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Joined 2 years ago
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Cake day: July 15th, 2023

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  • Lithium-* batteries don’t actually have any specific useful numbers. It’s something like this (the actual numbers are pulled out of my ass and depends on battery time and test parameters and even then I’m simplifying):

    • At 0 volts, the battery is dead.

    • At 1 volts, the battery is practically dead.

    • Discharging to 2 volts kills it after around 100 times.

    • Discharging to 3 volts kills it after around 10 000 times

    • Discharging to 3.5 volts kills it after 100 000 times

    • Charging to 4 volts kills it after 100 000 times

    • Charging to 4.2 volts kills it after 10 000 times

    • Charging to 4.3 volt kills it after 1000 times

    • Charging to 4.4 volts kills it after 100 times

    • Charging to 4.5 has s significant chance of it catching fire

    Now choose how many charge cycles you want it to survive, and you know which voltage to consider 0% and which to consider 100%. The bigger difference, the bigger capacity with the same battery.

    This is why a phone with 0% battery can tell you that it’s out of battery.

    You can also adjust what “killed” means. Is it when battery capacity is reduced to 80%? 50%?

    I have to repeat - the numbers are not accurate, and this is strongly simplified.

    It’s just an illustration of what 0% and 100% means it’s just where you are on the useful range, according to the manufacturers definition of useful.











  • Oooh yeah, ISDN. My cable solution that I got in year 2000 (to answer OP’s question) didn’t work very well, and DSL wasn’t an option yet I think.

    For those ready to listen to my nostalgia:

    ISDN was awesome because even the smallest solution had two channels. So two phonecalls on one line. Great for businesses. Also, a channel had 64 kbit, slightly faster than the analog modems which I think maxed out at 54 kbit, which was often unlikely to be reached.

    But the trick is, the two channels could be combined to 128 kbit. An incoming or outgoing phonecall would simply reduce the speed back to 64, instead of interrupting the connection.

    Although I paid by the minute, and using two channels doubled the cost, so I usually only used it when I was literally waiting for a data transfer and would be paying the same price anyway.

    Actually, I think my ISDN would count as dial-up, as I paid by the minute.