Older car lead acid batteries give off oxygen and hydrogen and this is why these types of batteries should never be charged in a closed environment. Modern car batteries are usually sealed for life, however, they can still vent gas if over charged or mistreated. I've seen pictures of explosions that happen when car batteries were left on charge over night and the bloke walked in and removed the crocodile clips from the charger and it caused a spark. This normal venting of gas during charging is why we used to have to top-up these batteries from time to time with distilled water - ah.. the good old days. No chemicals were harmed or destroyed in the writing of this Email as the by-product of burning hydrogen in oxygen is only heat and water. -----Original Message----- From: Jake Anderson [mailto:grooveee@OPTUSHOME.COM.AU]=20 Sent: 27 July 2003 11:10 To: PICLIST@MITVMA.MIT.EDU Subject: Re: [OT] Recharging battery emissions Lead acid batteries are basically pretty safe (well unless you drop one on your foot or something) when charged they give off hydrogen gas which is explosive with air in a range of something like 2-90% or something. it would also be possible for them to give off some form of sulphur I spose but it would be a fairly small amount I would imagine. Lithium-ion batteries can create lithium metal if overcharged (or under charged?) which will explode on contact with air. Ni-Mh batteries are pretty environmentally friendly in most respects, NiCad's have cadmium in them which is pretty toxic but in all of those cases they are pretty safe unless you do something wrong to the battery. ----- Original Message ----- From: "Tim ODriscoll" To: Sent: Sunday, July 27, 2003 7:58 PM Subject: [OT] Recharging battery emissions > Hi Everyone, > > The thread a few weeks ago about lead poisoning got me thinking about > other hazards in electronics.. Specifically that of recharging lead-acid > batteries and other rechargeables. > > I know that recharging car batteries gives off some kind of explosive gas > because it was one of the first things my mig-welding mentor warned me > about unplugging the charger before repairing the car, but I've not found > anything by Googling to elaborate on it. > > So would the same warnings hold for other batteries containing lead? I ask > because I've got some 'Sealed Lead Acid' batteries that state they are not > to be charged in a sealed enclosure (which is a bit more oxymoronic than I > like on my safety lables). > > And while I'm on it, how about the other more common types, NiCd and NiMH? > Are they all silently producing dubious gasses? Google only seems to want > to tell me about regulations in constructing the actual battery :/ > > Cheers, > > Tim > > -- > http://www.piclist.com hint: The list server can filter out subtopics > (like ads or off topics) for you. See http://www.piclist.com/#topics -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics