Grease for battery connections?

FxFocus

Finding my (electric) wheels
Aug 5, 2020
6
2
My bike (Carrera Subway E) got it's first soaking today and upon removing the battery when I got home I found water had collected in the area around the terminals attached to the bike. I remembered reading something about greasing the terminals to prevent corrosion but I'm unsure what type of grease to use. Googling resulted in conflicting advice, much of which I found ambiguous.
Would some kind soul please put me out of my misery and just tell me exactly what I need to buy for this purpose.
Thanks in advance :)
 

Edward Elizabeth

Pedelecer
Aug 10, 2020
136
191
Buckinghamshire
Personally, I wouldn't use anything as you don't want grease getting inside the terminal recesses on the battery where they will attract dirt, grunge up, and start to form an intermittent connection.

I keep my terminals clean, and every time I clean the bike I give them a spray of ACF50 to stop corrosion forming.
 
  • Like
Reactions: FxFocus

Andy-Mat

Esteemed Pedelecer
Oct 26, 2018
2,214
562
78
My bike (Carrera Subway E) got it's first soaking today and upon removing the battery when I got home I found water had collected in the area around the terminals attached to the bike. I remembered reading something about greasing the terminals to prevent corrosion but I'm unsure what type of grease to use. Googling resulted in conflicting advice, much of which I found ambiguous.
Would some kind soul please put me out of my misery and just tell me exactly what I need to buy for this purpose.
Thanks in advance :)
Myself, I would be more concerned with how the water got there in the first place.....
At Halfords you can buy grease for lead acid battery terminals, which may help, I used to use Vaseline or white lithium grease , it certainly did no harm on LA, but probably there is something better around today for Li-ion, or guessing only, they do not need greasing possibly...!
I will wait and see what others post as I am also interested!
Andy
 

Edward Elizabeth

Pedelecer
Aug 10, 2020
136
191
Buckinghamshire
The issue is that standard battery terminal or dielectric grease is for static terminals. Our bikes have terminals that move every time we detach or refit them, and that provides a mechanical means by which the grease can work it's way inside the terminal recesses on the battery. On a static, permanent connection that isn't a consideration.
 

Woosh

Trade Member
May 19, 2012
20,383
16,880
Southend on Sea
wooshbikes.co.uk
unless the contacts are gold plated and the connection box airtight sealed, they need a minimum amount of grease to keep dirt, water and oxygen away from the metal surfaces. The latter can corrode the metal.
Dirt can also decrease the conductivity across the contacts and cause sparks when you ride over a bump - which is not good for your controller.
Any grease will do but you should prefer a neutral pH grease.
 
  • Agree
Reactions: Wisper Bikes

FxFocus

Finding my (electric) wheels
Aug 5, 2020
6
2
Myself, I would be more concerned with how the water got there in the first place.....
My battery fits on the down tube and the connection is at the bottom contained in a sort of cup with no drain holes. Water running down the outside of the battery is getting in and collecting in the bottom of the cup.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,917
8,533
61
West Sx RH
Vaseline is readily available, good for your hands as well.
 
  • Like
Reactions: Swizz

Wisper Bikes

Trade Member
Apr 11, 2007
6,283
2,252
69
Sevenoaks Kent
Whatever you use, only use a tiny, tiny amount. Filling up an area with grease can cause huge problems, occasionally we see bikes sent back to us that "don't work". Often on these bikes we open the controller or look at the battery connections and find copious quantities of gunk, which 99% of the time is the cause of the problem. It's amazing that we also find that no one knows how it got there!!! :rolleyes:

All the best, David
 
Last edited:

Woosh

Trade Member
May 19, 2012
20,383
16,880
Southend on Sea
wooshbikes.co.uk
if you choose to grease, do so sparingly. You need enough grease to fill in the micro valleys on the surface of the metal. No more.
If you put a large wodge of grease, when you close the battery, the grease will be pushed into between the contacts which is counter productive.

Grease helps with delaying formation of oxide film:

 

FxFocus

Finding my (electric) wheels
Aug 5, 2020
6
2
Many thanks for replies...

I never intentionally ride in the rain but English weather being what it is my bike is sure to get wet occasionally. When this happens I'm thinking the best course of action will be to dry the area around the contacts with a rag and then use a hair dryer to completely dry the contacts before spraying with ACF50.

Not sure if the hair dryer is necessary if the ACF50 also removes any wetness?

It seems a light smearing of grease will do the job but which grease specifically?

Just had an afterthought... would directing warm air over wet contacts be counter productive?
 

Woosh

Trade Member
May 19, 2012
20,383
16,880
Southend on Sea
wooshbikes.co.uk
The hair dryer itself is not an important factor.
you need an electrolyte between two pieces of metals to cause formation of an oxide film. To have an electrolyte, you need two things: water + a salt of some sort. It does not have to be sea salt, as long as it has some H+ or OH- in it to conduct some electricity.
Rain water may have carbonic acid but it's dirt really a problem.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,917
8,533
61
West Sx RH
A fine smear of Vaseline is all that is needed on metal.
I use Vaseline on the metal work in my beehives to help protect the metal surfaces, I sterilise using Ethonic acid 80% to kill any viruses and spores present (sans bees)at the end of season (when cleaning ready for the new season in spring). The Vaseline film stops the acid from attacking the metal work.
 
  • Like
Reactions: Bobajob