Is there a safe or better way of using an AAA battery in place of an AA battery in small electronic devices/ sensors, when in bind like pandemic?

For possible use in small electronic devices without moving parts; remotes (IR, Bluetooth, RF etc) or sensors (temperature/ humidity type sensors) etc.

PS: Not using a motor, so this question title though similar, is not related.

There are plenty of sites/ you tube videos that talk about using an aluminum foil as a connector.

Given how it's a crumpled sheet and not a SOLID type connector, I would think it is subject to weird electrical properties (and hence not recommended), as compared to a SOLID connector.

Only if devices has some kind of "spring loaded" connector which allowed them to use "either" AA or AAA.

:) Wishful

(Although FireStick 4K remote connectors are nice cylinders (spring loaded) & not just thin coiled dpring wires (unless something of that type might help).


Is there a safe, decent, SHAPE/ OBJECT / MATERIAL that can be easily be used in place without the flaws with such hacks with foil?


So, the solution would revolved around:

  • Conductive item (preferably solid) to fill in for the Length & not dodge / wiggle around
  • Non conductive surround/ wrap around stuff to fill in for the Width an prevent dodge / wiggle around

Given the uncertain times ahead of us (this could have impact for 6-12 months on all kinds of supply), I've found both answers useful - and better than Foil ball. Open to more.

PS: We are in an asian city locality surrounded by Hot Zones - even medicine & food are hard to procure. A friends building, one case was detected - police lock down for 2 weeks now.

Is there a safe or better way of using an AAA battery in place of an AA battery in small electronic devices/ sensors, when in bind like pandemic?

Its not the time to be close minded or nit-picky given that both are decent solutions, if one ends up with AAA's at home (due large no of devices) and needs AA in a pinch.

  • One "adapter-kit" is something to keep, get if one is able to, for longer term, a must have that I was unaware of, given that AAA batteries & devices are common & around
    • (kinda like have all kids of screwdriver heads even if you rarely use a certain type),
  • Other - DIY w object or similar from home/ hardware (a bolt in linked SE answer)
    • Would appreciate more such "DIY" ideas with the decent "electrical properties", better than a foil ball.

2 Answers 2

  • It would be somewhat ugly, but I would say tape to bulk the battery up to the correct width, so that the holders / enclosures keep it in place.

  • For the length, I would use a generic 6mm nut

    • Its 5.2mm long which makes up for the length difference in most cases, while having enough width to not move too much, and will make reliable contact with a number of AA holders.
    • I am assuming you would place this on the negative side between the battery and the spring
  • \$\begingroup\$ Like this, as no waiting for the post ie ordered parts and the 6mm nut is inspired... \$\endgroup\$
    – Solar Mike
    May 17, 2020 at 10:57
  • \$\begingroup\$ Nice. Thanks. I am wondering what else could be additional good "in place" - non- conductive width & length space household/ workshop objects \$\endgroup\$
    – Alex S
    May 17, 2020 at 11:05
  • \$\begingroup\$ you want it to make contact, but not be conductive? Then take a pen and cut a 5.1-5.4mm long cylinder and fit however you want it to conduct in that cavity? obviously remove the ink reserve first. this would likely need to go on the positive side so the bump keeps it in position. \$\endgroup\$
    – Reroute
    May 17, 2020 at 11:11
  • \$\begingroup\$ @Alex S; aluminum foil is likely the most widely available and easily adapted material. It would need to be compacted well and used carefully to avoid a loose fragment from ending up in the wrong place. My workshop has a 60 year accumulation of bits and pieces plus a few inherited bits. I could produce something pretty close to a purchased adapter without leaving my house. For something quick and simple, I might be tempted to quickly make up a paper tube and just finish with tape, but the method of this answer would be hard to beat. \$\endgroup\$
    – user80875
    May 17, 2020 at 17:05

Is there a safe, decent, SHAPE/ \$\color{red}{\text{OBJECT}}\$ / MATERIAL that can be easily be used in place without the flaws with such hacks with foil.

Just use a converter like this: -

enter image description here

  • \$\begingroup\$ If I can get one in current lockdown. What are they called anyways? \$\endgroup\$
    – Alex S
    May 17, 2020 at 11:00
  • 1
    \$\begingroup\$ I just did this google search for AAA to AA converter. All the regular low quality sites like ebay, alibooboo, bangbad and amazon seem to sell them \$\endgroup\$
    – Andy aka
    May 17, 2020 at 11:04
  • \$\begingroup\$ And all I got was the Foil hack.. maybe phrased differently \$\endgroup\$
    – Alex S
    May 17, 2020 at 11:06
  • 1
    \$\begingroup\$ Search for "AAA to AA converter" and look for images in results. \$\endgroup\$
    – Andy aka
    May 17, 2020 at 11:07
  • \$\begingroup\$ This isn't a very useful answer, since someone who could buy that could presumably just by the appropriate size battery. If there's utility, it's in the inspiration for what form a DIY solution might take. \$\endgroup\$ May 17, 2020 at 15:11

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