Logitech MX620 - 10 months and batteries still limping along

[#1]

I've been really impressed with the battery life from the Logitech MX620 mouse.
The MX620 I use at work had its batteries changed in March 2012 and in October I got the SetPoint notification that the battery level was low (5 or 10% can't remember) and in December it told me to replace them. But in spite of SetPoint giving up on estimating the level now, and the red battery critical LED being illuminated it soldiers on.
I've previously used rechargeable mice (with proprietary batteries or NiMh AA with built in charging capability in the mouse) and they seemed to be forever plugged in to recharge the batteries (some models lasted a week at best, others maybe a month) so the Logitech came as a surprise.

[#2]

My MX 1000 laser mouse was great at first. Now, it only lasts a couple of days before I have to put it on the charger. Even then I have to fiddle it about to get it to start charging at all. I thought some time ago that this mouse was on it's way out, so bought another Logitech; the MX Air. I hated it's scroll and ended up going back to my knackered mouse! I've long bought Logitech and lately I'm finding their quality has lapsed. I also recently bought another webcam - a HD one. The picture was diabolical, worse than my older model, so I sent it back.
On a positive note: my Logitech cordless Rumble pad is still going strong some 6-8 years down the line.
As for SetPoint. I'd bin it. It became serious bloat-ware years ago.

[#3]

My wired mouse still doesn't need any batteries.