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USB batteries
08-08-2023, 12:44 PM
Post: #1
USB batteries

just a quick report about using "USB batteries" in vintage HP calculators. Some time ago I was given an assortment of these batteries by my son who saw them in a museum shop. Now they can be found almost everywhere at very interesting prices (like on Amazon, eBay or Aliexpress. I don't provide links because these tend to be very shortlived). I have seen them in sizes AA, AAA and 9V block and they have the exact same voltage of the originals, but inside they contain a rechargeable lithium cell and some electronics. They have a small USB socket are are recharged from any 5V USB supply through a standard cable.

So far I have tried them in woodstocks, classics and an HP-71B and they work just fine. I have had a couple inside a 29C for over three months now and there is no noticeable self-discharge. I don't know what will happen if one connects a device contiaining these cells to a charger because they are not supposed to be charged through their normal connectors, but I guess that they have some sort of protection.

As far as I am concernded I will never buy a disposable battery ever again.

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Messages In This Thread
USB batteries - Maximilian Hohmann - 08-08-2023 12:44 PM
RE: USB batteries - Jeff_Birt - 08-08-2023, 12:55 PM
RE: USB batteries - blackjetrock - 08-08-2023, 01:50 PM
RE: USB batteries - aurelio - 08-08-2023, 02:38 PM
RE: USB batteries - rprosperi - 08-08-2023, 04:46 PM
RE: USB batteries - aurelio - 08-08-2023, 05:18 PM
AA rechargeable with USB-A - striegel - 08-11-2023, 07:05 PM

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