Around that would be good, not below 12.5 V. The trouble is though, if they bang them on a charger, even for just a bit of time, then immediately bring them out for you to test, the Voltage they show won’t be the real resting Voltage, it will still be higher than normal due to only just coming off the charger. Really you want to see what the voltage drops to overnight, after its been taken off charge.
Wonder if they’ll try and resell Andy’s! (They said it would go for recycling, but you can take that two ways.)
I’ll let Andy tell you how they messed him round from pillar to post, at two different Halfords branches.
Shame is, I bought one from Halfords last year and it was fine, a good price too, but they appear to be down to the door stops and paper weights now, with these things.