I have an 110amp battery, in the caravan and that is kept in the drive 
maintained on 'shore power'. The built in power unit, (normally) keeps 
the battery charged and I give it a very occasional boost with a 
'proper charger' -except....

The RCD tripped some time ago and a TV antenna booster was left on + 
the green 'voltage OK' LED between them on flattened the battery.

Once I had sussed out the RCD, I expected the battery voltage to 
quickly come back up to a full charge on the power unit, but it didn't. 
The battery has round posts and the quick connect clamps [1] have never 
been a particularly good fit on them. A bit of oxidation on the clamps 
and lead posts had prevented the battery charging up.

I have just spotted the reason why those quick connect clamps have 
never fitted very tightly. Around each tapered lead terminal post is a 
plastic coloured ring - red for positive, black for negative. Great 
idea, they avoid your connecting up the wrong way and destroying 
something expensive and vital. Except the reason the clamps never 
fitted too well was these plastic rings. The clamps were never able to 
go down the taper far enough to clamp on properly, spaced off by the 
thickness of the rings.

[1] These are the clamps to connect the power cables, with a coloured 
plastic hood which lifts to disconnect, press down and it tightens onto 
the post.

-- 
Regards,
        Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

Harry Bloomfield wrote:

> I have an 110amp battery, in the caravan and that is kept in the
> drive maintained on 'shore power'. The built in power unit,
> (normally) keeps the battery charged and I give it a very occasional
> boost with a 'proper charger' -except....
> 
> The RCD tripped some time ago and a TV antenna booster was left on +
> the green 'voltage OK' LED between them on flattened the battery.
> 
> Once I had sussed out the RCD, I expected the battery voltage to
> quickly come back up to a full charge on the power unit, but it
> didn't. The battery has round posts and the quick connect clamps [1]
> have never been a particularly good fit on them. A bit of oxidation
> on the clamps and lead posts had prevented the battery charging up.
> 
> I have just spotted the reason why those quick connect clamps have
> never fitted very tightly. Around each tapered lead terminal post is
> a plastic coloured ring - red for positive, black for negative. Great
> idea, they avoid your connecting up the wrong way and destroying
> something expensive and vital. Except the reason the clamps never
> fitted too well was these plastic rings. The clamps were never able
> to go down the taper far enough to clamp on properly, spaced off by
> the thickness of the rings.
> 
> [1] These are the clamps to connect the power cables, with a coloured
> plastic hood which lifts to disconnect, press down and it tightens
> onto the post.

We spotted this a while ago, and swapped to 'proper' clamp on posts on
all our 'vans since.  The time taken to ondo the clamp pales into
insignificance when you realise that, in our case anyway, you only take
the battery out once a year.

It's also worth bearing in mind, if anyone else wants to do this, that
it's worth getting a matching pair of posts, one post is slightly
smaller diameter/taper than the other, so it's not worth trying, say,
two positive terminals ... ;)

-- 
Paul - xxx

'96/'97 Landrover Discovery 300 Tdi 'Big and Butch'
Dyna Tech Cro-Mo comp "When I feel fit enough'

Harry Bloomfield said the following on 15/07/2008 22:40:
> 
> 
> I have just spotted the reason why those quick connect clamps have never 
> fitted very tightly. Around each tapered lead terminal post is a plastic 
> coloured ring - red for positive, black for negative. Great idea, they 
> avoid your connecting up the wrong way and destroying something 
> expensive and vital. Except the reason the clamps never fitted too well 
> was these plastic rings. The clamps were never able to go down the taper 
> far enough to clamp on properly, spaced off by the thickness of the rings.
> 
> 
Even batteries have to be 'politically correct' these days!
I can see little point in having quick release clamps, when in the majority 
of cases the battery is seldom if ever removed. When I used to rely solely 
on battery power, I had a separate battery enclosed in a plastic carry case 
with a 12N connector for connection, so removal for charging was simple.

Roy