HP 15C CE ships with mediocre batteries

[RPNerd]

TL;DR - If you buy a 15C CE, the very first thing you should do with it is toss the batteries and install some good ones.

Longer version: I bought a 15C CE a few months back, decided that I liked it so much that I went and bought another one (both units from a stockist here in the UK) and also ordered the 16C overlay and a few other things from TCS.

The first thing I did with the second unit was to update the firmware to eliminate some of the 16C bugs, then I toggled it into 16C mode, used it for a couple of days and then put it away for about a week until I needed it again. At that point in time it was unresponsive and I needed to prod the reset button behind the battery door (mumble mumble damn screw mumble mumble). We're back in business. Temporarily. The next day it was unresponsive again.

Thinking initially that this might be a bug related to 16C mode I put the machine back in 15C mode and it froze again almost immediately, so the next thing I tried was replacing the batteries. This fixed everything.

I think we all know that CR2032 lithium batteries fall into either of two categories. They are either from an established brand that supplies quality batteries like Energizer, Panasonic, GP, Maxell, Duracell (I've never had a lithium battery of theirs leak. Alkalines on the other hand...) etc. or they are from some unknown (usually) Chinese brand that produces batteries with huge internal resistance, low capacity and no shelf life. Unfortunately, it looks like the batteries that HP loads into new HP 15C CE units fall into the second category if they fail in a unit that's barely a couple of weeks old.

Do yourselves a favour. Before you start accumulating data that you might want to hold onto in your 15C CE units, yank out those cheap batteries and throw something better in instead.

[Divasson]

Also, the dynamic current consumption is high and the internal battery resistance is high too - so voltage falls a lot during program run while it stays at good levels on standby: the low power detector is not triggered. You may get unexpected errors and memory corruption when running programs - then that's the moment to change batteries (you can expect close to 1 year of normal use anyway)

A good back-up gives peace of mind - entering long programs is very cumbersome! You don't need to update it often.

[RPNerd]

(11-25-2024 04:31 PM)Divasson Wrote:  Also, the dynamic current consumption is high and the internal battery resistance is high too - so voltage falls a lot during program run while it stays at good levels on standby

...which it's why it's a good idea to make sure you're using good batteries with an internal resistance as low as possible! My background is in electronics and I've spent many a year trying to explain this to people both online and offline. I just find that this device is a lot more sensitive to the quality of the batteries used than most, especially if a unit is failing because of the batteries this early on in its life and while sitting in a drawer on standby.

Edit: Having said that, it's probably the surge when powering up that was causing the unit to crash, although that doesn't explain why it crashed while already switched on and sitting doing nothing.

[AnnoyedOne]

Related

https://www.hpmuseum.org/forum/thread-22574.html

A1

[RPNerd]

(11-25-2024 05:33 PM)AnnoyedOne Wrote:  Related

https://www.hpmuseum.org/forum/thread-22574.html

True. Once the batteries are getting depleted, any surge of current is going to make their output voltage drop and it'll create all kinds of havoc. I just didn't expect it on a device that was only a couple of weeks old and hadn't been used intensively at all in that time.

Of course, I suppose it's possible that this specific unit had been sitting on a shelf for months on end before being shipped off to me. I do wish the batteries were not included or that they were either wrapped separately or in place but with some kind of insulating tab to pull out before first use. Either solution would make sure they don't run flat while sitting in the warehouse.

[Johnh]

When the calculators are bought, the batteries are in and therefore supplying current on standby since they were assembled. The first hp15c-ce's are now about 18 months old, and maybe some from early batches are still up for sale. So if any doubt, new batteries from a good brand seem like the first thing to do. And get the firmware updated if it's not the latest and get YoyagerSave working. Then you can relax and the battlers should last a decent time, with nothing to lose when they finally run out.

[AnnoyedOne]

(11-25-2024 06:56 PM)Johnh Wrote:  Then you can relax and the battlers should last a decent time, with nothing to lose when they finally run out.

For the most part true.

That said you probably want to keep new batteries on-hand wherever you are plus a programming cable or you may have to "go without" until you can restore stuff later.

So, if you use your HP-15C CE at work, during travel, etc and programs/data are important to you take note.

Unlike most modern electronic devices, with the HP-15C CE, dead batteries = data loss.

A1

[Divasson]

Yes, but let's not forget that with decent batteries and normal use one should not be concerned for at least 10 months. It took 14 months to change the original set for me! You don't need to take the cable with you to the bathroom - there is some slack.

Another thing is if we succeed to create nice program sets - and then it makes sense to be able to load software pacs as needed.

[RPNerd]

(11-25-2024 09:31 PM)Divasson Wrote:  Yes, but let's not forget that with decent batteries and normal use one should not be concerned for at least 10 months.

Agreed 100% and that's kind of my point. I don't think the batteries that come with a new HP 15C CE are decent batteries, hence my recommendation in the first post of this topic.

(11-25-2024 09:31 PM)Divasson Wrote:  It took 14 months to change the original set for me!

Sadly, it took 14 days for me, most of which were spent in a drawer!

[rprosperi]

Regarding the title of this thread, it is not correct that the 15c CE is overly sensitive to battery quality, all modern devices with similar ARM processors (SwissMicros models, PX-41CX, earlier emulation devices) all have similar 'sensitivity' due to relatively high current draw when these CPUs are executing flat-out at top speed, which quickly pulls down the voltage of cheaply made, or mostly depleted cells. These CPUs use 10's to 100's of times the power the old Nut processors (and similar vintage) used, which is why we see the kinds of issues being reported, as compared to years or even decades-long battery life in the original Voyagers.

The best solution is to use high quality brands of newly purchased cells (to the extent possible) and though there seems to be great joy for many to write programs that will run for 10, 20, or 30 minutes or more on these machines, doing so will simply consume even a top-quality cell in no time. If such experiments are somehow satisfying, I'd say fine, so that, but have a good stock of cells on-hand, or in the case of the DM42, DM41X, DM42n or DM32, leave the USB connected to power the device (and as a bonus, you get much higher speed operation).

[Jase]

(11-26-2024 01:16 PM)rprosperi Wrote:  The best solution is to use high quality brands of newly purchased cells

You Nailed It!
I've started doing my research, reading reviews, and now I avoid cheap batteries in anything that I really care about.

[AnnoyedOne]

In my experience not many things come with "cheap" batteries pre-installed. If they come with batteries they're often packaged separately.

Whatever the case it is probably better to use quality named brand ones and ditch the cheapies or keep them for emergency use.

I have a bunch of brand name CR2023's on-hand for a number of things (not just calculators). And AA's. These days shelf-life is long (10+ years) so there's really no reason not to. Buy spares when they're cheap.

A1

[gentzel]

(11-26-2024 01:47 PM)AnnoyedOne Wrote:  In my experience not many things come with "cheap" batteries pre-installed.

Flashlights is a not uncommon example of this. They want batteries in to you can demo them through the blister pack, but they're generally either very cheap alkalines or worse yet "general purpose" batteries.

[RPNerd]

(11-26-2024 01:16 PM)rprosperi Wrote:  Regarding the title of this thread, it is not correct that the 15c CE is overly sensitive to battery quality

That's a fair and valid observation. The original topic title did make it look like I thought the calculator, and not the batteries that ship in it, was garbage. I don't know why I put the blame on the calculator because it isn't at fault.

I have now changed the title.

FWIW, the calculator has been rock solid since I yanked out those noname coin cells and put a pair of GP cells in there instead.

[RPNerd]

(11-26-2024 01:47 PM)AnnoyedOne Wrote:  In my experience not many things come with "cheap" batteries pre-installed.

I see it happening more and more. Put the batteries in the device and you no longer have to manufacture separate packaging to accommodate them. Save a few cents on something that's mass produced and you end up saving quite a bit of money. Similarly, a cheap Chinese battery that performs poorly is going to cost less than a decent branded battery, maybe only a few cents less, but here again, multiply that by the number resold and you start saving considerable amounts of money.

(11-26-2024 01:47 PM)AnnoyedOne Wrote:  If they come with batteries they're often packaged separately.

Either packaged separately or installed but with a plastic insulating sheet with a tab on it that you have to pull for the battery to make contact with the terminals in the device. Either way round, the battery isn't discharging into the device while it's sitting on a shelf in a warehouse. Except when you decide to save another cent or two and don't bother with the insulating tab any more.

(11-26-2024 01:47 PM)AnnoyedOne Wrote:  Whatever the case it is probably better to use quality named brand ones and ditch the cheapies or keep them for emergency use.

You can't even keep the cr*p batteries for emergencies because they tend to have a very poor shelf life. By the time you actually need one it's already going to be dead. Just don't buy them. If you're going to keep spares, make sure it's the good stuff and save yourself a lot of trouble.

(11-26-2024 01:47 PM)AnnoyedOne Wrote:  I have a bunch of brand name CR2023's on-hand for a number of things (not just calculators). And AA's. These days shelf-life is long (10+ years) so there's really no reason not to. Buy spares when they're cheap.

100% agreed.

[AnnoyedOne]

(11-26-2024 05:25 PM)RPNerd Wrote:  You can't even keep the cr*p batteries for emergencies because they tend to have a very poor shelf life. By the time you actually need one it's already going to be dead.

FYI I just changed the 2x cells in my HP-15C CE and HP-12C+. "Pr Error" both times even though I swapped one cell at a time (they're in parallel). The original cells are gone and Energizer ECR2032 (240mAh) ones are ordered.

The stuff in the HP-12C+ has been re-entered (no VoyagerSave functionality--you listening Moravia?) and my HP-15C CE is currently in 16C mode with programs being entered/saved.

All a PITA but do once.

A1

[rprosperi]

(11-26-2024 05:10 PM)RPNerd Wrote:  

(11-26-2024 01:16 PM)rprosperi Wrote:  Regarding the title of this thread, it is not correct that the 15c CE is overly sensitive to battery quality

That's a fair and valid observation. The original topic title did make it look like I thought the calculator, and not the batteries that ship in it, was garbage. I don't know why I put the blame on the calculator because it isn't at fault.

I have now changed the title.

FWIW, the calculator has been rock solid since I yanked out those noname coin cells and put a pair of GP cells in there instead.

Thanks for that, new readers will not be mislead and have to read the full thread to grasp the key points. I usually don't ask folks to rename threads, suspecting most folks are not quite as anal as I am and don't want to be bothered, so I'm glad you did it yourself. Thanks!

[HPing]

I don't think it should ship with any batteries. The retailers can offer batteries that are separately packaged.

I can understand the desire to include batteries in toys to reduce "buyer friction". But these calculators are designed for engineers, so battery installation should be within the scope of "most" buyers.

[mfleming]

Here's something to ponder. The HP15C CE I received months ago worked fine, no key bounce problems at all. Then more recently I began to see certain keys repeating when pressed, often enough that I was going to pull out my cable and update the calculator software.

Remembering this thread, I thought, why not change the batteries? Replaced the 2032's that came with the calculator with some Amazon Basics in their adult-proof packaging. Yep, no more bounce. Puzzling...

~Mark

[Steve Simpkin]

(Yesterday 08:01 PM)mfleming Wrote:  Here's something to ponder. The HP15C CE I received months ago worked fine, no key bounce problems at all. Then more recently I began to see certain keys repeating when pressed, often enough that I was going to pull out my cable and update the calculator software.

Remembering this thread, I thought, why not change the batteries? Replaced the 2032's that came with the calculator with some Amazon Basics in their adult-proof packaging. Yep, no more bounce. Puzzling...

~Mark

Well that is very interesting!