I have one of those hand-held mega-candle power rechargeable spotlights. It's getting a little old & the battery is failing. Instead of buying a new battery, can I convert it so that it runs directly off a corded current as opposed to running from the battery?

I've already tried jumping the current directly from the plug-in adapter to the bulb with no results. I get the feeling that there's something different about current running from the adapter to the battery compared to what's running from the battery to the bulb. Can anyone offer some insight?