eli5: How come an old Nintendo DS battery lasts forever and will play for a long time on a charge but modern phone batteries deteriorate so much within a few years?

Question

My 15 year old well worn DS lite seems like the battery capacity hasn’t changed at all over time, but my 6 year old Galaxy S6 has a very noticeable quickly draining battery. I think processor and system load has something to do with it but they are both lithium ion I believe. Me no get

In: 1

Answer 1

Phones have increasingly more tech put into them over the years, with ~~great power comes great responsibility~~ higher battery drain.
Batteries wear out due to things like charging cycles, heat, how fast they are charged, etc.
A DS may not draw as much from a battery so the battery cycle isn’t repeated as much. Additionally, it might not put as much of a load on the battery causing a voltage drop.

In addition to the phone being a higher draw device than a DS, the phone probably went through charge/discharge cycles daily with use. If it was plugged into a faster charger, then that also would have caused more battery degradation.