Indie put a new battery in the car when I bought it 3 weeks ago as the old one was flat (been sitting on the forecourt for a few weeks)

He put in a cheepy by the looks of things. Only 800 CCA and when I put the meter on it the reading was 11.8 volts.

When starting from cold I turn the key and all the lights come on, does it's system check and then I crank it. The first few attempts it refuses to turn at all. If I'm insistent and try another 4 or 5 times it turns. When it does turn it turns well, like there was nothing wrong with battery charge at all and sparks straight up.

I am guessing that the low voltage on the battery it triggering something in it's world of electronics that says "voltage too low, don't bother trying". If I'm insistent it eventually gives it a go and finds it's fine.

Is my guess right? Will getting a decent quality 950 CCA battery like this

https://www.tayna.co.uk/019-Enduroline-Car...-8385.html

solve my problem? I know that at some point in the not too distant future I'm going to get stuck!

I would be checking for a current drain and the alternator output first I think, but this is the recommended battery should you need one (for pre-facelifts): https://www.tayna.co.uk/EA1000-Exide-Premi...P7488.html  Visiting from DISCO3.CO.UK
2006 Discovery 3 TDV6 Auto HSE Zambezi Silver