Re: Timemaster clock battery

["Michael J. Mahon" <mjmahon@aol.com>]

On 8/2/2010 9:12 AM, Scott Alfter wrote:
> In article<d80b27d9-0931-4f1d-b1f1-708ad95b5233@w31g2000yqb.googlegroups.com>,
> drkenb<kbuchholz1107@hotmail.com>  wrote:
> > I've not found any info indicating that NiMH will not work correctly -
> > where have you found that information?
>
> A charging circuit designed for NiCd won't properly charge NiMH batteries,
> and vice versa.  Standalone chargers that handle both types are pretty
> common now, but the Timemaster predates NiMH batteries by more than a few
> years.
>
> A while back, I picked up a Bluetooth mouse that charges its NiCd AAAs when
> it's plugged into a USB port.  When those batteries quit holding much of a
> charge, I tried replacing them with NiMH batteries.  The built-in charger
> won't charge them properly, so I ended up packing a separate charger with my
> notebook stuff.

However, since the charging circuit in all these clock cards is a simple
float or "trickle" charger operating at very low current (typically a
milliampere or two), there is no incompatibility.

A fast charger (less than 20 hours) will need adaptation to the battery
chemistry, but a trickle charger does not.  (Lithium ion is a special
case!)

-michael

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