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Comment by hwillis | Hacker News Reader

Very unlikely. Winter batteries aren't a huge problem as long as you are gentle until the pack is warm. Hot batteries are more of an issue, as they don't really like temperatures above 90-100 F. Keeping the battery at half charge helps reduce that damage a lot.

Ultimately if you live in a hot climate the best thing to do is have a cool garage. The higher heat while out and about is not an issue, just the constant level of high heat. The only people who would get a real benefit from high temperature batteries are those without. Batteries are much more expensive than tires and the market is smaller.

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Was wondering about if you could put a liquid coolant loop from the battery to the charging socket on the car, then have a heat exchanger in the plug and run water to and from it using a jacket round the cable, so you can have a rapid charge that also helps heat your bath water.

A supercharger tops out at 250 kW throttles down when the battery pack gets to ~115 F. Hot water heaters run from 120-140 F. Domestic circuits at at most ~7kW, so you'll realistically never be able to do anything useful with the waste heat. At low power like that battery charging is 98-99% efficient.

Another problem is that the coolant loop needs to be kept quite clean. The fins are only about a few millimeters wide and in some cars (eg Model 3) they're electrically hot. Any grit or buildup making its way into the system is a huge problem and just having a valve that can open can cause problems.

I'm talking about having a domestic supercharger. You can get up to 70kW at the company head fuse as a standard residential customer in the UK. You can also go higher, but you have to apply for a quote, so at the moment getting a true domestic supercharger is a bit pricy.

However, they are going to have to upgrade it all anyway if we get loads of electric cars.

As for the coolant loop, I wasn't suggesting to have a valve that can open, just a closed loop to the socket and a heat exchanger that then heats the water flowing through the handle of the plug.

You then store the water in an insulated tank and use it as a preheated supply feeding your main water heating system.

It’s probably worth it for locations that see extreme heat throughout the year though. Phoenix, LV, etc would probably be cheaper markets at scale with specially engineered batteries.

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