dielectric grease

[MSeries]

It's insulative (insulating) it's it ? So why is it good for electrical contacts ? To prevent arcing ? So once contact it made is the grease scraped off ?

Tyring to make some improvements to prevent my GPS switching off an bumpy roads

[Adrian]

I use a folded piece of paper to hold the batteries in tighter.

[MSeries]

I use a folded piece of paper to hold the batteries in tighter.

where ?

I'd still like to know about the grease though

[Adrian]

Either or both of underneath the batteries and between them and the cover. Just enough to deny the batteries any room to move.

[Biggsy]

Dielectric grease is used for corrosion prevention.  I think it should be applied over the top of stuff rather than between connectors.

You could look for slightly larger batteries.  Not all batteries of supposedly the same size are exactly the same.

The paper trick has helped for me as well in lights.

[Kim]

High-capacity NiMHs that are slightly physically larger than an AA ought to be work fine for me.  I've never had my eTrex randomly switch off with 7dayshop's 2700 and 2800mAh cells.

[border-rider]

It's insulative (insulating) it's it ?

yes, but so is most grease. The thing that makes this different is that it doesn't absorb water and emulsify, so it stays insulating.

So once contact it made is the grease scraped off ?

Yes.

The contact has to be made with the grease physically pushed aside to allow metal-metal contact

Tyring to make some improvements to prevent my GPS switching off an bumpy roads

What the others said - either different sized batteries - the ones I use are a tight fit and I don't have this issue - or some packing material.

edit: cross post with Kim.  i use the batteries as she suggests and I've never had a problem.

[Sergeant Pluck]

As above, certain batteries avoid the problem: Ansmann rechargeables for instance, or lithium cells (re the latter, I assume because they are lighter). Playing with the vibration absorbency of the mount helps - avoid too bouncy a mount, firm but not totally rigid works best.

[MattH]

The vibration of the mount made the big difference for me.
Putting more rubber packing between the mount and the bars made a big difference. I only had a problem with the old etrex legend when it went onto my tri-bars, which vibrate much more than the handlebars, then I put an oversize mount on the bars from the MTB with plenty of thickness of rubber and it was fine.

[Aidan]

The vibration of the mount made the big difference for me.
Putting more rubber packing between the mount and the bars made a big difference. I only had a problem with the old etrex legend when it went onto my tri-bars, which vibrate much more than the handlebars, then I put an oversize mount on the bars from the MTB with plenty of thickness of rubber and it was fine.

Same here. ONly ever had a problem when the Etrex was mounted on tribars. On the handlebars with a good layer of rubber does the trick fine