Since I bought my P38 it's been a bit lazy turning over, never starts on the first go but always kicks in on the second attempt. I've been advised I should try changing the battery, so I want to go for the biggest one I can get (both in AH and CCA). However, all the big reasonably priced batteries seem to have their terminals the other way round to mine (positive is on the left on mine).

So... I can either fork out what seems to be about double the money for the same spec battery with terminals where I want them, or make up some new cables and re-route them so I can fit something like this: https://www.ebay.co.uk/itm/1x-Exide-Premium-100Ah-900CCA-12v-Type-017-Car-Battery-4-Year-Warranty-EA1000/191792348430?epid=0&hash=item2ca7b6fd0e:g:8BgAAOSwqrtWp18g

Anyone done the new battery cable / re-routing before or is it more trouble than it's worth?

If the battery is the problem, then the best battery to fit is the MF31-1000, from here:

https://www.batterymegastore.co.uk/hankook-mf31-1000.html

No need to change any battery cables. It is basically the defacto P38 battery.

Brilliant, thanks, I've ordered one of those :)

If it’s a bit lazy, it could be the starter rather than the battery, have you tested your old battery