[rab] Yes, though I cannot give you brand(s) or model number(s). It does however involve having two (usually small plug pack) power supplies (unless the 'receiver' has one built in) - one for the receiver - that's the one which connects to the landline - and one for the 'phone handset, which is simply a battery charger. I've just had a look at mine, an el-cheapo Panasonic unit, but it does not have the facility though I'm sure that one of my previous units (Uniden?) did, even though I didn't use it.
[rab] I've got a BT Quartet system which I bought about 4 years ago [though mine is only the 'duet' version because I didn't see the need to buy 3 handsets]. The base station with aerial plugs into phone point and power socket down here in my kitchen/officy place and the portable handset sits on its own charger which is plugged in upstairs in one of the bedrooms. The phone itself often gets lost in one of the bedrooms but appears to keep its charge for days without sitting it back on its power plinth. Very handy - it's even effective from my friend's house which is a few doors down the road.
[Chalky] It's more of a 'monet' that I'm after: base station + 1 handset + charger separate from the base station (as the base station has to sit in a place where I don't want to put the phone to charge).