If you do replace the battery, make sure you keep the old one, they are worth a few bob when sold to scrap metal merchants for the lead content. Theres lots of lead peroxide/sulfate plates in there too which adds to the weight. The H2SO4 electrolyte is heavy as fuck too. Good idea to fill it right up to with water too if its to be sold on, just 'top it up' and make sure its full to the brim with liquid, to make them heavier, as scrap yards go by weight.
Got quite a bit for those in the past. Certainly worth doing assuming the fuel expenditure doesn't cost more to get to the yard. Chances are with
all the romanian trash stealing war memorials etc. and robbing copper cabling from phone exchanges, train line wiring and such you need ID, do here anyhow. If you are going to walk and save gas money to make a higher profit, or get a lift off someone else, then if you got a few bits of copper pipe scrap, brass, aluminium if theres a respectable weight of it then you can make yourself a nice handful of notes. Got 20-25 pounds UK last time for
a single battery plus a few bits of copper pipe and lead scraps from a broken window or two from a derelict building (well really, noone else was going to come for it that owned the building, only people coming for that lead and copper were other people scavenging the place for metal.
So I'd rather me than them. Better the money went in my wallet and gave me some money for a burger or two on the way home, plus a quick trip to the hardware and auto stores for conc. sulfuric and hydrochloric, formic acids, ammonia and diethyl/diisopropyl ether.