead about when the miles-left display went to zero. The question I'd have is, how much current would they have to divert to keep the batteries warm? It seems like the juice expended to hold the battery pack at 20C might be less than the capacity lost by letting the batteries go down to an ambient -5C. Or, they could provide what a lot of east-coast cars have, a built in engine-block heater that you plug in to a 110V extension cord overnight. Except in this case it would be a battery pack warmer, but the same idea, keep the important bits toasty over a cold night.
- chrisbolt 14y ago
  When the temp went down, the calculated available miles went down also -- and almost accurately, that is, the car went dead about when the miles-left display went to zero. Showing that the range is zero when the battery is dead is not hard. The problem is when the displayed range drops faster than you're traveling, and if that wasn't the problem, he wouldn't have been stranded. If it was adjusting its display for temperature, it wouldn't have been wrong. Or, they could provide what a lot of east-coast cars have, a built in engine-block heater that you plug in to a 110V extension cord overnight. Had he plugged the car into a 110V outlet overnight, the battery would have been charged in the morning.
__--__ 14y ago
It's going to haunt not just Tesla for years, but all electric vehicles. And with good reason - calculating the remaining potential energy of Lithium batteries is difficult, even without throwing in the variable of temperature. It is not, by any means, "simple physics". The battery is a weak point in all EVs right now, and not just because of this. Full disclosure, I own a Zero motorcycle. The thing is amazing in SF city traffic. It's less amazing on the highway. You should read up on Terry Hershner. He's taken a Zero motorcycle cross country by driving for 45 minutes and charging for 45 minutes. So, it can be done, but road trips are not the optimal use case for an electric vehicle. yet. :)

CamperBob2 14y ago

Also, the idea that recharging stations spaced 200 miles apart are in any way adequate for a 265-mile trip is just... weird. Would you trust your laptop or cell phone's battery life estimate to that extent?

fernly 14y ago

But if I read the article right, the car IS adjusting its display for temperature. When the temp went down, the calculated available miles went down also -- and almost accurately, that is, the car went dead about when the miles-left display went to zero. The question I'd have is, how much current would they have to divert to keep the batteries warm? It seems like the juice expended to hold the battery pack at 20C might be less than the capacity lost by letting the batteries go down to an ambient -5C. Or, they could provide what a lot of east-coast cars have, a built in engine-block heater that you plug in to a 110V extension cord overnight. Except in this case it would be a battery pack warmer, but the same idea, keep the important bits toasty over a cold night.

chrisbolt 14y ago
When the temp went down, the calculated available miles went down also -- and almost accurately, that is, the car went dead about when the miles-left display went to zero. Showing that the range is zero when the battery is dead is not hard. The problem is when the displayed range drops faster than you're traveling, and if that wasn't the problem, he wouldn't have been stranded. If it was adjusting its display for temperature, it wouldn't have been wrong. Or, they could provide what a lot of east-coast cars have, a built in engine-block heater that you plug in to a 110V extension cord overnight. Had he plugged the car into a 110V outlet overnight, the battery would have been charged in the morning.

__--__ 14y ago

It's going to haunt not just Tesla for years, but all electric vehicles. And with good reason - calculating the remaining potential energy of Lithium batteries is difficult, even without throwing in the variable of temperature. It is not, by any means, "simple physics". The battery is a weak point in all EVs right now, and not just because of this. Full disclosure, I own a Zero motorcycle. The thing is amazing in SF city traffic. It's less amazing on the highway. You should read up on Terry Hershner. He's taken a Zero motorcycle cross country by driving for 45 minutes and charging for 45 minutes. So, it can be done, but road trips are not the optimal use case for an electric vehicle. yet. :)