I have an old tv with an IR remote control. It has become quite bothering for me to change the remote control's batteries every other week. I thought to myself why not connect a Chinese phone battery (which costs not more than 2 bucks) to the remote and I'd only have to recharge the battery probably every other week but that is would be wonderful because I don't have to get out of home to buy a pair of batteries.
I got a phone battery which is 3.7 and my remote control takes two AAA batteries (1.5+1.5=3). I thought why not? that 0.7 volts could not short circuit the remote. As soon as I wired the battery to the remote and I pressed a button, the remote's light turned on and that was its last breath. I put new batteries (AAA ones) in and I couldn't get it work again. I also noticed when I put the AAA batteries back in, the remote's IC was really hot. I can only come to conclusion (my Electronics not being that good since 7th grade) that 0.7 difference in voltage did indeed short circuit the remote.
But I am not going to give up. I have turned up here to find out how I can do this no matter how many remotes or batteries I am going to ruin.
Your help is much appreciated.