Banner Batteries - topping up

I havewa couple of 110Ah Banner batteries that need topping up. For the life of me I can't get the tops off! Tried all sorts of way to unscew them, but all I am doing is distorting the plastic. Is there a knack to it please?

 

I had similar problems when we got our van 3 years ago. Use a coin of appropriate size (I use a 20p) rather than a screwdriver.
@Terry gave me a tip and that is to use a pair of pliers to grip the coin rather than your fingers.

 

Not stating the obvious but they are not the sealed for life type are they?

 

How do you know it needs topping up if you can't see inside?

 

Transparent sides show the level. Clever these Austrians

 

No they are not - they are supposed to be filled up and there are 6 screw in tops on each to do so. But I can't unscrew them.

 

Graham, thank you so much. Spot on with both tips. A 20p coin plus pliers worked a treat. Thank goodness we had a 20p coin here in Portugal.

 

Glad it worked. Now that you have taken the caps off once you probably won't need the pliers in future - unless you've power-tightened them of course

 

When I top batteries up (and I have encountered your problem) the trick is, whatever your using to unscrew the caps, make sure it's thick enough to fit snuggly in the gap. We've probably all used a flat blade that's too thin and ended up chewing the head up. .. I found a large chunky flat blade that covers the width of the recess did the job for me, it helped that i applied a bit of downward pressure to avoid any slipping, but works well for me.

 

Banner says that you need a flat screwdriver 14mm - 16mm wide. That is a very wide screwdriver. I did not have one in my toolkit and could not find one in shops in Portugal.

 

Banner sell a special tool to remove the caps but its about £20. You can make one yourself quite easily. Go to your local hardware shop and buy a couple of "T" shape cabinet support brackets. The thickness is a perfect fit but they are slightly too wide. A couple of secs with a bench grinder (or couple of mins with a metal file) sorts them out. I found a slightly rusty one lying around my garage. See photo.