Hi, does anyone know why you should need to disconnect the battery to unplug and change the seat over to a new seat that is the same as the one you are replacing or is it not necessary to do so??

Because the seat has an airbag in it, and stray electrical sparks could cause it to detonated.
You should really disconnect the battery 30 minutes before you start unplugging the seat connections. Hyundai Ioniq 5 Ultimate. The family car.
2009 Rimini Red SE TD4. Gone.
2006 Tonga Green i6 HSE. Gone.
Audi A5 convertible, my daily driver.
1972 Hillman Avenger GT, the project.

I did wonder if that was the case, thanks yes I will have to do that then, better safe than

Having had a seat airbag go off inches from my face while working on a BMW seat, I'd fully recommend disconnecting the wiring. Glad i was at the front of it and not the side at the time. Scared the out of me! 😱 Landrover - turning owners into mechanics since 1948

2014 Orkney grey Freelander SD4 GS.
2004 Zambezi silver Discovery 2 Td5 (Gone)
1963 Surf blue Morris Mini Minor Super de Luxe (my little toy)

Just a thought but there is a thread on here somewhere about a guy who replaced a seat and the car wouldn't start afterwards. Something to do with the seat was from a scrapyard having been in a car in an accident and a sensor was telling the car's computers to shut down. 3 x FL1 2 manual + 1 auto
5 x FL2 4 manual + 1 auto
Now Discovery Sport P250 MHEV SE

Also to make sure it’s right for the model year!

Had to "tell" my 2005 Jag x type that the vehicle had been fitted with a replacement passenger seat occupancy sensor via SDD when I changed the seat.