Editing 2680: Battery Life

{{comic
| number    = 2680
| date      = October 3, 2022
| title     = Battery Life
| image     = battery_life_2x.png
| imagesize = 264x251px
| noexpand  = true
| titletext = It's okay, I'm at 10%, so I'm good for another month or two.
}}

==Explanation==
Smartphones run on batteries that require frequent charging; they may also be frequently replaced with a newer model by their user, though battery life is only one of several reasons why they may do this. In this comic, instead of charging his phone every day for a few years and then buying a new phone, [[Cueball]] has obtained a phone with a battery big enough to last supposedly until the phone will be replaced after a few years. This appears to make for a phone of cumbersome weight and size. According to the caption, 10% of battery life corresponds to 1–2 months; this suggests a total battery life and hence product life of 10–20 months, which is less than two years. A 'few' is generally [https://www.merriam-webster.com/words-at-play/couple-few-several-use more than that], even in the [[1070: Words for Small Sets|world of xkcd]]. (This assumes that he'd be 'good' right up until 0%. He could be just talking about being generally unconcerned until it reaches 5%, say, from which point he knows he'll have a similar further amount of time to start seriously thinking about arranging the full replacement, and all that this entails.) More practically, [https://www.forbes.com/sites/christopherhelman/2013/09/07/how-much-energy-does-your-iphone-and-other-devices-use-and-what-to-do-about-it/?sh=6f8e6fed2f70 a smartphone requires around 2 kWh per year] (assuming this is not otherwise an [[:Category:xkcd Phones|untypical phone]] in terms of power requirements), so this 12 kWh battery could have been expected to last even longer.

A 12 kWh battery weighing 100 pounds (45 kg) has an energy density of 264.6 Wh/kg, about equal to the high-estimate of the energy density of {{w|Lithium-ion battery|lithium-ion batteries}} of 100–265 Wh/kg. However, it is well below the practically achievable energy densities of (non-rechargeable, as befits the application) {{w|Zinc-air battery|zinc-air batteries}} at around 400 Wh/kg. Unfortunately, {{w|Self-discharge}} means that if this battery is lithium polymer, it will lose on average 5% of its charge per month, which totals to 46% lost each year. If this were a non rechargeable battery such a lithium metal, its battery life could be much longer.

This comic appeared on [https://techxplore.com/news/2022-10-eu-lawmakers-impose-charger-smartphones.html the same day that the European Union standardized charging adapters for mobile phones.]

This may be a commentary on very large external portable charging devices. At present (October, 2022) the largest cell-phone sized charging devices [https://www.amazon.com/dp/B09H4GLZXT/ hold almost 40000mAh and can weigh almost a pound]. Even [https://www.amazon.com/Jackery-Explorer-Portable-capacity-Emergency/dp/B0B8ZLZ53M larger devices are available weighing over 40 lbs] in different form factors. We buy cell phones because of their small size and convenience,{{Citation needed}} and end up buying extra external battery power for them that adds significant extra weight and bulk.

[[Category:Comics featuring Cueball]]
[[Category:Phones]]

==Transcript==
:[Cueball is seen carrying a large box. He is shown three times as he seems to turn and walk to the right in the same panel. He has trouble reaching around the box. In the first version a label can be seen at the bottom of the box, which indicated it is a huge battery. There are also unreadable text at the top. Cueball holds it in front of him, covering his torso and partly obscuring his head. In the second version he has turned to the right, and reveals that on the other side of the box there is a small phone in the middle with a keyboard. In the last version he has turned fully and it looks like he is walking to the right, but could also be that he is just leaning back to support the weight of the box. He is operating the phone with a free hand while he holds the box with the other hand, and are thus forced to lean it against his head for support.]
:Label: 12 kWh

:[Caption beneath the panel:] 
:Plugging in my phone is a pain, so I got one with a 100lb battery, and when it runs out of charge every few years I just upgrade.


{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Smartphones]]