It's possible but we have to assume that the regular battery is ok as the
OP stated, and the battery doesn't have to be full charged for camera to
give some info.

Haven't reset the time in my camera in 8 years. Surprises me but the manual
says it will lose time after several days without power. Must have been
close several times. Don't remember ever seeing that before and I'm that
rare breed that actually reads the manual. The camcorder I do remember. It
just says you have a short amount of time. Inferring not much longer than it
takes to recharge the battery. So they must use capacitors.

It may be hard-wired into the camera with the expectation that the camera
will be out-dated by the time the battery wears out.

If that is the case, happy camera shopping.

But, you might want to look over the whole camera with a keen eye, looking
for anything that looks like a small sliding cover.  Sometimes, certain
details are missed during production of the manual.

If your budget will allow, you might want to look at a new unit.  My wife
and eye purchased a Canon A70 a few years ago for about $350, with a 3 meg
sensor.  The sensor chip recently stopped functioning, so we got a new
camera.

The new one, a Canon A720 (for $220), is an 8 meg unit with a better optical
zoom, better video capabilities, a nicer display panel, better white balance
detection, and a higher ISO range, just to name a few things.

Technology is moving quickly, and it's nice when you can play with the new
stuff.

Good Luck,
Dudley

    It may and should have some information, but the problem that most of us
don't realize its existing, and don't know where or what to look for.  And I
knew it because I read it many many years ago, and it happened to my film
camera once.

    Also, it uses battery similar to Hearing-Aid, Watch bettery (micro
battery)

If they are anything like camcorders then yes, they expect you to chuck
it when the internal battery dies. I have a Canon Mini DV camcorder from
a few years back. Every time I turn it on, even when plugged directly
into the AC adapter, it immediately asks me to to  set the date and
time. The internal battery died and nowhere in the documentation or on
Canon's website are there any instructions on how to change it or even
the fact that it exists.

And of course a competent repair place would charge many times the
camera's value to dig out the old battery and replace it. The value of
anything but high-end digital photo and video gear plummets faster than
a used Edsel when driven off the used car dealer's lot.

In the bad old days of CMOS batteries in computers they were soldered
onto the motherboard. I managed to exchange exactly one battery on an
old 386 notebook by unsoldering it and resoldering in a replacement
obtained from some obscure computer parts supplier. More recently
working on Macs I managed to get a copy of the Mac repair parts and
procedures CD (eBay is your friend) and since the batteries are no
longer soldered in place I have successfully replaced several
motherboard batteries.

The Canon mini DV is now relegated to stop-motion capture. I don't keep
a battery or tape in it; it is just a FireWire camera feeding directly
into my Mac. Because I don't depend on time code generated by the camera
I don't care what the date display is. Otherwise I would have
drip-kicked it long ago.

Remember, if the manufacturers didn't expect their products to be
disposable how would they ever sell the next "generation"?

--k

    Small screw driver YES, taking the camera apart NO.  And in the very first
message I pointed to you where it may be.