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A comment on Hackberry-Pi_Zero – A handheld Linux terminal using Raspberry Pi Zero 2W. Parent comment

Re:Hackberry-Pi_Zero – A handheld Linux terminal using Raspb... by teraflop on Friday August 02, 2024 @01:41PM (#41140883)
It would be convenient if it worked that way, but since the batteries are connected across each other in parallel, they will both be discharged simultaneously. And as soon as you hot-swap one of the nearly-discharged batteries for a charged one, it'll be more-or-less short circuited across its discharged counterpart.

To do what you describe, you would need additional components to "switch" one battery at a time into the power path. (This can be done with a single transistor if you're only worried about current flowing in one direction, but I believe it's trickier if you want to support both charging and discharging in the same circuit.)

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Re:Hackberry-Pi_Zero – A handheld Linux terminal using Raspb... by dheera on Friday August 02, 2024 @02:58PM (#41141565)
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Re:Hackberry-Pi_Zero – A handheld Linux terminal using Raspb... by teraflop on Friday August 02, 2024 @03:12PM (#41141688)
Yes, that is exactly what I said at the beginning of this thread.
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Re:Hackberry-Pi_Zero – A handheld Linux terminal using Raspb... by samstave on Friday August 02, 2024 @09:30PM (#41144049)
I asked the following above - does this work?

>> A mid-stream capacitor is holding enough charge for 10 seconds to allow indivdual swapping out -- and also this is meant? to mean that you can swap TWO NEW batteries in without having to shutdown/sleep/power interrupt - thus the 10 seconds.... that dope

EDIT: I was imagining the capacitor holds up the whole thing for ten seconds to swap out both bats...

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Re:Hackberry-Pi_Zero – A handheld Linux terminal using Raspb... by teraflop on Friday August 02, 2024 @09:51PM (#41144124)
In theory you could do that, but it has its own costs and complications. And if you're going to add a big enough capacitor to ride out a battery swap, why bother with two batteries instead of just one?
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Re:Hackberry-Pi_Zero – A handheld Linux terminal using Raspb... by numpad0 on Friday August 02, 2024 @10:49PM (#41144344)
Hotswap of two parallel batteries must replace both with a matched pair. Otherwise the one at higher state of charge starts charging others without current limit.
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