solved-New HP prime battery problem ??

[MathWizard]

solved

Yeah thanks for the firmware link, I'll have to see what mine is. So far the graphing utility is helping out, like graphing decaying sine waves for circuits. So far it is a lot easier to graph stuff in this than say Octave GNU. I'll have to check out the PC HP Prime version, sometimes that should be better to use than the calc. But yeah no regrets about buying this, I can far more easily compare LTspice sims to my calculated functions for once.

And it's very fast.


skip to bottom post...seems to be battery problem ?


I dabble a bit with GNU octave on PC, but I most of the math I do is on a scientific calc, or by hand. My calc can do 3rd degree polynomials, and 3x3 matrices, but only with real numbers.

I would like to be able to solve some higher order matrices w/ complex numbers, or find Eigenvectors, on a calc. It would be nice to solve some ODE's on a calc too, and plot stuff like that, without needing to learn code every time.

And what about tablet's, are they making super graphing calculator's the size of tablets ? Or can you get tablets that would run all the common PC programs ?

I'm just watching a few overview videos



IDK if LTSpice has an easy way to plot ideal models, or equations. But too often, IDK if my answers are off, or if the sim is just doing something more complicated than my equations. But I like how in LTSpice you can plot something and then drag cursors around. I hope I can do that in GNU octave too.

Whats a more user friendly math program, that does plots and solves ODE's, without needing so much coding ? I guess there's not that much to doing systems of 1st orders equations, I've done it before. But if I had a simpler program, that was more point and click, I'd use it.

Either way I should get a gfx calc., any recommendations ?

[alm]

In my opinions calculators are worth it for simpler tasks due to their dedicated keyboard, fast boot time and small size. Or if you're in school taking a test where no computer is allowed. But for anything more complicated I prefer to use a computer with a bigger screen. That's why no one makes calculators for engineers anymore.

I'm an RPN person, so I'd prefer the discontinued HP50g. Although I mostly use it for it's capabilities with units. For linear algebra I mostly use Python with Numpy and Scipy. I might look at the HP Prime if I really wanted a new graphical calculator.

There is a version of Octave for Android based on GNURoot. And there are tablets and convertible laptops that can run a desktop OS. I'm not sure if a graphical calculator is so much easier to use than Octave/Matlab once you go beyond typical high school problems. You won't have to program. Just type in text based commands. Not unlike how calculators work.

[MathWizard]

I'm impressed with the HP prime. I've never had a gfx calc. before, so I'll probably skip all the LCD models, as cheap as some of them are. But there's just no comparing to the big color screen, the speed, or what you can solve on them.

I never tried a RPN calc before, I don't think I've ever seen it mentioned or used in any book I've used. I need a new keyboard too, maybe then I'll use Octave more.


Years ago I think I used Maple or Matlab. Nowadays, don't they charge a yearly fee or something ? So GNU octave tho, is that a lesser polished looking, freeware version of Matlab ?

[HighVoltage]

I still use the old HP RPN calculators mainly the 11C or 15C.
Or for something quick to be programmed, the Sharp BASIC programmable PC's, mainly the PC1350 or the PC1600.

I never saw a need for a graphing calculator, a real PC is much faster for that or a quick visit at Wolfram Alpha gives a perfect first impression.

And I still have an older version of Maple installed (no yearly fees)

[aeberbach]

I bought the SwissMicros DM42 because I love the HP RPN machines. I use it most.

The HP Prime is one I bought before the SwissMicros and it's not really a RPN machine though it sorta kinda pretends to be if you want. It is the easiest for matrix calculations and overall is a great calculator, even the keyboard is not bad. A screen protector is vital as the plastic is very soft and will scratch if you put _paper_ on it.

The Ti NSpire CX II that my kids have for school is an abomination and I hate them. I don't want to see Microsoft Excel that often.

But for graphing calculators none of them are anywhere near as good as just about any device that can access a web browser, phone included. Are you ever that far from such a device?

[PartialDischarge]

I have the HP prime an I regret its purchase, should have bought and older HP48G or similar.
The thing doesn't even have an UNDO button which is a must to manage a stack of numbers in RPN.
Also it doesn't have a way to fast SWAP the last 2 items in the stack (1 key in the HP48).

Yes it has color and potent maths but don't use it for that...

[MathWizard]

The HP prime is barely available anymore (in Canada), and I don't want to pay over $220US. I tried to buy it this morning at a better price, but the amazon seller doesn't ship here. And I don't want a used 1 with a worn out battery. I could get the TI spire right now, but yeah I'm hesitant over some things.
 
IDK anyone with a TI spire to try it. I'm usually at my PC when at math, but I would still like the ease of using something in my hands right next to the paper.

I should look up what math some of the older models do. The battery life of the old LCD's would be nice too.

[IanB]

IDK anyone with a TI spire to try it. I'm usually at my PC when at math, but I would still like the ease of using something in my hands right next to the paper.

I honestly would have thought the best answer for this would be a tablet running a suitable app (or apps)? The compute power, screen quality and app functionality would seem to far exceed anything you can get on a calculator. Even the best calculator is going to be ancient, slow and primitive compared to a computer app.

[MathWizard]

Well I ordered the HP Prime G2. It should be great, and it has CAS. There's certain eqn's I should never waste time on again, I've already done them 50k times on paper.

A calc like this will be great for if I go to the library, or take it to work too. But yeah I'm still have to learn a bunch more buttons/etc. But for now that'll be easier than really digging into Octave.

[zrq]

I like my HP Prime G2 s, both physical and simulated on Windows and Android. They saved me a great amount of time for quick and dirty math, before I bother to fire up MATLAB or Mathematica.

I used the earliest generation nspire CAS when I was in high school and undergrad. I enjoyed it but I would say I'll pick HP Prime if I got a choice back then. Nspire's document based interface is too much designed for learners.

Unfortunately, HP Prime's development seems to be abandoned, 14603 will likely be the last firmware release. (Please, please, prove that I'm wrong.)

[Bicurico]

The HP Prime is a great calculator, no doubt.
But somehow I never liked to use it, not really sure why.
My all-time favourite was the HP48GX. But don't spend money getting a second hand unit. Mine broke due keyboard failure, a common problem which is basically impossible to repair.
I have the HP50G, too. It is a good replacement for the 48.
My recommendation for OP is to just use any comfortable calculator for small calculations and Wolfram Alpha for anything more complex.
If you really want to dive into heavy maths, see if you have access to MATLAB or similar, i.e. if you are a teacher or student. But mind you, there is quite a steep learning curve associated.
I do most my math using Windows calculator out of convenience, Excel or sometimes I just program in VB.net to get the results I need.
There is no calculator that does all you want out of the box and most top of the range models are just developed for Uni. This means they are crippled to avoid cheating.
Regards,
Vitor

[tooki]

The HP Prime is one I bought before the SwissMicros and it's not really a RPN machine though it sorta kinda pretends to be if you want. It is the easiest for matrix calculations and overall is a great calculator, even the keyboard is not bad. A screen protector is vital as the plastic is very soft and will scratch if you put _paper_ on it.

LOL what? Did you forget to remove the plastic screen protector, and thought that is the screen? Because the HP Prime’s screen is hardened glass. I’ve had mine for over 2 years and it has not a single scratch. (And according to the Prime’s hardware designer, the screen glass has proven more durable than they’d hoped!) Are you sure you weren’t seeing “scratches” in the skin oils deposited onto the screen, as others in that thread reported?

[tooki]

Unfortunately, HP Prime's development seems to be abandoned, 14603 will likely be the last firmware release. (Please, please, prove that I'm wrong.)

New firmware was released on 2023-04-24: https://www.hpmuseum.org/forum/thread-19845.html

The development of HP calculators was transferred to a different company (which has been a partner for decades already), and that company is now starting to release updates.

Here is a presentation explaining it: https://youtube.com/watch?v=QLTzr1-ztgk

[tooki]

IDK anyone with a TI spire to try it. I'm usually at my PC when at math, but I would still like the ease of using something in my hands right next to the paper.

I honestly would have thought the best answer for this would be a tablet running a suitable app (or apps)? The compute power, screen quality and app functionality would seem to far exceed anything you can get on a calculator. Even the best calculator is going to be ancient, slow and primitive compared to a computer app.

1. Real keypad. Touchscreens suck to type on in comparison.
2. Instantly ready to use.

3. You have evidently not tried the HP Prime: it is neither ancient, primitive, nor slow. (It’s got a 528MHz ARM CPU that easily keeps up with everything.) It’s got a capacitive touchscreen that works really well alongside the nice tactile keypad. The screen’s picture quality could be better, but it is by no means bad.

[tooki]

Well I ordered the HP Prime G2. It should be great, and it has CAS. There's certain eqn's I should never waste time on again, I've already done them 50k times on paper.

A calc like this will be great for if I go to the library, or take it to work too. But yeah I'm still have to learn a bunch more buttons/etc. But for now that'll be easier than really digging into Octave.

I think you’ll like it. I have come to love mine.

[MathWizard]

Well it finally arrived, I got it new from ebay, in a sealed package that looked factory legit. And after removing the plastic blocking the battery contacts, it turned on, then it said to charge the battery. So I plugged it into a USB3.0 port, and left it overnight. All I saw indicating it was charging, was just a tiny lightning bolt in the top right corner, over I guess the battery symbol which looked about 75% already when I got it.

Then this morning, the PC makes the noise for when you unplug a USB device, and the calc would not turn on at all. I reset it and still nothing. I checked the battery, it's only at 2.98V. It was room temperature tho, so at least not about to catch fire.


I plugged back in, and got it to turn on again. But with it unplugged, the battery symbol has a red ! mark over it. And the calc says the battery is critically low, and to plug it in.

So has the the 3.7V Li+ battery basically worn out on the shelf ??

[Bicurico]

It probably doesn't charge using a PC USB port. Try to connect a phone charger.

[tooki]

That is very odd. Charging from a PC is expressly supported, according to the manual.

All the same, I would try a phone charger.

[MathWizard]

I just left it plugged into the PC for about 1 hour, like before, the screen stayed on the whole time. But now I come back to it, and it's shut down again, and won't turn on. The voltage is only 2.975V, after ~1 hour

I have a z690 mobo, I apparently didn't use the lightning USB3.2 port, I'll try it. I don't have any modern phone charger.


No I can't do that, they gave me 2 cables, 1 is regular USB, IDK what the other is, but neither is USB-C like the lightning port.


I tried another USB port, and it still didn't turn on, but it did when I connected to the USB port on my DMM. But I'm guessing that's for even lower currents than the mobo.

So I now plugged it into a cheap 5V wallwart, rated for 1A. But I still can;t say if it's really charging, besides that little lighting bolt symbol.

[MathWizard]

Ok now after just a few minutes, the battery reads 3.7V, so I guess my MSI z690pro mobo just won't do the current required for charging.

So I better get a good quality charger, not the generic one I just used.

[tooki]

The reason for using a “dumb” charger is to avoid the need for power negotiation. That matters mostly when a device’s battery is so low that it can’t power up enough to perform the negotiation! (Classic example: some USB iPods. Using a dumb charger was often necessary to recover from an extremely discharged battery.)

Bear in mind that 2.9V might be right around the battery charger’s ”precharge” threshold, below which it will first charge very slowly, to prevent cell damage. Once it’s above the precharge voltage, it’ll revert to full-speed charging.

I’d give it a few hours to charge. Bear in mind that the peak voltage of a 3.7V cell while charging is around 4.2V, which of course will drop a small amount once removed from the charger. Just don’t think that 3.7V is anywhere near fully charged.

FYI, the Prime’s battery indicator is very imprecise, showing only 25% steps. But as long as you charge it once it starts yelling at you, you’ll be fine. Battery life hasn’t been any kind of problem in practice.

[aeberbach]

The HP Prime is one I bought before the SwissMicros and it's not really a RPN machine though it sorta kinda pretends to be if you want. It is the easiest for matrix calculations and overall is a great calculator, even the keyboard is not bad. A screen protector is vital as the plastic is very soft and will scratch if you put _paper_ on it.

LOL what? Did you forget to remove the plastic screen protector, and thought that is the screen? Because the HP Prime’s screen is hardened glass. I’ve had mine for over 2 years and it has not a single scratch. (And according to the Prime’s hardware designer, the screen glass has proven more durable than they’d hoped!) Are you sure you weren’t seeing “scratches” in the skin oils deposited onto the screen, as others in that thread reported?

Mine doesn't look like glass - and I don't think I will peel off the screen protector to check how hard it is! It's a G2, could the earlier revision have had glass while this is plastic (or the other way round)? Either way I covered it and will leave it covered.

[tooki]

Nope. Everything I’ve ever seen says it’s hardened glass. I have the G2 and it’s definitely glass, but old discussions from the G1 days also say it’s glass.

One easy way to tell: chill the device a bit. Glass will feel much colder than plastic.

[MathWizard]

solved

Yeah thanks for the firmware link, I'll have to see what mine is. So far the graphing utility is helping out, like graphing decaying sine waves for circuits. So far it is a lot easier to graph stuff in this than say Octave GNU. I'll have to check out the PC HP Prime version, sometimes that should be better to use than the calc. But yeah no regrets about buying this, I can far more easily compare LTspice sims to my calculated functions for once.

And it's very fast.

[tooki]

Any updates on the charging situation?