Best not to do.Ventillate with known positive airchange if you do.Be SURE not to abuse-charge.You probably won't die. Probably. > > It will be fine... natural ventilation is fine just don't seal it in a > > box... > > Steve > Got it. Thanks! For some flavours of 'it'. Fine / won't explode (probably). Fine / wont hurt the carpet/drapes/fish ... probably. Fine / Won't give you cancer 40 years from now from breathing the xxx probably ... You will probably not notice not getting away with having charged a SEALED lead acid battery indoors. Probably. Maybe not today. Or within a montyh. Or a year. Or a lifetime. Or ever. If Murphy decides to have fun you may never notice the effect even if it is notceable, or at least, may not twig the correlation A house/hostel / office IS a box - how are you not going to put it in a box= ? The Nth Am cruising club whatever official US wide power boat peoples say ALWAYS ventillate. As you'd expect. We don't know and you may not know what inside means, how long, if it will "gas", ... . You MAY get some Hydrogen release. Probably no effect. Worst case somebody dies. Unlikely. You may get mild H2SO4 fumes release. Probably worst case is that brittle spot on the carpet by the wall over there and I wonder why. Worst worst worst case is probably cancer ior whatever 10 20 30 40 years on - and that's luck of the statistical draw along with all the other stuff. Long ago (40 years?) I charged a 12V light truck battery in my bedroom, with the door closed, while I slept. It gased. Badly. Uphill both ways feet box ice ... . It took many days to get over the throat agony, weeks to get over the sore throat. Cancer? Not yet. A far as I know :-). ____ Best not to do. Ventillate with known positive airchange if you do. Be SURE not to abuse-charge. You probably won't die. Probably. Russell --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .