Hi

My (Exide Excel) battery has lasted less than 3 years.

When I replaced my battery last week I noticed that there was water on top of the battery, which surprised me, as rainwater should run along the tray beneath the windscreen and down to the side of the car.

I discovered that a lot of the rainwater drips through the hole in the tray (circular press clip / stud ) and straight onto the battery. The battery has a (two-piece) plastic cover over it, but water drips through the gap between the two halves (or through the rectangular hole in the forward section) and onto the battery itself, leading to water languishing on the flat top of the battery, and possibly providing a partial short between the terminals???? It can't help, can it.

So I have sealed the hole around the plastic stud with bathroom sealant so that water no longer drips onto the battery.  I now hope that my brand new battery will last for more than 3 years - more like the 6-8 years that all my previous batteries have lasted.  For a 10 minute job, it might be worth doing.....

 

Don't be afraid to post a photo... Welcome to the forum.

The Exide Excel is a lower end battery.  Only has a 3 year warranty I believe?  You do (generally) get what you pay for with car batteries.

Water on the battery won't hurt it unless it's huge amounts.  My MK2 didn't even have a battery cover (lost presumably), mud, water and salt used to splash over it regularly but it was still going strong at 8 years old.

how strange is that.  last week i also found water on top of battery in same place. how it got there i dont know.  its a mk3

5 hours ago, michaelburrows said:

how strange is that.  last week i also found water on top of battery in same place. how it got there i dont know.  its a mk3

... You do now 😉

Photo attached.

Battery bone dry today.  I accept that the issue might not affect battery longevity, but for a ten minute fix, it's made me a little happier - it just feels 'right' that a battery should be kept dry rather than being positioned under a drainhole. After all, why is that two-part plastic cover there?

Another minor plus is that the steel holding down strap won't go so rusty, which it was beginning to do. 

A long time later, I asked myself the same question and came to the conclusion that it was a design error, of which there are many with this car.

Like you, I told myself that everything was fine, that the battery was dry, etc. etc.

Except that yesterday, I told myself that I had to solve this gear shifting problem, so I had to remove the air box and the battery tray.

And the bad surprise... a completely rusty screw in a little stagnant water even though the weather is super hot!

So I decided to close this hole by glueing a piece of thermoplastic.

For the battery problem, it comes from the following implementation problem : the ground cable which goes from the battery to the chassis is fixed at a point which is painted.

You must therefore remove the bolt, remove the paint, reattach the cable, degrease and apply a coat of anti-rust paint.

It's the same for the cable which connects the alternator to the chassis : it's exactly the same error.

To correct it, you must remove the air box and do the same thing as for the ground cable.