396 xt
It shouldnt hurt anything as long as you didnt charge the alkalines too long, they probly just got a little warm, the worst thing that could have happened is if you left them in there too long then they probly would have blown up inside the battery comparment then you would have ran into some problems, i usually dont ever charge any batteries in my 396 xt, i always keep the switch on the alkaline setting and then i use the energizer 15 min charger to charge 3 at a time, and i have 3 sets of rechargeables so when one set goes dead i just use the other set, the reason i keep the setting on alkaline is that once in a while i will plug the scanner into my cars cigarette plug so i can save on using the battery use so much in case i wanna walk around with it so it dont go dead, and you can also change the internal charge time on the scanner itself if you ever wanna charge the batteries inside the scanner.