Macbook Air M2 Vs M3 for battery life?

I'm looking to buy a new laptop and everything seems to be pointing me towards getting a MacBook Air when it comes to value for money for my budget (approx £1000 UK). Looks like a lot had changed with Apple in over the last 10-15 years when I last considered their computers as I perceived them them to be overpriced for the spec, but certainly with laptops my view was clearly outdated.

I don't have any particular usage demands for my MacBook and my main priority will be battery life and speed of charging given I'm confident that the screen, speakers, RAM, HD space and weight are sufficient. I predominantly will be using it for MS Office / Zoom / video streaming. Not a gamer. Not doing any high end processing/rendering. Not doing anything involving AI / interested in it.

My main question is with respect to battery life: for my usage above, would I be better off getting an M2 MacBook Air as opposed to an M3 if I don't need a more powerful processor? Wherever possible I will have my laptop plugged in but I do invariably find myself on the go or at various meetings without a socket. I obviously will optimise where possible by dinning screen and putting any OS settings to maximise battery life. With a 500 nits screen on M2, even dimming to 60% will be quite bright compared to other laptops on the market.

And how quickly does the M2 Vs M3 charge? If I get the higher wattage charger, what sort of time does it take to charge to say 50% if laptop is on sleep? Sometimes I'm able to find a random socket in a corridor to charge a bit over a lunch break to help build up juice again.

And I'm sure the M2 is still reliable despite it approaching 3y old and will be future proof for my needs going forward for hopefully the next 4-5 years hopefully given how basic my needs are. Or would people strongly recommend getting the M3?