|WP-34S: Battery Level - some questions|
Message #1 Posted by Marcel Samek on 15 Sept 2013, 11:03 a.m.
I was fooling around with benchmarking different operations on the WP-34S and ran into some problems:
1) The timings were fluctuating significantly. I was using the ticks function and have a working crystal, so this was surprising. I set the fast mode but it had no perceivable effect.
2) Occasionally, the calculator would just turn itself off in the midst of running the benchmark loop. There seemed no rhyme or reason to it.
I suspected the battery level, but it was showing 2.9 whenever I checked it.
Because I was using the tick function to terminate the test after a certain time, I was not watching the calculator closely during the tests, but when I started noticing these issues, I started watching and realized that during the test, the battery annunciator would flicker on and off. Only during running the benchmark loop - it was never on otherwise. This confirmed my suspicion that it could be the batteries. I checked the level repeatedly, in between every loop, but it was a rock solid 2.9
So, I removed the batteries and clipped on an external battery pack with two new D cells. And started rerunning the tests.
Now, not only were the results very consistent, but they were also much faster between 30% and 70% faster, depending on the test. The calculator never turned itself off.
So, I guess the issue was my batteries, but this led me to some questions:
1) The level never showed less than 2.9 when I tested it. Yet, when running the program the battery annunciator would flicker on and off. I assume that means that the level was dropping below some threshold during execution. What is that threshold and is it normal for the voltage to drop that significantly while executing?
2) How accurate is the level indicator?
3) Is there anyway of telling if the calculator is executing in fast or slow mode because of battery level?
4) When the calculator turns itself off during execution of a program - could that be because of a voltage level (even though when I turned it back on the level showed as 2.9 again). What is that threshold? Is there any value left in memory that would indicate why the calculator turned itself off?