HP-80 Battery


I recently purchased an HP80 with no battery - it does have the charger. I don't have the calculator yet, but the battery compartment looks to be very clean. I will either make a battery per the directions given by Doug Jones or buy the Panasonic HHR-P505 battery. Using the Panasonic battery Doug Jones references seems to be the quick route, but is it the best route? Does anyone have hands-on experience with either method? I'm very excited about getting this calculator and I want to be sure to handle the battery issue properly.



sorry for jumping in. But you asked the same thing I ask me since 1/2 year. Have a 19C with clean battery bay; same for a 41CV. But no battery packs.

That means to build some similar case from scratch! Are there any ideas for the 80, 19C and 41C?


Michael and Valentino --

I've bought one of these new fabricated battery packs from this US eBay seller, who repeatedly offers these items. Just search US eBay under "Calculators" for 35, 45,55, 65, 67, 80, etc...

Battery packs for Classics

-- KS



Yes Mark's Hoskins batteries do work flawlessly in the Classics !

To complement Karl's answer, the 19C is not a classic :

It uses a 4xAA battery pack.

The best thing is to use ready-made welded 4xAA or refer to this specific excellent article from Katie Wasserman :


I differ from Katie in the fact that I prefer not to assemble the pack from scratch but use a 4xAA ready welded pack.

Please note that the rightmost & leftmost elements of the pack must be able to move freely to allow proper positioning in the calc.

Now for the connection to the calc. This connection must be absolutely reliable especially if you intend to charge the battery in the Hp-19C.

So :

- either you go for soldering clips to the pack and then "clip" them to the calculator contacts

- OR you go my way which means soldering the battery contacts to the calculator contacts.

BEWARE : Use a temperature controlled iron AND turn off the iron before soldering to avoid current leaks to the calculator.

The Hp-19C is very fragile and I fail to understand why Hp chose to save a few cents on power regulation & limitation when they designed the Woodstock series.

Oh I forgot : my advice is to avoid NiMH packs for the Hp-19C as I wouldn't rely on the Woodstock charger to charge this type of batteries in the calc.

Best regards from a french Clyde.



I have used NiMH batteries in all my Woodstocks including the 19C. They work great and charge just fine... actually they charge better than the NiCads since they are not at the high end of their suggested continuous charge current like the NiCads would be.


Hi again,

ok, more competent advice than mine on NiMh ;-)

I gladly withdraw my last sentence and move to NiMh shortly (I'll try first on my 29C...).

Thanks David !



I have a HP35, I went to the local Battery Plus store and they custom built a pack for me using NiMH cells (better for the environment, but they let you pick whatever cells you want). They also took care of soldering in the V shape contact plates for me, so it was a turnkey solution.

You will find spaces around the pack when you insert it in the HP Classic, and I solved that with thin strips of neoprene with a sticky back to them. When there is no play, you have a lot less problem with the contacts.

The charger seems to work fine with the new cells, and one full charge can last me a whole day.

Hope this helps.

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