3D Printed Sting 10 / 19C Battery Tray

[aj04062]

Has anyone created the 3D CAD file for this battery shell?

If not, I'll have to model it!

Thanks!
Adam

[Harald]

(01-26-2022 12:03 AM)aj04062 Wrote:  Has anyone created the 3D CAD file for this battery shell?

If not, I'll have to model it!

Thanks!
Adam

A Spice battery holder for 2 AAA cells is available from "TheCalculatorStore". I am not aware of any Sting (10 / 19C) battery holders.

[aj04062]

My error.

STING battery holder

[dmh]

I'm looking for a cost effective option for this too once you find/design something.

I've found a 3D printed one with rechargeable batteries on eBay but it's around $120 AU including shipping to Australia.

Please keep us updated - thanks :-)

(01-26-2022 12:03 AM)aj04062 Wrote:  Has anyone created the 3D CAD file for this battery shell?

If not, I'll have to model it!

Thanks!
Adam

[Jonas Sandstedt]

Hello,

I use the solution described (by me) at

https://www.hpmuseum.org/forum/thread-17716.html

and it works nicely.
Here the battery pack can be easily removed and safely charged outside the calculator, for example by an USB NiMH charger.

I have used a similar solution for an HP-97 with four sub-C celles instead, and it also works very well.

best regards
Jonas

[dmh]

Thanks. I'm not sure I want to modify the calculator as it's in excellent and (appears) original condition.

Is there a removable contact connector that would work? I use alligator clips for testing but not suitable for long term use.

(01-27-2022 08:05 AM)Jonas Sandstedt Wrote:  Hello,

I use the solution described (by me) at

https://www.hpmuseum.org/forum/thread-17716.html

and it works nicely.
Here the battery pack can be easily removed and safely charged outside the calculator, for example by an USB NiMH charger.

I have used a similar solution for an HP-97 with four sub-C celles instead, and it also works very well.

best regards
Jonas

[Jonas Sandstedt]

Hello,

I do not know to what extent you want your calculator to be in original condition, but the solution I propose only involve soldering two small wires to the battery contact tabs which already are covered with (old) solder. This provides a much more reliable electrical connection than the original contact solution between battery poles and the battery contact tabs, and if the wires are de-soldered and superfluous tin is removed, the calculator is brought back to original condition except that the old tin at the battery contact tabs has been replaced with some new tin.

The advantages involve a better electrical contact that reduces the risk of damage to the calculator during charging and the possibility to easily remove the batteries and charge them separately outside the calculators. This totally eliminates the risk of damage to the calculator during charging and a modern NiMH charger can be used (if NiMH cells are used). As shown in the photos, I use a USB charger that can be connected to a USB power source.

Furthermore, modern AA cells are slightly larger than the older ones, and therefore I think it is difficult to fit them properly in the original battery holders that can’t be re-assembled properly, and the battery cover is therefore sometimes hard to close. Dispensing with the need for a battery holder makes this handling easier as well.

Of course, it must be said all types of handling such as soldering and de-soldering involves a risk of damage, but for me it has worked well. Whatever you choose I hope it works well since the HP-19C is a really nice calculator.

Best regards
Jonas

[rprosperi]

(02-01-2022 08:56 AM)Jonas Sandstedt Wrote:  Furthermore, modern AA cells are slightly larger than the older ones, and therefore I think it is difficult to fit them properly in the original battery holders that can’t be re-assembled properly, and the battery cover is therefore sometimes hard to close. Dispensing with the need for a battery holder makes this handling easier as well.

If you will use AA cells, you should only use flat-top cells, not the normal grocery-store AA type with button tops. The original cases, and the intended spring/contact solution was designed for, and only operates properly with the flat-top types; as Jonas alludes to here, the common variety are too tall, don't fit the cases, and can cause removal problems and even damage. Include "flat-top" when you search for cells, they are easy to find online.