On Tue, 30 Oct 2012 08:17:26 -0500, Mark Lloyd
wrote:

On 10/30/2012 05:12 AM, Michael wrote:
I have two clock/radio television units. Both have battery backups.
I installed fresh 9 volt batteries and when power was restored last
night after a 3 hour outage, the clocks were 8-10 minutes fast. What
gives? I thought the batteries were supposed to maintain the time.
Just curious.


Plug-in clocks with battery backup usually seem to use a cheap RC
timebase when on battery. They're not very good at timekeeping during
power failures. Most I have are accurate on AC, fast on battery.

What others have said. In addition, fast is intentional for alarm
clocks because fast is better than slow when the goal to make sure you
get up on time.