Woodstock Battery Holder

[teenix]

I was looking for a Woodstock battery holder replacement. I thought I had an original one, but it seems to have vanished.

Looking at Shapeways, you can order the bottom of one for the measly sum of $3114 delivered, unless I am not seeing the obvious.

cheers

Tony

[tangdfx]

Hello，Tony

This could be 3D printed.

I have a lot of them.

if you want I can send you the stl file.

[rprosperi]

I'm happy to send you an original Woodstock battery pack for shipping if original is preferred; of course, probably 2 weeks+ to get there... Let me know.

[teenix]

(10-20-2023 05:12 AM)tangdfx Wrote:  Hello，Tony

This could be 3D printed.

I have a lot of them.

if you want I can send you the stl file.

If you can email it to me, that would be great. My son has a 3D printer, maybe it is good enough to create one.

Thanks.

[teenix]

Hi Bob,

Many thanks again. I finally got around to removing the crusty old batteries and cleaning up the battery holder. Looks pretty good.

Now to have some fun with it and see what I can come up with.

cheers

Tony

[Peter Klein]

For anyone else interested in a Woodstock battery holder...

There's this: https://www.shapeways.com/product/6NQAST...ery-holder
It has a realistic price. I just ordered one, it should arrive around New Year's Day.

Also, if you go to The Auction Site and search for "HP-25 battery," you will find someone who sells 3D printed battery holders for about $20.

--Peter

[ThomasF]

(12-19-2023 07:15 AM)Peter Klein Wrote:  For anyone else interested in a Woodstock battery holder...

... there is also this one:
https://www.thecalculatorstore.com/epage...oodstock3D

They also works fine with normal AA alkaline batteries.

Cheers,
Thomas

[rprosperi]

Although the original Woodstock holder and these 3D replacement holders will work with normal AA cells, the extra length of the button top will make the holder MUCH harder to remove from the machine; many people even think they are stuck and damage the case try to remove it.

It's much better to use flat-top cells, which allow the holder to be more easily removed to extract the cells when they need charging.

And it bears repeating: NEVER CHARGE YOUR WOODSTOCK BATTERIES IN THE DEVICE, always remove them to charge externally. An HP Woodstock battery pack charging cradle is convenient and easier to use, but modern cells charged with a modern smart charger will ultimately last far longer, even if less handy to use.

Here are some of the flat-top AA cells of the type I'm suggesting, though I prefer a better manufacturer such as Tenergy:

https://www.amazon.com/Kastar-Replacemen...7CKFP?th=1

[ThomasF]

(12-19-2023 01:22 PM)rprosperi Wrote:  Although the original Woodstock holder and these 3D replacement holders will work with normal AA cells, the extra length of the button top will make the holder MUCH harder to remove from the machine; many people even think they are stuck and damage the case try to remove it.

Hi Bob!

I have not tried other ones, but I dare you to try the ones from Calculator Store!
They are made with a material that is much thinner in the end (but still strong enough), and I think they are MUCH easier to remove than the original HP pack (at least the ones I got), and that is with normal AA cells!
I also use normal rechargeable AA batteries that I charge outside the calculator.

I have replaced all mine and will not go back - my only wish was another color, but I can live with that

Cheers,
Thomas

[rprosperi]

(12-19-2023 05:10 PM)ThomasF Wrote:  Hi Bob!

I have not tried other ones, but I dare you to try the ones from Calculator Store!
They are made with a material that is much thinner in the end (but still strong enough), and I think they are MUCH easier to remove than the original HP pack (at least the ones I got), and that is with normal AA cells!
I also use normal rechargeable AA batteries that I charge outside the calculator.

I have replaced all mine and will not go back - my only wish was another color, but I can live with that

Cheers,
Thomas

Hi Thomas,

In fact I have not tried the bat holder from TCS, it sounds like the thinner material compensates enough to use button cells w/o trouble; I had not imagined that, but if so, well done Jose (!) for yet another clever solution for ages old problems for these old machines.

Still, I have the same objection to these 3D pacs, the totally wrong colors just scream "I'm a modern fake" from across the room; for reasons I can't explain, it just matters to me enough that I don't use them. But I've been lucky, I found a listing on eBay some years ago that included more than 10 Woodstock battery packs. After removing the old cells and cleaning, they're ready for new cells, but the old-style "thick" walls don't work well with button-top cells.

A Woodstock was my initial HP love; though a lowly HP-21, it opened my eyes to RPN, but I suppose it could also be considered my gateway drug...

Happy Holidays!

[Sanjeev Visvanatha]

(12-19-2023 09:44 AM)ThomasF Wrote:  

(12-19-2023 07:15 AM)Peter Klein Wrote:  For anyone else interested in a Woodstock battery holder...

... there is also this one:
https://www.thecalculatorstore.com/epage...oodstock3D

They also works fine with normal AA alkaline batteries.

Cheers,
Thomas

For a similar design, thingiverse has this one:

https://www.thingiverse.com/thing:1276886/files

I sent that to my local public library, and it was about $2.50 CAD and was ready the next day. Works well with the AA springs I bought on TAS.

[Divasson]

Hi,

The thingiverse STL is not the same drawing as The Calculator Store’s : we drew it ourselves from scratch in Autocad Fusion. For one thing, ours has sides that contain the batteries.

As we have not printed thingiverse’s, I can’t say whether there are significant differences or not - just wanted to say that it is NOT the same drawing.

We use our hp41 spring which fits perfectly too.

[vaklaff]

(12-20-2023 02:12 AM)rprosperi Wrote:  In fact I have not tried the bat holder from TCS, it sounds like the thinner material compensates enough to use button cells w/o trouble; I had not imagined that, but if so, well done Jose (!) for yet another clever solution for ages old problems for these old machines.

I have and use it as well, the thin wall and the different spring work great with full-length AAs, definitely no problem with opening.

(12-20-2023 02:12 AM)rprosperi Wrote:  Still, I have the same objection to these 3D pacs, the totally wrong colors just scream "I'm a modern fake" from across the room; for reasons I can't explain, it just matters to me enough that I don't use them.

First time I hear about this advanced art of calculating with the calculator upside down. Hmm... Deep concentration. Pressing the buttons from behind, just from memory. The results, glowing in red, dancing in front of one's inner sight. No need to check the display. Mystique. Contemplation. Yes, yes, I can see now how a wrong color on the calculator's back can break all the magic! Just kidding :-)

The holder I received from TCS is snowy white and it arrived with an apology and promise that a brown one (or black?, I don't recall) will be sent once they have that material again. I admit the calculator looked a bit strange at first but then I turned it the right side up and just wrote back there's no need to send anything.

I'm glad I myself don't need perfection and at the same time I'm glad there are people who seek it and make effort to restore beautiful things to their original beauty. Cheers!
V.

[Sanjeev Visvanatha]

(12-20-2023 06:17 AM)Divasson Wrote:  Hi,

The thingiverse STL is not the same drawing as The Calculator Store’s : we drew it ourselves from scratch in Autocad Fusion. For one thing, ours has sides that contain the batteries.

As we have not printed thingiverse’s, I can’t say whether there are significant differences or not - just wanted to say that it is NOT the same drawing.

We use our hp41 spring which fits perfectly too.

My apologies, I thought they were based on the same design. I will edit my incorrect post.

[John Garza (3665)]

(12-19-2023 01:22 PM)rprosperi Wrote:  Although the original Woodstock holder and these 3D replacement holders will work with normal AA cells, the extra length of the button top will make the holder MUCH harder to remove from the machine; many people even think they are stuck and damage the case try to remove it.

It's much better to use flat-top cells, which allow the holder to be more easily removed to extract the cells when they need charging.

Also...

Ensure the diameter of the cells are slim enough to slide easily in the pack. They must move freely to compress the battery springs to allow you to remove the pack easily.

And of course, the unrefurbished unit you buy could have swelled and corroded batteries. This will also make removal of the pack difficult.



-J

[teenix]

I didn't know these came apart. Just a bit of old glue holds them together. Might be useful for someone wanting to install modern batteries without cutting into it.

It's interesting that they have battery markings on the inside, probably for someone to install the batteries during manufacture.

cheers

Tony

[Peter Klein]

(12-19-2023 01:22 PM)rprosperi Wrote:  Although the original Woodstock holder and these 3D replacement holders will work with normal AA cells, the extra length of the button top will make the holder MUCH harder to remove from the machine; many people even think they are stuck and damage the case try to remove it.

It's much better to use flat-top cells, which allow the holder to be more easily removed to extract the cells when they need charging.

And it bears repeating: NEVER CHARGE YOUR WOODSTOCK BATTERIES IN THE DEVICE, always remove them to charge externally. An HP Woodstock battery pack charging cradle is convenient and easier to use, but modern cells charged with a modern smart charger will ultimately last far longer, even if less handy to use.

Here are some of the flat-top AA cells of the type I'm suggesting, though I prefer a better manufacturer such as Tenergy:

https://www.amazon.com/Kastar-Replacemen...7CKFP?th=1

Bob Prosperi: Are these are the Tenergy batteries you recommend? They are half the price of the Kastar clones direct from the manufacturer. The Kastars claim 200 mah more capacity, and have slightly larger diameter contacts, but I suspect the former is marketing and the Tenergy contacts are large enough.

https://power.tenergy.com/tenergy-aa-200...e-battery/

-Peter

[rprosperi]

(01-06-2024 12:34 AM)Peter Klein Wrote:  Bob Prosperi: Are these are the Tenergy batteries you recommend? They are half the price of the Kastar clones direct from the manufacturer. The Kastars claim 200 mah more capacity, and have slightly larger diameter contacts, but I suspect the former is marketing and the Tenergy contacts are large enough.

https://power.tenergy.com/tenergy-aa-200...e-battery/

-Peter

Yes, as long as you will be charging them externally in a smart charger (designed for NiMH cells) these cells will probably last several times longer (of actual use) than the originals. Note that NiMH cells do self-discharge at a higher rate than NiCD, so these are not best for long shelf-life (or sitting in a machine not in use), but will provide about the best runtime you can get for a Woodstock or Spice. I agree with your assessment, Tenergy are one of the best brands available.

[Dave1947]

I just finished making a new battery pack for my HP-21. I started with the file downloaded from Thingiverse, printed it but found it was too flexible and was very difficult to insert or remove batteries from the holder. I edited the 3D model to add side and bottom stiffeners, a short strengthening stiffener to the center tab on the terminal end, a groove through the center hump on the bottom for the spring, and most importantly, reduced the length of the battery overhangs on the terminal end to make battery cell insertion and removal from the holder much easier. Links to some photos of the end product.

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[Dreato]

@Dave1947

Would you consider sharing your STL file?

Regards,
Dave (1952)