48GX, TDS RAM Card, Low Batt Indicator

[Ron G.]

When the TDS RAM card is put in the 48GX, the calculator indicates a low batter on the card (low batt P2). This is a card without a battery. The extra memory shows up on the calc, as expected.

Tried another to-battery TDS card, and there was no low batt indication. Can someone explain this to me? Many thanks.

[James M. Prange (Michigan)]

Does it still show the low battery indicator with the card removed?

Do you mean a ROM card by any chance? If so, then maybe try a warmstart by holding down the ON key, pressing and releasing the C key, and finally releasing the ON key. If that doesn't help, you could try archiving user memory, then doing a user memory clear by holding down the ON key, pressing the A and F keys, then releasing first the F key, then the A key, and finally the ON key, and then pressing the NO menu key in response to the "Try To Recovery Memory?" message.

All RAM cards do have a battery, but I seem to recall that some cards use a non-replaceable battery, intended to last for the "life of the product". In other words, if you can't replace the battery in your RAM card, then it's lifetime is over.

Regards,
James

[Randy]

Quote:

---

In other words, if you can't replace the battery in your RAM card, then it's lifetime is over.

---

Not an accurate statement...

The later TDS and SMI cards that have internal batteries are charged by the GX when it is powered on.

Let your GX sit for a month or two without turning it on and you'll have the exact situation you just described.

The details from the TDS website:
HP48GX Memory card info

Edited: 15 July 2007, 10:52 a.m.

[Ron G.]

Thank you. That's the information I needed.

[James M. Prange (Michigan)]

Thanks for the correction, and the link to the relevant TDS page.

It seems that the card's lifetime isn't really over until its rechargeable battery fails to take a charge.

Quote:

---

The later TDS and SMI cards that have internal batteries are charged by the GX when it is powered on.

Let your GX sit for a month or two without turning it on and you'll have the exact situation you just described.

---

And I expect that the same would happen if the card were removed for a month or two.

Does anyone know which type of rechargeable battery is used in these cards?

TDS's method of setting a repeating alarm to keep the calculator turned on is good, but I'd add that it would be better to use a "control alarm" (such as the program \<< DROP \>> for the "message" instead of a character string) instead of an "appointment alarm", so that it doesn't sound the beeper. Also, since the automatic turn-off on the 48 series seems to be 10 minutes, I'd set up the alarm to repeat every 599 seconds instead of every 299 seconds. One could also add a control alarm to delete the repeating alarm after 24 hours. I'd prefer to try running this recharging procedure starting with fully-charged NiMH AAA cells.

Regards,
James

Edited: 16 July 2007, 3:05 a.m.

[James M. Prange (Michigan)]

PS:

I wrote:

Quote:

---

... it would be better to use a "control alarm" (such as the program \<< DROP \>> for the "message" instead of a character string) instead of an "appointment alarm", so that it doesn't sound the beeper.

---

Better yet, go ahead and use an appointment alarm (any character string for the message), but set flag -57 (Alarm beep off). Flag -43 should be clear (Reschedule alarm), the default state, so that the unacknowledged repeat appointment alarms will actually be repeated.

Regards,
James