Hp prime lose date&hour when i change battery

[pippocalo]

As in subject if i change battery i must re-insert date & time in HP.
Why?
My program and data ara all OK.
Some can give an answer?

Thanks

Filippo

[eried]

Why do you change the battery? Probably the prime does not has a cap for keeping the rtc running while the battery in not in place... Like phones or tablets.

[toml_12953]

(01-26-2020 10:50 PM)pippocalo Wrote:  As in subject if i change battery i must re-insert date & time in HP.
Why?
My program and data ara all OK.
Some can give an answer?

Thanks

Filippo

Why are you changing the battery? The one that came with it is rechargeable hundreds, if not thousands of times. I've never needed to replace the battery on my Hardware A machine even though its years old. Just leave the calculator plugged into a USB power source or computer for a few hours and you're good to go.

[Tim Wessman]

Hopefully, it is just a spare battery they are changing to and not disposing of it.... :?

Yes, there is not anything to maintain the clock when the battery is removed. It really is not meant to change batteries (hence the screws in the battery lid cover). Also, any time the connectivity kit is on and you plug in, the time and date will be automatically set for you.

If longer power life is a concern, I recommend a small usb cable (20-30cm or less) and a small USB power brick.

[cyrille de brébisson]

Hello,

The real time clock needs power to work. No power means lost time...

However, the RTC uses VERY little power, and I have been successful in changing the battery without loosing the RTC, but 2 conditions needs to be meet to do so.
1) you need to minimize the power use of the calculator. To do so, place the calculator in deep sleep (press and hold the shift key, press the ON key, release the ON key and the shift key). This will kill power to ALL systems (including the RAM), except the RTC..
2) change the battery quickly.

Cyrille

[pippocalo]

thank you all for the comprehensive answers.
Indeed the explanation that RTC stops is very reasonable and I was stupid not to think about it.
In fact, if you connect the cable to the PC, the update of the date-time is automatic.
Thanks to Cyrille for her makeup.
I change the battery because my HP Prime is on for a long time every day; I bought a spare battery and I change it every month to consume them in a similar way, even i know that the li-ion batteries also kept in the drawer after 3-4 years are at the end of their life. But to me with a charge every 2 days they would last less if consumed one at a time. Alternating them, I have reasonable certainty that they will last 4-5 years.
For the future, it scares me to find "fresh built" batteries. Cellphones disappear, HP Calculators become cult objectss. I still have an HP 67 that works very well with 3 AA Ni-Mh batteries. In 10 years there will still be batteries for the HP-Prime ??

Thanks

Filippo

[CyberAngel]

(01-27-2020 09:10 AM)pippocalo Wrote:  thank you all for the comprehensive answers.
Indeed the explanation that RTC stops is very reasonable and I was stupid not to think about it.
In fact, if you connect the cable to the PC, the update of the date-time is automatic.
Thanks to Cyrille for her makeup.
I change the battery because my HP Prime is on for a long time every day; I bought a spare battery and I change it every month to consume them in a similar way, even i know that the li-ion batteries also kept in the drawer after 3-4 years are at the end of their life. But to me with a charge every 2 days they would last less if consumed one at a time. Alternating them, I have reasonable certainty that they will last 4-5 years.
For the future, it scares me to find "fresh built" batteries. Cellphones disappear, HP Calculators become cult objectss. I still have an HP 67 that works very well with 3 AA Ni-Mh batteries. In 10 years there will still be batteries for the HP-Prime ??

Thanks

Filippo

I understand that you want to still use the HP Prime G1/G2 for nostalgia reason.
That ancient hardware has already been replaced by then
Remember HP-65, HP-67 then the superior HP-41C/CV/CX
Jump to HP-48SX/GX, HP 49G then the historic hp 50g (*)
Now Prime G1/G2 - but -
technology advances and soon they (HP Team) need a new mobo & ARM
if not a new calculatrice system altogether (it could be in a design phase).
VPN
PS: I still use my (*) hp 50g

[eried]

I think what you are doing is just overkill and unnecessary, you might end wearing the screw threads on the plastic rather than keeping the battery healthy. My prime has a 6+ year old battery and still works perfectly.

Also, interest will drive hacks, so if enough people need Prime batteries in the future, there will be alternatives. You can even use AAAs https://www.thingiverse.com/thing:237922