Getting smart key not found on my 2011 Vogue.

Happens 70% of the time I get in the car. Allied to this its range when locking/unlocking varies wildly from fine at 25 yards, to being having to be next to the car and repeatedly.

What's the general consensus on this? Both the car battery and fob battery have been replaced v recently.

Any assistance to a fix on this would be v much appreciated.

I had to put a Duracell in, didn’t like a brand new Varta in the fob. 2010 Supercharged

The quality of button batteries can be a bit variable.
I'd suggest not buying online - not even from Amazon.
I've had experience similar to yours...

Best bet I think is to buy from one of the Big Four supermarkets.
But even then, visually inspect before dropping them into your trolley as I've had to return a pack having apparent condensation inside the plastic package.

Hope this helps.

Warwick 2011 L322 TDV8 A/b Orkney Grey
2008 Defender 90 XS TDCi Java Black
2002 L322 TD6 Vogue Zambezi Silver (gone but not forgotten)
And one or two bikes - Ok, maybe more than one or two....