Long term battery concern

[Carsen]

We all know that the HP Prime has a rechargeable battery in it and I have a concern about it. When the HP Prime's rechargeable battery dies, how can I replace it with a new one? Can I expect to be able to replace it's rechargeable battery 30 years from now?

My dad currently still uses his HP 15c everyday and is able to get batteries for it. It is turning 31 years old in 2018. Will I be able to do the same with the HP Prime?

If not, then I guess it's fine. After all, I'll have a HP 50g and a HP 48gx to be able to get batteries for. At least, it's more likely that AAA batteries will still be around 30+ years from now.

[webmasterpdx]

31 years from now, you can buy a new calculator :-)

[Carsen]

If I can't use my calculator 31 years from now, then what is the point of collecting them? To me, I need them to function in order for me to want to collect them. Plus if I cannot get my HP Prime to last 31 years, it shows that the quality and design of these new calculators are not meant to last, which if that is the case, I want the older HP calculators back.

[cyrille de brébisson]

Hello,

We did try to use commonly available batteries for the HP Prime, however, it is likely, as you pointed out, that none of these batteries will be available in 30 years and that all the "old" bateries will be long dead...

Unfortunately, the options are rechargeable batteries or alcalines (which most likely will be still here in 30 years).
Alkalines are relatively bulky and result is much large devices, which is one of the 2 reasons why Prime, as a flagship product, moved to that type of batteries. (the other reason is that with the Prime power consumption, alkalines would be short lived and need constant replacement).

Of course, it is always possible to power the calculator using a 3.6V power supply or 5V USB connector.

Cyrille

[matthiaspaul]

(09-07-2017 06:02 AM)cyrille de brébisson Wrote:  We did try to use commonly available batteries for the HP Prime, however, it is likely, as you pointed out, that none of these batteries will be available in 30 years and that all the "old" bateries will be long dead...

Actually, I'm quite sure it will be difficult to get a quality replacement battery in five years already. Newer Samsung phones use a different type of battery, so there is no incentive for battery manufactures to produce new batteries of this type for much longer.

If you try to get a replacement battery for a five year old smartphone, it will be already quite difficult not to get new-old-stock or nonames of questionable quality. New-old-stock, however, will be a waste of money, because lithium-ion-batteries unfortunately deteriorate even if they aren't used at all (not as much as when they are used, but still enough so that they are typically declared dead a few years after manufacturing already). They can only hold a fraction of their nominal capacity any more.

Quote:Unfortunately, the options are rechargeable batteries or alcalines (which most likely will be still here in 30 years).
Alkalines are relatively bulky and result is much large devices, which is one of the 2 reasons why Prime, as a flagship product, moved to that type of batteries. (the other reason is that with the Prime power consumption, alkalines would be short lived and need constant replacement).

There are other options as well, for example, NiMH batteries. Even for low-self-discharge-type NiMHs the available capacities are increasing all the time, so that it has become pure joy to use them in devices such as a HP 200LX, 48GX or 50g now.

While they may still be a limiting factor for power-hungry devices such as the Prime now, think five or ten years into the future. I don't think users would complain about a too short battery life by then any more.

Personally, I even think the Prime is a bit too thin, but perhaps that's because I'm used to AA- and AAA-battery-powered calculators. What I would have preferred (and suggested for a future model variant) is to offer a somewhat thicker replaceable back with integrated battery compartment for 4 or 8 primary or rechargeable batteries in AAA form factor. Either the calculator or the back should include the charging circuitry already - charging should be through the existing USB port (not a separate plug). Technically, that would be trivially easy to do, and if offered for a reasonable price (30 - 50 EUR perhaps), I think, a lot of the "more serious" users (and the collectors - although I'm not sure if there are many Prime collectors), basically all who plan to use the Prime for more than a couple of years only, would buy it as an accessory for the Prime. As, for the reasons given above, there are quite many people who try very hard to stay clear of devices powered by lithium-ion batteries (except for in short-lived devices), there even might be some who would start considering the Prime only after such option exists.

Greetings,

Matthias

[webmasterpdx]

You could make sure you keep the specs for the power requirements, then in 30 years, you can get a tiny regulator and a tiny carbon nano material based supercap battery the size of your fingernail that will fit in the battery compartment....which you'll probably be able to get by then.

[eried]

(09-07-2017 05:23 AM)Carsen Wrote:  If I can't use my calculator 31 years from now, then what is the point of collecting them? To me, I need them to function in order for me to want to collect them. Plus if I cannot get my HP Prime to last 31 years, it shows that the quality and design of these new calculators are not meant to last, which if that is the case, I want the older HP calculators back.

You can create an adapter for newer types of batteries available in 30 years
https://www.thingiverse.com/thing:237922

[Tim Wessman]

Well, we did pick an incredibly popular device that is still being sold new in some places of the world and modeled our battery to be the same size and electrical configuration. You can still find 3rd party batteries quite cheaply from a huge range of retailers...

Kind of the best we could do. AAA batteries just wouldn't cut it for many reasons and most people do not plan on keeping and using the device 30 years from now...

[Carsen]

Thanks all for the good ideas. Eried, that video was fantastic!!!

Overall, I think I'll just enjoy the HP Prime now and "cross that bridge when I get there". Especially when I have potentially more technology and resources to fix a potentially dead rechargeable battery with no replacement on the market. Or maybe I'll become disinterested in the calculator. After all, the RPN is rather lacking. The only thing I really love about it is that TOUCHSCREEN.