Over the years using various torches and batteries I've probably had a combination both of bad batteries and torches over discharging it's battery/batteries before cutting out. Not sure about a bad charger. Mine are labeled as RCR123A if you're going to be pedantic. I just refer to them as CR123A's because they're the same size - same as an AA battery being an AA battery whether it's a rechargeable Ni-MH or an alkaline. I can't remember all these 18650 & 16340 etc numbers they're nonsense.
@tenohfive Haven't you ever had a discharged 18650 or CR123A battery, or any other Li-ion battery for that matter which your charger wouldn't charge? I've had to connect them up to my little solar panel to kick them back into life lots of occasions. They have (or are supposed to have) over-discharge protection as well as overcharge protection. I agree they pack much more punch (higher capacity & voltage) than AA's which is why I use them in my torches I use for bike lights, but in my experience they can also be unreliable and a pain in the arse which is why I've gone off them. I always have take a spare torch along on the bike because 18650 & CR123A's are so unreliable. I've used my Fenix E25 on the bike before which is surprisingly bright for something so small which runs on a couple of AA batteries. Having the option of being able to use ordinary alkalines if you need to is an advantage as well.
I'd avoid torches which use CR123A & 18650 batteries which are even worse they're nothing but a pain in the arse (I use them as bike lights) due to their overcharge protection and if you buy them off eBay they're likely old laptop batteries as well which have been sent to China for disposal and then sold back to us. There's nothing wrong with a small torch with good NiMH batteries in it. The Fenix E25 is a great little torch which runs on 2 x AA's I use it all the time around the home and take it camping.