Comment on Self-Hosting A Cluster On Old Phones

• suigenerix@lemmy.world ⁨6⁩ ⁨days⁩ ago

  At all? What do you believe the fire hazard is then?

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  • anzo@programming.dev ⁨5⁩ ⁨days⁩ ago

    Adding a high quality smart switch to a 5-year old battery might do some good, of course. But this is a cluster of old batteries, all in bad shape for many years of usage under different circumstances, temperatures, etc. And they’re all different models. Each battery will need a different time for going from 20 to 80%… it’s wild.

    I do this kind of risk assessment on the worst scenario, a fire could turn your home into ashes. The only option to me, being strict, would be removing those batteries (after all, your main goal is to re-use the other hardware.) But that’s only possible in a handful of phone models… it’s just unfortunate. I guess I should get a FairPhone next time!

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    • suigenerix@lemmy.world ⁨3⁩ ⁨days⁩ ago

      The person I responded to only has one device. But even if there were multiple devices, you could just have a smart switch per device.

      The fire hazard issue is that holding the battery at 100% increases the internal chemical stress on the battery, and increases the risk of thermal runaway. So keeping it well below that will definitely have significant benefit. Ideally, trickle charging it at around 50% would be best for almost eliminating further strain. (But you’ll likely need to charge it from 20-80% occasionally to help the battery management system keep calibrated.)

      And things can be done even smarter. Like only charge the battery at the coldest part of the day, typically early morning to reduce heat stress. Or throttle the device if it’s temperature reaches a threshold. Etc.

      Yes, if you can remove the battery, that’s helpful. But keep in mind you lose the benefit of battery backup during mains failure.

      Also, mobile phone fires get a lot of media attention because “drama,” but they’re not the hazard everyone thinks they are. You’re far more likely to have a house fire from rodents chewing into electrical cables, clothes dryer lint catching fire, or anything with a heating component. Ebikes and escooters are far more likely to catch fire than phones.

      The point is if you’re not emptying your dryer lint filter every use; if you’re not getting home pest inspections every six months and putting down rodent traps or baits; if you’re not getting your heating-element devices professionally checked regularly; if you’re not storing your ebike well away from flammables; etc., then worrying about phone battery fires is ridiculously out of proportion.

      I’ve got a colleague who says she’ll never buy an electric car because of the fire risk. But then she drives around in her gas car which is 8,000%+ more likely to catch fire.

      If you’re still paranoid, keep the device in a non-combustable container away from flammables, and near enough to a smoke detector. It’s easy to setup something that if the phone catches fire it’ll just burn itself out.

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