13.5v input for small TV

A friend just bought a small portable TV that has a 13.5 volt input jack on it. He has a power adapter that is the correct physical size of the jack, fits in perfectly, but it's 15 volts. He has a 13.5 volt adapter also, but its plug is wrong, and would require slicing it off and putting a new one on. We were wondering if we could get away with the easy option and just use the 15 volt one? He didn't mention whether anything was AC or DC. He just bought it and wants to power it.

It seems like the most sensible thing to do is to splice the correct plug onto the 13.5V adapter. The 15V adapter may work fine, but I can't advise it with what little information I have. The current requirements of the TV, and the amount of current supplied by each adapter becomes an unavoidable issue at some point.

Most of those adapters have labels on them that will tell you if AC, DC, current and voltage. None of them (that I've noticed) ever mention anything about regulation or filtration. Your TV probably wants DC but look at the specs for the TV to be sure.