Cranking voltage

I have one of those battery monitor devices that i used on my old car. I decided to put it on my 8 month old vRS. It regularly reports “!low cranking voltage”. I saw it drop to around 9v. Should it not drop below 9.6v?

The car starts fine. No short journeys and it tests ok on my Topdon battery tester and has good voltage. Seems a bit odd? Unlikely a battery can be faulty after 8 months and 20k miles?

Edited 6 January, 20251 yr by Micky 32