Path: ...!news.mixmin.net!weretis.net!feeder8.news.weretis.net!hugayda.aid.in.ua!.POSTED.localhost!not-for-mail From: usenet@dolik.dev (Andriy D) Newsgroups: comp.sys.raspberry-pi Subject: Re: Backup power supply Date: Fri, 15 Mar 2024 08:45:46 -0000 (UTC) Organization: Hugayda Station Sender: Message-ID: References: <710368823@f1.n770.z14837.fidonet.org> <65f36ffb@news.ausics.net> Injection-Date: Fri, 15 Mar 2024 08:45:46 -0000 (UTC) Injection-Info: hugayda.aid.in.ua; posting-host="localhost:::1"; logging-data="14222"; mail-complaints-to="usenet@hugayda.aid.in.ua" User-Agent: tin/2.6.2-20221225 ("Pittyvaich") (FreeBSD/14.0-RELEASE-p3 (amd64)) Bytes: 2232 Lines: 27 Computer Nerd Kev wrote: > Andriy D wrote: >> The Natural Philosopher wrote: >>> On 14/03/2024 07:57, Andriy D wrote: >>>> This is exactly my concern - I want this think up&running 24/7/365 and I don't want >>>> it to burn my house down :) >>>> I guess this is where you'd say 'risk' and 'price' are in a inverse relationship ;) >>>> -- >>> It is entirely possible to trickle charge a lithium cell at uber low >>> risk, Essentially you want to current limit the supply at at one tenth >>> of the hourly capacity so e,g a 2200mAh celll would need to be charged >>> at no more than 220mA, and voltage limit the charge at 4.2V. >> Majority of the schemes I've found so far suggest use of NiMH cells as >> they are less 'combustive'. > > Indeed, but if the power requirements are low (a Pi Zero without any > power-hungry USB/HDMI connections) then supercaps might be an easier > option. Since then you don't need to worry about over-charging, > which will still wear out NiMH, even if it doesn't then burn your > house down. I had this thought as well, as all I need is to have enough power to cover for a few seconds of a power outage or gracefully shutdown RPi if it's longer than that. Thanks for that link! -- Cheers, \aID