Recommended battery pack for HP-19C?

[Joe Horn]

A tedious Google search revealed that 4-AA NiCad battery packs for the Sting Series calculators (HP-10 and HP-19C) are available online from multiple sources, but they all seem to be $50 or more, which seems excessive, and I don't know which sources are reliable. Yes, I know that I can rebuild the ones that I already have, but I'd like to also buy some more as spares.

If you have purchased a Sting battery pack online, please share your impressions of it, and your source, and the price you paid. Thanks in advance!

[Dave Frederickson]

I've replaced all my Classic battery packs with AAA adapters from Mark Hoskins <waterhosko@aol.com>. I can now use AAA alkalines or Eneloops and I'll never need to rebuild a Classic battery pack again.
I'd ask Mark if he can make a 4-cell version for the Sting series, or make one yourself from a plastic 4-cell AAA battery holder.

Dave

[Joe Horn]

(09-22-2017 01:30 AM)Dave Frederickson Wrote:  I've replaced all my Classic battery packs with AAA adapters from Mark Hoskins <waterhosko@aol.com>. I can now use AAA alkalines or Eneloops and I'll never need to rebuild a Classic battery pack again.
I'd ask Mark if he can make a 4-cell version for the Sting series, or make one yourself from a plastic 4-cell AAA battery holder.

Thanks, Dave. I did write to Mark, and he replied promptly that he does not have any Sting Series battery packs, but graciously offered to rebuild any which are sent to him. So I'm hunting for either new ones or a 4-AA holder that can be converted into a Sting Series pack.

Meanwhile, I stopped at Batteries Plus today and bought 4 NiCad AA flat-end cells, 1100 mAH for only $1.29 each. Sweet.

[Massimo Gnerucci]

(09-22-2017 12:31 AM)Joe Horn Wrote:  A tedious Google search revealed that 4-AA NiCad battery packs for the Sting Series calculators (HP-10 and HP-19C) are available online from multiple sources, but they all seem to be $50 or more, which seems excessive, and I don't know which sources are reliable. Yes, I know that I can rebuild the ones that I already have, but I'd like to also buy some more as spares.

If you have purchased a Sting battery pack online, please share your impressions of it, and your source, and the price you paid. Thanks in advance!

Stumbled on this a few days ago...

[jjohnson873]

Joe...I was looking for the same thing, an HP-19c battery pack. I decided to bite the bullet and purchase the eBay pack at vintagecalculatorsinc for $49. It's a very high quality, 3D printed case with 4 Tenergy 1000mAH NiCd batteries. The pack fit perfectly in a recently acquired HP-19c. I have access to a 3D printer, so I may be looking for the SLA files and print the battery case myself. But then I'll need to find a source for the springs. ~ Jim~

[Sadsilence]

When original battery case is still around you can easily open it and insert following cells

http://www.ebay.de/itm/Akku-Pack-im-Poly...Swn-tZEihc

with a little bit DIY work. Higher capacity, LSD feature and still can be charged with geniue wallplug charger.

Sorry, I do not know a source on other side of atlantic ocean.

Nevertheless mentioned professional seller can be highly recommended, too.

[badaze]

(09-22-2017 10:40 AM)jjohnson873 Wrote:  Joe...I was looking for the same thing, an HP-19c battery pack. I decided to bite the bullet and purchase the eBay pack at vintagecalculatorsinc for $49. It's a very high quality, 3D printed case with 4 Tenergy 1000mAH NiCd batteries. The pack fit perfectly in a recently acquired HP-19c. I have access to a 3D printer, so I may be looking for the SLA files and print the battery case myself. But then I'll need to find a source for the springs. ~ Jim~

I bought the same battery pack to the same seller.
Dud you try to charge the battery pack inside the calc with the HP 19C charger ?

[badaze]

I tried to make my own battery pack using standard batteries (not rechargeable).

The voltage is 5.5 V is it enough ? Is it too much ?
Are the batteries well positioned ?



Thank you in advance.

[Maximilian Hohmann]

Hello!

The polarity looks OK to me. The voltage is a little bit on the high side at 5,5V - with the original NC cells for which the calculator is built it would be 4,8V. I have never powered an HP-10 or 19 with disposable batteries so I can't be sure, but the normal Woodstocks do not get damaged by the extra voltage.

Regards
Max

[Dieter]

(10-16-2018 07:18 PM)badaze Wrote:  I tried to make my own battery pack using standard batteries (not rechargeable).

The voltage is 5.5 V is it enough ? Is it too much ?

5,5 V means 1,375 V per cell which is quite exactly the average voltage of a well-charged NiCd, i.e. that's what the original NiCd-pack should have delivered.

But you say these are single use batteries, maybe Alkalines. Here a fresh cell usually exceeds 1,5 V. On the other hand 1,37 V per cell means that the batteries are not fresh or haven been used for quite some time. You may want to measure the voltage with a significant load applied. Here Alkalines are much less suitable than NiCds or NiMHs. At least while the printer is operating the voltage of these partially depleted batteries may drop so low that the printer may not work correctly.

Dieter

[badaze]

Thank you guys !

Anyway I must be cursed because since I put back the rechargeable battery pack I removed to test its voltage the printer works continuously when I switch the calculator on. No display.
I’m so sad.

[Sadsilence]

(10-17-2018 09:35 PM)badaze Wrote:  Thank you guys !

Anyway I must be cursed because since I put back the rechargeable battery pack I removed to test its voltage the printer works continuously when I switch the calculator on. No display.
I’m so sad.

Had one HP-19C with similar problem. In my case I used an external power supply with 5V and 1A current limit and got same result as you and power unit switched to current limiting mode. When removing current limit or using a refurbished battery pack instead calculator worked flawlessy! Obviously HP-19C has such a high inrush current when switched on, that you need a high quality battery pack and minimal contact resistance between components. Try to clean and/or resolder contacts.

[badaze]

Thank you !