Battery warranties

[markweatherill]

Over the last couple of days, my car has started showing signs that the battery is giving up. Just slower churning when I start it and a low battery voltage. This is since the weather turned a little colder which might just be coincidence.
It was bought from Halfords a year or so ago and came with a three year guarantee, which I still have the receipt for
Does anyone have experience of claiming for a failing battery under these guarantees?

 

[markweatherill]

I discovered the battery '+' terminal was covered in that corrosion fluff. I cleaned it off and WD40'd it and it's all OK again. I'll give it a proper clean up to make sure.
I did read somewhere you can put a copper penny near the terminal and it will 'soak up' the corrosion, saving the terminal. So I'll try that.
Thankfully no need yet to test the 'guarantee'.

 

[markweatherill]

Whenever I disconnect the battery I get GF to put the last one back on. I really don't like the little 'crkk' noise it sometimes makes...
I once jump started my car using the jump leads the wrong way round on the other car. That was a big spark.
Apart from that I follow the rule of take the negative lead off first and put it back on last, which is sensible 'just in case'.