Re: Low Battery Warning Sign After Replacement?

On Aug 1, 11:53 pm, electronguy <electrosc...@xxxxxxxxx> wrote:
On Aug 1, 1:43 am, "DVHS.Stud...@xxxxxxxxx" <DVHS.Stud...@xxxxxxxxx>
wrote:

I've recently (3-4 days ago) replaced my batteries when the low
battery warning sign went on with Duracell rechargeable batteries
(fully recharged when I put them in).

However, now the low battery sign is on again. Are the batteries out
already or is it signaling the coin battery? How do I know which one
it is talking about? Should I recharge my batteries again (mabye
because they are new and this is the first time using them?)? Thanks.

A few questions come to mind, such as how much did you use your
calculator in the past three days, etc., but I'll try to offer a
couple of points.

If the 50g is like the 48GX, when the low battery indicator comes on,
if you turn your calculator off and then on while it still has the
battery low indicator, it should say something like "System Battery
Low" (likely not the exact text; I'm ready for bed and not going to
look up the AUR now--sorry) if the backup battery needs to be
replaced. Otherwise, I think it just responds with "Low Battery" for
the normal AAA batteries.

Like others have said, rechargable batteries typically have a lower
voltage (nominally rated at 1.2V whereas alkalines are nominally rated
at 1.5V). This means, for most purposes, that the batteries will
reach the depleted operating voltage earlier than alkalines.
Depending on current draw from the device being powered, however, one
may get good results from NiCads, etc., due to their low internal
resistance (where alkalines will have a larger voltage drop at higher
current loads when they start getting depleted). It's been my
experience with rechargable batteries that they usually indicate close
to full charge for a long time and then deplete quickly, whereas
alkalines tend to slowly fade away.

I tend to use a fair number of rechargable batteries and invested in a
Maha PowerEx MH-C9000 WizardOne Charger-Analyzer. It's likely
overkill for many, but it has battery breakin and refresh features
that are useful to me. Also, I can program each battery for the
charge and/or discharge current that I want, so I can taylor the
charger to the battery capacity. Moreover, what the analyzer portion
of the device shows is available capacity for each battery. There may
be a case where you have one battery that's not quite up to par with
the rest of the pack. By performing an analysis on a group of
batteries, one can properly match the capacities to get the most out
of the investment.

Lastly, I've switched to EneLoop batteries by GE/Sanyo. They
supposedly have a long-ish self discharge and (higher?) operating
voltage that approaches alkaline performance. I believe I've read
other threads in this group where low self-discharge NiMH batteries
have been discussed.

Unfortunately, the 50g dosen't seem to have provisions to adjust its
battery monitoring to account for the discharge pattern of rechargable
batteries (my GPS allows me to switch between various battery
chemstries, for example). Since the calculator is expecting a "slow-
ish" discharge from alkaline batteries, and given that most
rechargables deplete quickly, I tend to always keep a set of fresh
batteries with me for a quick change at the university. For finals
week, I use Lithium AA cells.

Regards,
Scott

Hmm okay, so I guess it is my 4 AAA batteries that need to be changed.
I haven't used my calculator that much at all for the past 2-3 days. I
would say only about 2-3 hours MAX. Should I recharged them and then
put them back in or what? Will this lower my battery life again?

.

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