Disk Drive (9114) battery pac: Refresh, replace or retire?


Hi all,

when trying to reactivate a 9114 disk drive by loading the accu pack, the latter seems to be exhausted.
The drive only shows a flashing "low bat" sign, the "test" light shines continuously, while the "disk active" light remains off.
Two days of loading didn't change a thing. I tried two packs, one only some years old (approx. '99).

So far the facts. The questions:
1. Do lead-acid packs age over time?
2. Can they be reactivated by several charge/ discharge cycles (if so, how to discharge, when the device doesn't work)?
3. If reactivation doesn't help: How can the charger be connected directly to the drive's contacts (instead of the accu pack's drawer)?
4. If the aboce doesn't help: (esp. German) Readers, do know a source in the vicinity?

One could muse lots about whether devices decades old are worth reactivating, but it makes me merry watching a small machine like the 41 controlling a bunch of others, feeding output, sending control signals, getting input.

Gruß aus Deutschland,


Hi Klaus,

There are at least two good possibilities:

1) Read this posting by Dale Richmond: http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv009.cgi?read=23806

Thanks to Dale, I have a Radio Shack AC/DC adapter, part number 273-1695, which supplies 6.5 DC volts, and successfully drives a 9114B disc drive. Make sure that the polarity is correct in making the connection: the lower slot within the disc drive is positive (+). The HP charger that comes with the disc drive supplies AC, and the wrong voltage, so do not try to use it for a direct connection that by-passes the battery.

2) A new 6V lead acid battery can be obtained from InterstateBatteries.com -- part number SLA0902. Alain on this forum kindly told me about this. It is not much of a job to replace the original battery, though I found on my unit that I had to lengthen the connecting wire within the battery pack just a bit.

Success in getting it fixed! I agree that it is too nice a set-up to let it be retired.

Cheers, Tom


Tom, thank you very much.

I guess, I'll check out German shop chain "Conrad Elektronik" first before getting e-gadgets over the Big Pond. Thus, other "ole'lectronic" enthusiasts over here might like the information, too.



Hallo Klaus,

es gibt hier in Deutschland einen Laden der den benötigten Akku führt, aber ich weiß nicht mehr welcher; Sch...
Aber die Adresse ist hier in einem früheren posting genannt worden(ca. 1/2 bis 1 Jahr her). Ansonsten kannst Du auch 3St. Cyclon Rundzellen von Hawker nehmen (2V/2.5A). Das klappt hervorragend, ist aber etwas mehr Aufwand.

PS: Prüfe mal den Typ 491250-13 bei Conrad


Hallo Klaus,
bei "http://www.akku-shop-ladewig.de/" gibt es den passenden Akku: Panasonic 6V/2.4Ah; LxBxH:66x33x98; 520gr.;
Preis: EUR 14.20


Wow, gut gegraben - ich war nicht so erfolgreich. Vielen Dank. So wird das Porto nicht so hoch...

English tongues, Andreas came up with a source for the 9114 accu pack in Germany.


To answer your questions :

(1) Yes, lead acid packs do 'go off' with time, whether used or not. I doubt that any of the original 9114 batteries are still any good.

(2) Not really. You need to replace the battery.

(3) You can't connect the HP charger directly to the drive, but you can connect a 6V _DC_ power supply to the 2-pin mini-jones plug in the battery compartment. If you open up either the battery pack or the drive, the polarity is obvious (black -ve as usual), but if you're not sure I'll check the schematics.

(4) Take apart the battery pack (2 Torx screws on top, and clips round the edges of the cover). You'll see the block battery and the charger PCB. I am told you can still get suitable replacement batteries. However, 3 off 2.5Ah Cyclon cells (2V Lead Acid cylinderical cells) fit perfectly (they're available from RS components, and elesewhere). Wire them in series, fit them into the pack (terminals away from the charger PCB) and connect them to the wires that went to the original battery. All (3) my 9114s have Cyclon cells in them, and I've never had any problems.

As to whether it's worth doing, I _love_ the 9114, and regard it as the only worthwhile storage for the 41, 71 and 75 machines. Since I use those a lot (yes, they're old, but they're beautiful), I use my 9114 a lot too.

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