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Old February 26th 16, 09:19 AM posted to uk.rec.audio
RJH[_4_]
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Posts: 214
Default Quad FM4 Battery

On 26/02/2016 07:02, Phil Allison wrote:
Johnny B Good wrote:


Quad list it as a 4V battery - quite how they achieve that is another
question altogether!



** Quad have " 4.8V NiCd " printed on the schem next to it.



It might be the charger's nominal upper voltage limit for a 3 cell NiCd
(blue) or 3 cell NiMH (green) battery. Constant current charging of
either type results in a 'resting voltage' immediately after going off
charge in the region of 1.4 volts per cell, usually dropping to 1.36
volts after a day or two. The 1.2 volts rating for these cells is the
minimum voltage just prior to becoming exhausted of useful charge.


** The rest voltage of a NiCd cell is 1.25V - under a moderate load it drops to 1.2v and is exhausted at 1.1V.

When trickle charged in memory back up use, there is just enough charge to compensate for internal self discharge - normally about C/50. So for a nominal 150mAh cell, that equates to a 3mA trickle charge.

A good condition, 4 cell pack ought to measure between 4.8 and 5V.


This one reads 4.6V.

I've been in touch with the seller. I've had a couple of messages. Last
week's was 'I'll sort it next week'. This week's is the same ;-)

It turns out that he hasn't (he says) used the tuner for some years.


--
Cheers, Rob