3 ms·
Smartphone Battery Recharge Time
- theamk 4y agoAlmost every technical fact in that post is wrong. - The LiIon batteries in phones cannot be charged to 5V. going above 3.7v or 4.2V (depending on battery chemistry) will permanently damage battery and/or will catch it on fire. - If the battery's internal resistance is 1 ohm, it means it is very bad and should be thrown away. A good battery's internal resistance is 0.05 - 0.001 ohm range. - Because of that, when charging batteries, you cannot connect it to power adapter directly -- with internal resistance that low, it will try to draw tens of amperes and will overload power adapter and/or overhead and catch fire. - That's why cell phone has a complex charger chip, which regulates input voltage into whatever voltage/current is required for battery. In most phones it uses DC/DC convertor for higher efficiency/less heat dissipation and has temperature sensor to prevent battery overheating. - This means all the graphs in the post are junk. (And in the retrospect, it is kinda clear... the second one says 5A / 25W if charging a fully discharged phone. As many adapters are only rated 1-2 amps and cables have similar rating, having this current will destroy the power adapter and melt the cable. And many people charged the phone from 0% before, many times, and there were no significant heating compared to say charging from 40%.