Why did old batteries need to be charged for 24hrs before use?

Question

Hey guys! I’m pretty young (15) and whenever I would get a new device for my bday or something, my parents always said that you needed to charge the device for 24 hours before you use it, and that you should always charge it up to 100% and use it until it hits 0% otherwise the battery won’t hold as much charge as possible. This kind of sucked because I of course wanted to play whatever it was right away instead of waiting until the next day, and I recently found out that you don’t have to do this on newer batteries but on older ones you do, which is how this “common sense” advice originated. However why did old batteries need to be charged for 24 hours before use, and used from 100% to 0% as it doesn’t seem like that should impact how much charge the battery can hold. Please ELI5.

In: 29

Answer 1

They didn’t need to be charged for 24 hours lol. They just needed to be charged until full and then drained until empty. They had a “memory” so in order to get the most use out of them on a single charge you needed to use the whole range to establish said “memory”. Most devices charged in like 5-6 hours so after that they were good to go. Most people didn’t understand exactly why though so you ended up with stuff like this. “Charge to full and drain to full so that it lasts longer”. I remember having devices that I’d use while plugged in constantly like a laptop and then once unplugged I’d be lucky to get 20 minutes of time. Replaced the battery and only plugged it in at sub 10% and unplugged at 100% and the battery would give me 2-3 hours every time. Old battery tech

That being said a LPT back in the day would have been “if you’re giving your kid something that needs to charge, precharge it for them so they can use it right when they get it”. As it is when we got my nephew his new Xbox for Christmas. I hooked it up and put the game he wanted most for it in the night before and got it ready to play then packaged it back up. When he first hooked it up to play instead of a bunch of downloads and patches it was just ready to go to start playing.