Three significant issues come to mind when I think about batteries. First, they are expensive. Second, they leak. Third, depending on the technology, they can burn down your house. Nasty, right? Therefore, it makes sense to eliminate them altogether. Well, a few weeks ago, I shared a method to power via USB our vintage laptops (here). These cable adapters pull power from a USB adapter and deliver the proper voltage, typically via a barrel plug, replacing the original power adapters. I used such a device by BirdCord happily with the NEC PC-8201A and a power bank. All good.



But what if your device works only with batteries? Indeed, AA or AAA battery-powered vintage pocket computers or programmable calculators often don’t have power adapters. In this case, the main problem with using batteries is the strict discipline one must enforce, at the risk of leaving batteries in their devices and paying the consequences as they leak. We don’t want that to happen ever again!



This is when a battery eliminator gets handy. These devices, invented during the 1920s to replace the batteries used by radios, are straightforward and dumb. Meaning they work very well. In the scenario I described, I can leave the eliminators at rest in my computers as long as needed. I can even forget them, and they will never leak.




Indeed, a battery eliminator is composed of dummy batteries. An adaptor powers one of them to deliver the requested voltage. Depending on the use case, the AA and AAA kits can provide from 3V to 12V. This changes, of course, for other battery types. Regardless, a kit’s other batteries are plain dummies (a simple shorting wire). After testing a few, I prefer kits with a variable power adapter so I can use the same kit with different systems. However, a fixed kit can be cheaper if you want to leave it in place forever – for example, with my PDP Pixel Pals.




The powered dummy should have a flat wire to the adapter so the device’s battery compartment cover can be closed without issues. For example, I used a Lenink Kit with a CASIO FX-890P with two battery covers! It works as a charm.




Simply follow a few basic rules. First, choose the correct voltage. If, like the FX-890P, your device uses four AA batteries, that’s 1.5V x 4 = 6V. Then, pick or set the suitable power adapter. Second, install all the dummies (powered and shorted) in the device. You can position the powered dummy where ever it makes the flat cables’ exit the most convenient. That’s all, folks!



One may notice that through the process, we lose our mobility. True. If mobility is still required – a fair ask with a pocket computer, for example – you can use a USB battery elimination kit. Ah, one last point. Since these batteries are dummies, don’t even try recharging them. And from now on, I can get rid of my AA & AAA batteries to power my pocket computers and programmable calculators.



Last but not least. In 2012, a federal judge ruled in favor of Duracell (that is, Procter & Gamble Co/Gillette) in a class action, considering that the ten years guarantee in storage – the Duralock Power Preserve technology –meant precisely that: a pledge to replace or repair if your battery, in use or storage, leaks within ten years. It is, therefore, not a guarantee that these premium batteries will not leak for a decade. I think it is fair to assume we all knew they could 😊.

Nowadays, I use Panasonic Eneloop Rechargables (or their Ikea equivalents) whenever I can. Touch Wood I haven’t had one leak. The most annoying and expensive Duracell leak destroyed a central heating controller which cost £130 to replace. That happened over the summer when the heating wasn’t needed.
The strange thing is I have picked up 35 year old calculators in which the original Japanese batteries have been fine. In contrast last year I found a ten year old item in which the still sealed included Duracell batteries had literally disintegrated. Some people say that it was the removal of mercury from the batteries which causes this.
I haven’t had much luck with Lithium Ion batteries in power banks etc. I have had about four items in which those batteries have swelled up when the item has been left unused for a few years doing nothing. One swelled up so much it warped the case and broke the display on a Sony MP3 player. How will todays gadgets with built in non replaceable batteries be fairing in 30 years time?
Hi Duncan, Happy Sunday! As always, thank you for sharing your experience here. Yes, I also use the Eneloop batteries with no problem. They still need to be recharged regularly, so it is still a chore for rest-in-place applications. I remember looking for the solar charger in the US many years ago – when they launched the product – and it could be bought only in Japan. I am wondering if it can be found now elsewhere. That being said, maybe you have already watched the experiences of Dave Jones on the leakage topic. If not, here is a link to his videos: https://www.youtube.com/playlist?list=PL24OiKqd2iN9n2Xk_7Y0gN5t44vtBud_C
To your last question, I have the weakness of believing we all know the answer already 🙁
Have a fantastic week ahead!