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.

[https://microgreen.ca/energypak-lithium-batteries Portable (on wheels) 12 kWh lithium-ion batteries] do exist but typically weigh over 250 lbs and tend to lack ports to plug a phone directly into. Roughly 100 lb portable power stations can have capacities as high as [https://www.goalzero.com/collections/portable-power-stations/products/goal-zero-yeti-6000x-portable-power-station 6 kWh] and can be used to charge a typical smartphone directly hundreds of times.

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

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

:[Cueball carries a gigantic battery with a phone in it in three different positions in frame.]
:[Text on battery in first image:] 12 kWh
:[Caption:] 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}}