![]() 06/16/2020 at 16:11 • Filed to: None | ![]() | ![]() |
Wait, no, that came out wrong. What I mean to say is that that black tumor on the positive terminal there is an explosive battery quick disconnect . In the event of an accident, a tiny explosive charge immediately severs the high power circuits to the alternator and starter. This is done to reduce the likelihood of a fire if the crash shorts one of them out. Low power systems like the hazards and car phone are kept online so they can be used in the immediate aftermath. The whole sequence takes 30 milliseconds
![]() 06/16/2020 at 16:30 |
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All of which potentially makes a small fender bender much more irritating. Someone needs to introduce the designer to the concept of why breakers are better than fuses.
![]() 06/16/2020 at 16:32 |
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This is interesting. Is BMW first to this tech or did another manufacturer come to market first?
![]() 06/16/2020 at 16:34 |
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Many Fords have (or had) an impact-triggered breaker at the fuel pump for similar reasons. But--key point--you could just reset those. Didn’t need to replace parts.
![]() 06/16/2020 at 16:35 |
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I think it only deploys if there's an airbag deployment, in which case there's already gonna be a substantial refit of the car if not a complete totalling
![]() 06/16/2020 at 16:35 |
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To be fair, for a safety system you want a fuse since they will interrupt power much, much faster than a breaker (which needs time to heat up, though still on the order of milliseconds ). Still a pain in the ass if it goes off when it oughtn’t, though.
![]() 06/16/2020 at 16:37 |
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BMW's been using it since the mid 90's
![]() 06/16/2020 at 17:25 |
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That’s better at least.
![]() 06/16/2020 at 18:14 |
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I prefer my car to finish me off the job in the event that I attempt to end its life.
![]() 06/16/2020 at 18:42 |
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On the subject of exploding BMW batteries I’m recalling my last BMW which, for reasons inexplicable, had a bright red cable coming off of the negative terminal on the battery...
![]() 06/16/2020 at 19:28 |
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Meanwhile I have a UPS that does actually explode batteries once in a while. I don’t actually here them go off, but I notice it not working in failure, pull the battery, and find that the battery casing has been violently blown open . I’m not sure if it’s defective, but I have another very similar one which doesn’t see battery failures like that.
![]() 06/17/2020 at 20:56 |
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and only ~$600 to replace