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Subject: Re: FM Recorder battery levels
From: Mike Holden (
Date: 2003-02-06

>> As I mentioned in another post, I believe the basic battery levels on
>> the FM Recorder model are being read wrong. The current values show a
>> scale from 4 volts downwards, but surely, despite the new battery
>> type, it is still 4 x 1.5 volt batteries, for a maximum of 6 volts?
>> The harddrive still needs 5V, yes?
> Li-Ion batteries scale from a max of 4.2 under charge to the ~3.5 when
> flat. This pdf gives you a good overview on the tech
> verview.pdf
> There are either two cells (= 7.2V nominal, but from what I have read I
> dont think there are), or the FM has a step up to power the HDD.

Informative PDF there - not sure I follow the chemistry etc though!

Seems like a nominal 4volts is about right then. It just seemed strange to
me that a 5v disk could be powered from a 4v battery.

Star Trek technology here we come!

Mike Holden

Page was last modified "Jan 10 2012" The Rockbox Crew