Earthing a 12v socket

[SMOKEU]

Do I have to earth a socket on an unpainted metal part of the bike, or can I do it on a painted surface?

[neels]

It will work better on an unpainted bit, or if you want to use an existing screw/bolt then stick a star washer under the terminal to bite through the paint to the metal underneath.

[imdying]

Do I have to earth a socket on an unpainted metal part of the bike, or can I do it on a painted surface?Definitely something bright and shiny, you don't want increased resistance and all the drama that comes with it!

[kewwig]

Do I have to earth a socket on an unpainted metal part of the bike, or can I do it on a painted surface?

The more metal under the connector, the better. Avoid earthing to an aluminium frame - better to run a negative lead as corrosion can occur

[SMOKEU]

The more metal under the connector, the better. Avoid earthing to an aluminium frame - better to run a negative lead as corrosion can occur

I ended up earthing it to the frame, aluminum shouldn't rust anyway.

[imdying]

It can oxidise, it's not magic.

[Daffyd]

I would suggest applying a little silicone gease to the connection to keep the air out.

[Max Preload]

It can oxidise, it's not magic.What's the bet he used a stainless fastener just to make it that extra bit worse... :facepalm:

[slofox]

I ended up earthing it to the frame, aluminum shouldn't rust anyway.

If you have used any other metal than aluminium in your connection, you will get a reaction between the two metals with resulting corrosion. That's how you make batteries - two dissimilar metals in a solution...

[Juzz976]

Wire back to Battery dude, its gonna draw SFA and its not very far to go.

You don't know all the possible return paths for the current, the corrosion may take place somewhere that will compromise the integrity of your frame/mounts. You may not even see where its happening untill it has done permanent damage.

[SMOKEU]

If you have used any other metal than aluminium in your connection, you will get a reaction between the two metals with resulting corrosion. That's how you make batteries - two dissimilar metals in a solution...

I never knew that.


Wire back to Battery dude, its gonna draw SFA and its not very far to go.

You don't know all the possible return paths for the current, the corrosion may take place somewhere that will compromise the integrity of your frame/mounts. You may not even see where its happening untill it has done permanent damage.

Should I earth it to the negative terminal on the battery?

[slofox]

I never knew that.



Should I earth it to the negative terminal on the battery?

Whichever terminal is earthed - connect it to that. Usually the negative.

[SMOKEU]

Whichever terminal is earthed - connect it to that. Usually the negative.

I'll get onto that soon.

[Max Preload]

I never knew that.Look up 'galvanic corrosion'. It's the reason you should avoid using stainless fasteners on aluminium boats unless they're electrically isolated.

[Jantar]

I ended up earthing it to the frame, aluminum shouldn't rust anyway.
You can earth it to the aluminium frame, but make sure that you use a conductive/anti corrosive paste between the connection and the frame, and also use an aluminium alloy bolt and nut. Otherwise you can expect to develp an impossible to find electrical fault shortly before your frame breaks at that point.

Alternatively, find a shiny steel surface to earth it to, or run an eath wire to a known neutral point on your bike.

[SMOKEU]

Thanks for the advice guys.

[notme]

Don't panic too much about the stainless to aluminum thing, getting a good clean earth is the important point here. If it's convenient, run a wire to the battery then you have the best of both worlds, but if it's not then bolt to whereveris convenient and safe, using some grease on the threads.