Battery or not?

Hi All, new to this forum. (Although I suspect I'll become more of a leach as time goes by, whilst I desperately try to keep my old friend on the road.)
Drove 350 miles home from work the other day. Lights on, wipers on (UK dweller), radio on, heater on (refer to wiper comment). Parked up, then 5 min later decided to move the car. Nothing. Dash lights on, nothing, not a sound. Left it an hour, started on the key. Went out, couple of stops, last stop, nothing again, and no luck with attempted jump lead start. 30 minutes later, fine.
Plugged the battery into a charger, comes up as a full battery.
Is the battery duff, or should I look at anything else before buying one?
On another note, how much should I look to pay for a new clutch..... Think that little gem is next on the list... Foot through the floor now to get into first.... 145,000 miles under her belt.
Thanks and I'll be back for more! She's starting to age........
S

What model of Freelander is it?

There have been a few very similar posts started like this of late, eg

https://www.landyzone.co.uk/land-rover/problem-starting.294049/
https://www.landyzone.co.uk/land-rover/fuel-pomp-power-failure.279569/

As that first link says, there's others as well - you might find something in them.

It may be the battery - but it is also likely not - so worth investigating before splashing out on a new one.

Thanks GG.
I did have a quick scan through the forums, although I'm using my phone so it's not as convenient as tablet or desk top.
She's a TD4 02.
I'll check the three possibilities given in your first link. I think the other refers to the previous diesel power house.
Cheers
S

put a volt meter on the battery read it then start up and read it again non running is 12v and running is 14 ish

mine had similar problems showed up on two expensive testers as good battery (one was a snap on ) ,couple off days later smoke pouring out of battery . new battery fitted no more problems .
Trev