2009 Califonia Vintage Electrics problem

A friend of mine has an 09 Cali vintage with about 9k on the clock he has had it about a year the battery was replaced just before he bought it , that battery failed about 8 weeks ago so it was replaced with a yuasa battery now thit battery has failed it was taken back to where he bought it (Halfords) where it was tested and pronounced knackered ,is there any known issues with the Cali vintage wiring system (reg/rec that can be responsible for causing problems.

in the 8 weeks the Yuasa battery was fitted were there any problems like poor starting, dim headlights or suchlike ?,
look at first for a simple reason like loose earth connections,like the one on the rect/reg on the front of the bike next to the horns, that is if the Vintage set up is the same as the Cali EV’s.
I have a friend with a Vintage and he is not what you could call a caring owner as far as day to day maintance goes but his battery is 3+ years old and gives no problems. and I dont recall hearing any bad reports re the Vintage electrics,
I can understand a battery getting run down due to for example a naff rec/reg but to knacker a battery in around 8 weeks is beyond me., I presume the wires going to the battery are all clean and tight.

I would suggest checking if the charging voltage is too high .

Malc

Have had 2 brand new batteries, (one car one bike) go T/U within weeks, both reputable makes. They were exchanged without question and both suppliers reckoned it was nothing unusual.

Yes had that with a Westco Battery from TanyaUK.
They swapped it over the phone no quibbles.

Thanks for the replies lads (sorry I did not get back to you sooner) Halfords replaced the Yuasa battery straight away after testing it they said it was U/S .
I will be having a look at it this weekend to see if there are any issue’s with the earth wires.
Thanks again. Jack