> But then I needed to find a brake controller that can work with the higher voltage (14.4v vs the normal 12v)

Not understanding this sentence. Most running ICE vehicles product closer to that 14.4 than 12v. I think a standard controller would have worked fine?

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serf 11 hours ago | parent | next [-]

you're correct. a '12v ICE' alternator generates up to 14.8-15.2v. Most automotive stuff can operate between 9ish-16ish-v , of course totally depending on the product.

of course this is just a modern interpretation. older stuff runs at 6v and some weirdo offbeat cars have a 24v/48v rail sitting around somewhere. Cop cars often had alternators that put out weird voltage ranges for certain equipment, or dual 12v for high amperage output.

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kube-system 10 hours ago | parent | next [-]

Even just a "12v" automotive battery itself is mostly dead if if actually reads 12.0V. Fully charged is around 12.6 or 12.7. If a car had an electrical system that actually ran at 12 volts, the battery would always be dead.

"12v" in reference to anything automotive is very much a nominal reference.

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londons_explore 11 hours ago | parent | prev [-]

Whilst cranking, an ICE car will drop to around 6 volts (then maximum power is extracted according to thevenim's theorem).

That means all computers etc will work at 6v.

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toast0 11 hours ago | parent | next [-]

> Whilst cranking, an ICE car will drop to around 6 volts (then maximum power is extracted according to thevenim's theorem).

> That means all computers etc will work at 6v.

Not necessarily all of them. Plenty of stuff will drop out while cranking; hopefully not the computers that run the fuel injection and ignition, though.

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cogogo 4 hours ago | parent [-]

Interesting. I now know why my windshield wipers quit for a sec when my vw auto stop/start kicks back on.

	▲	Maxion 3 hours ago \| parent [-]
		Not a car engineer, but those motors can be pretty high A, so this could also just be a feature that helps the starter get as much power as it can while cranking.

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bluGill 11 hours ago | parent | prev [-]

The specs say no less than 6volts. In the real world when the temperature drops down to -70F or colder and batteries get old the voltage goes well below that: deal with it.

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hrmtst93837 an hour ago | parent | prev | next [-]

Voltage isn't the whole story, controllers also need to survive current spikes and power transients, and Tesla's rails may not look like generic 12V gear.

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LikeBeans 10 hours ago | parent | prev [-]

You are probably right. Surprisingly the first controller I tried didn't work. I assumed the voltage was too high since it worked in my other (much older) car. I found a reference online of people that tried a particular brand/model and that's what I went for. Thankfully my car isn't the model with the internal 18v battery.