Duracell DC2400B4N Rechargeable Batteries, NiMH, AAA Size for Hp 50g?



#14

Will Duracell DC2400B4N Rechargeable Batteries, NiMH, AAA Size work well for my HP 50g?

Also, I've came across this thread: http://groups-beta.google.com/group/comp.sys.hp48/browse_frm/thread/96e4695744e66f37/920cf
0b84ab84d3c?lnk=gst&q=Re%3A+4+batteries+vs.+3+batteries&rnum=1#920cf0b84ab84d3c

Someone on there said that replacing batteries when the low battery indicator comes on will cause the calculator to have a shorter battery life span. Is this true? If so, should I just change it when the batteries are dead? Will there be any negative affects on doing this (memory wiped out)?


#15

Hi 'Nerd--

I use 1000mAh Duracells in my 49G+ and love it. I monitor the level (roughly) with Cordoba's BatStatus. I have a quick charger and give them a rejuice when LowBat warning appears. Indeed, with NiMH's the window between LowBat and "dead" is brief.

The coin battery should preserve your memory for awhile, but better yet, maybe you should plug the 50G into the USB power option to preserve memory while you rejuice the batteries. Better yet, do regular backups of your HOME directory and flags to an SD card using the commands intended for the purpose (RCLF, STOF, ARCHIVE). I have a little applet that does that and thus back up obsessively.

Maybe NiMH battery life is diminished between rechargings, but I don't care. Anything is better than gobbling up all those alkalines. The 49G+ actually gets used now!

Finally, and I know you have been concerned about this before, a fully juiced set of NiMH's is more than enough to get you through an exam.

hth,

Les


#16

I do not know why, but after I've replaced the old batteries with the new rechargeable ones, the low battery sign is still on? Is this some kind of error or do I have to replace the coin battery?

Btw, the batteries I've put in place of the old ones are brand new rechargeables.


Edited: 26 July 2007, 12:13 a.m.


#17

Does anyone know if BatStatus will give interpretable readings on the 50G? If so, it could help you (look for it at hpcalc.org--it is a very tiny program and easy to run).

I don't want to insult your intelligence, but did you give the NiMHs a full charge before you put them in? If so, you may wish to drain them down and charge again--I understand it may take a few charge/discharge cycles to maximize capacity.

Les


#18

Quote:
Does anyone know if BatStatus will give interpretable readings on the 50G? If so, it could help you (look for it at hpcalc.org--it is a very tiny program and easy to run).

I don't want to insult your intelligence, but did you give the NiMHs a full charge before you put them in? If so, you may wish to drain them down and charge again--I understand it may take a few charge/discharge cycles to maximize capacity.

Les


You did not insult my intelligence in any way. In fact, I never knew that they are not fully charged when taken out of the package. lol Thanks guys, I'll charge them now and see if it works later.

#19

Quote:
Does anyone know if BatStatus will give interpretable readings on the 50G? If so, it could help you (look for it at hpcalc.org--it is a very tiny program and easy to run).

Yes, but for some information on improving the constants for use on a 50g, and having the program check which model it's running on, see this comp.sys.hp48 thread.

Maybe also check out other threads found by http://groups.google.com/groups/search?q=BatStatus+group:comp.sys.hp48.

If you're going to always use rechargeables instead of alkalines, then it may be useful to add another tweak so that a fully-charged battery shows 100%.

I should note that the "percentage remaining" seems to assume that the voltage to energy stored ratio is linear over the operating range, which isn't quite true.

GaaK is supposed to have a 49g+/50g BatStatus library available on his web site, but at the moment, it seems that his bandwidth limit has been reached; maybe wait for it to show up on hpcalc.org.

Regards,
James

Edited: 28 July 2007, 2:45 a.m.

#20

Have you actually charged the "new" rechargable batteries?

Rechargable batteries do not come with much residual charge (they loose it through self discharge in a few months), unless you get the new technology Eneloop brand.

Dave.


#21

Quote:
Have you actually charged the "new" rechargable batteries?

Rechargable batteries do not come with much residual charge (they loose it through self discharge in a few months), unless you get the new technology Eneloop brand.

Dave.


Okay, I've charged the batteries and put them back in and now the low battery sign is gone. However, my text has reverted to default. Is this a memory erase? I've had this happen to me 2 times already when changing batteries. Why does this happen and how can I prevent it from doing so? Thanks again in advance.


#22

On my 49G+ at any rate, putting batteries in after they are out seems to activate a soft reset, as though you hit ON+C

If I change my stack font to the 6 pt system font, then take out the batteries then put them back in, the stack font is restored to default 8 pt font.

This happens too when I do ON+C.

My variables are NOT deleted. This is not memory erasure.

I don't know how to prevent this resetting of the stack font size. I don't think display font is controlled by flag settings you can save then restore. Maybe someone else knows?

Edited: 26 July 2007, 4:19 a.m.


#23

Quote:
On my 49G+ at any rate, putting batteries in after they are out seems to activate a soft reset, as though you hit ON+C

If I change my stack font to the 6 pt system font, then take out the batteries then put them back in, the stack font is restored to default 8 pt font.

This happens too when I do ON+C.

My variables are NOT deleted. This is not memory erasure.

I don't know how to prevent this resetting of the stack font size. I don't think display font is controlled by flag settings you can save then restore. Maybe someone else knows?



Also, note only does my font reset back to the default one, but the TIMEKEY rate changes also. I have to type ->TIMEKEY(500) to change the rate of the buttons back to fast.

#24

Quote:
On my 49G+ at any rate, putting batteries in after they are out seems to activate a soft reset, as though you hit ON+C

For me, this seems to happen only if I remove the battery while the calculator is turned on, or I press the ON key while the battery is removed. I'm not certain, but it might also occur if the battery is left out for more than a couple of minutes.

Quote:
If I change my stack font to the 6 pt system font, then take out the batteries then put them back in, the stack font is restored to default 8 pt font.

This happens too when I do ON+C.

My variables are NOT deleted. This is not memory erasure.


Quite so; it's what's usually known as a "warmstart", sometimes called a "system halt". Of course, if left without power (including from the CR2032 cell) indefinitely, then it will eventually lose the RAM contents, so a TTRM (Try To Recover Memory?) would occur when power is restored.

Quote:
I don't know how to prevent this resetting of the stack font size. I don't think display font is controlled by flag settings you can save then restore. Maybe someone else knows?

Flag -72 controls whether the current font or the mini font is used for the stack. Of course you can use the \->FONT command to set the "current font" to any built-in or user-defined font.

If you store a program in the reserved variable STARTUP, then it will be run at the end of every warmstart, and it can be useful for restoring your preferred modes and attaching/detaching libraries.

To prevent STARTUP and any library configuration routines from being run, hold down the backspace key while warmstarting.

Regards,
James

Edited: 28 July 2007, 1:26 a.m.


#25

Hey 'Nerd, did you catch that?

I actually had totally forgotten about the STARTUP variable--I never use it.

Les

#26

Quote:

Flag -72 controls whether the current font or the mini font is used for the stack. Of course you can use the \->FONT command to set the "current font" to any built-in or user-defined font.

If you store a program in the reserved variable STARTUP, then it will be run at the end of every warmstart, and it can be useful for restoring your preferred modes and attaching/detaching libraries.

To prevent STARTUP and any library configuration routines from being run, hold down the backspace key while warmstarting.

Regards,
James



I have no idea what you are taking about. This calculator is VERY complicated to use and I'm not familiar with how things are stored. I do know where the STARTUP variable is, I do not see it when I browse through the files of VAR. How long does it take you to get used to this calculator and be able to transfered files, etc.?


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