|Re: Will these batteries damage my HP 50g??|
Message #5 Posted by Les Wright on 12 May 2007, 6:13 p.m.,
in response to message #1 by PhysicsNerd
This is yet another good juncture for me to sing the praises of rechargeables in HP49 series.
I invested in set of 1000 mAh NiMH Duracells and quick charger for my 49G+. I also routinely and quickly back up my home directory and flag settings to an older SD card--at 128MB too small to be useful in many other devices, but positively huge as far as the 49G+ is concerned.
My 49G+ sat mostly unused for almost a year since I disliked to expense and waste of it gobbling alkaline batteries--certainly unlike anything I had ever encountered with my 48G. But recently, the HP49G+ has got routine and extensive use--so much so that the infamous and unpopular gold paint job (which I actually find strangely appealing) is beginning to wear and pit around the edges of the keyboard. Indeed, in recent weeks it has become my favourite calculator and I am spending more time trying to master UserRPL instead of more familiar RPN keystroke programming.
The old wisdom was that rechargeables were unsuitable for these calculators for fear that the would conk out without adequate warning and you would lose memory. But NiMHs are actually pretty good these days. And, at least in my 49G+, the back up wafer cell seems just fine to preserve memory while the batteries are out the 10 minutes it takes to recharge them.
In an examination setting you may want to carry a backup set of batteries with you in any case, no matter what kind of cells you use.
As for preserving your memory, this is certainly one of the areas where the 49 series tower over their older predecessors. The smaller SD cards have become so inexpensive these days that I think that there is no good reason for any serious user of the 49G+ or 50G not to have one in the calculator at all times. It is so quick to and straightforward to back up the HOME directory and flag settings that I have a little program to do it that I run out of habit several times the calculator is on and almost always just before a finish a session with it. Backing up the calculator state of the HP41 requires a card reader, 11 magnetic cards, a few minutes, adequate batteries, and plenty of concentration lest the cards get mixed up. And you can't even back up the memory of the much-celebrated 15C and 42S.