Wii remote intermittently powering off

wii-remote-powering-off.md

Symptoms

Wii remote will randomly power off when in use.

Cause

This is most often caused by a bad connection between the batteries and the contacts, which is frequently due to corrosion from current or past battery leakage. This is fairly common with standard non-rechargeable alkaline batteries.

Prevention

Use rechargeable batteries, which seem to have little to no leakage.

Troubleshooting

Try each of these steps one at a time, only moving to the next step if the issue isn't resolved:

1. Remove the battery cover and check for leaking batteries. Always dispose leaking batteries and don't reuse them.

2. Check the battery contacts to see if they're corroded due battery leakage (past or present). If this is the case, remove the corrosion with vinegar then clean with 99% isopropyl alcohol.

   ⓘ The chemical that leaks from alkaline batteries is a base, and vinegar contains acetic acid which will dissolve it

   ⚠️ Use only enough vinegar to clean the contacts and don't let it leak inside the device; vinegar contains mostly water which can damage electronics

3. Power the remote on, take the battery cover off and spin the batteries in place. If the remote loses power, it may be a bad connection with one or more of the contacts.

   ⓘ This is the same test you'll use after each of the following steps to check whether the issue persists

   💡 If you're not near a Wii for testing, you can also press the Sync button in the battery compartment (or press the 1 and 2 buttons together) and this will cause the four bottom lights to flash for about 20 seconds while you test for power loss

4. Try replacing the batteries to see if that fixes the issue

5. Immerse the top battery contact in vinegar

   1. Remove the batteries and then remove the top contact by applying pressure to it in the direction of the batteries (e.g. with a small screwdriver)

   2. Immerse the top contact in a small amount of vinegar

   3. Leave the contact in the vinegar only for a short while, until it stops bubbling

      ⓘ Since vinegar is an acid (albeit a weak one), I don't think the contact should be left in the vinegar any longer than necessary

   4. Clean the contact with 99% isopropyl alcohol and optionally put it in the vinegar again (cleaning with 99% isopropyl alcohol afterwards)

   5. Before replacing the top contact, you can also bend it slightly so that both sides apply more pressure on the batteries.

6. Immerse the bottom contacts in vinegar

   1. Disassemble the remote (https://www.ifixit.com/Guide/Nintendo+Wii+Remote+Disassembly+and+Corrosion+Cleaning/141908)

   2. Two of the battery contacts are directly attached to the board. Make sure the battery contact solder joints are intact.

   3. Fill a very small container with vinegar and place the board over the container so only the contacts are immersed in the vinegar

      ⚠️ Make sure the vinegar is only touching the contacts and not the electronics on the board; vinegar contains mostly water which can damage electronics

   4. Leave the contacts in the vinegar only for a short while, until it stops bubbling

      ⓘ Since vinegar is an acid (albeit a weak one), I don't think the contact should be left in the vinegar any longer than necessary

   5. Clean the contacts with 99% isopropyl alcohol and optionally put them in the vinegar again (cleaning with 99% isopropyl alcohol afterwards)

   6. Reassamble

7. Try cleaning the battery contacts with baking soda, which is abrasive. Then clean with 99% isopropyl alcohol.

8. If the connection is still bad, you could try lightly sanding all four battery contacts, then clean with 99% isopropyl alcohol.

   ⚠️ This should only be used as a last resort, as the battery contacts seem to be coated with a corrosion-resistant metal. Sanding them may remove this coating, which won't prevent the contacts from working but may make them more prone to corrosion and possibly even rust. This could also cause the surface of the contact to be uneven, making the connection to the battery even worse.

9. If none of the above worked, hack the lower contacts to put more pressure on the batteries

   1. Disassemble the remote (https://www.ifixit.com/Guide/Nintendo+Wii+Remote+Disassembly+and+Corrosion+Cleaning/141908)

   2. Two of the battery contacts are directly attached to the board. Ignoring the contact with the spring, find the spot where the other contact (the flatter one) goes inside the plastic remote housing. You'll want to fold a small piece of paper in there (I folded it so it was four layers thick) so it goes in between the contact and the plastic, forcing the contact slightly toward the battery for a better connection.

      ⓘ This will only be helpful if the battery isn't touching the contact or is only barely touching it. Making sure the contacts are properly cleaned by following the previous steps will have a much better impact. This could also potentially put undesired pressure on the contact and damage the solder joint, although I don't think this is likely.

   3. Reassemble

10. Finally, you can purchase replacement contacts and replace them, but this will require soldering the new contacts.