Why are electric car battery estimates so much more accurate than laptop and phone battery estimates?


My <1 year old laptop turned off today while saying it had 7% and 24 minutes of battery remaining. In my limited experience, electric cars just don’t do that. They provide a much more accurate estimate of how much juice they have left. Yet both use lithium ion batteries.

In: Engineering

Have you edited your laptops critical battery settings? They tend to toss themselves into hibernation when they hit a predetermined critical level of battery by default, usually 4-7% at factory setting.

I don’t have any source for this, but this is my best guess:
Cars on average use a pretty specific amount of energy per mile travelled. Especially in modern times being able to estimate acceleration from maps and autopilot. So one mile tends to equal a certain number of gasoline/electricity/whatever fuel your car uses. With computers, the power drawn is drastically affected by the usage conditions and those estimates tend to be created from now-minus-a-few-minutes-extrapolated averages. You’ll notice if you boot up a game on your computer or do something processor intensive, the fan starts going crazy because more heat is being produced, because the processor is working harder, and therefore using more energy. So any given second due to background downloads, software freezing, starting, closing, automatic brightness adjustments, etc, the use time could change. I often see my phone that has been on sleep mode for a while show “8 hours remaining” on 10% battery. That’s obviously never going to happen if you’re using a phone, even on a full battery.