The sealed lead acids are pretty cheap. Try Maplins, or your local non-franchised "big" electronics shop (Taits, in Glasgow, for me). Where are you? Gordon.

If they haven't been treated well, IE charged by a cheap, non-smart charger or allowed to sit uncharged for long periods or othewise abused, or if they're just plain worn out, there's really no hope for them. Sorry. Stories abound about using capacitor banks discharged through them to rejuvinate them, but that's all pretty much folklore with relatively little basis in fact, except for an extremely limited range of circumstances. ***Dispose of them properly*** they contain lead, a toxic metal. In the US, drag them over to Batteries Plus and just drop them off, free of charge, no questions asked, and they will be recycled properly. In the UK...??? There's a variety of sources, but the best deal so far is a corporate account at Batteries plus. I pay a few bucks more for some types, much less for more popular 12v UPS batteries, and save overall. That's my .015 euro. de N9QQB

http://www.homepower.com/files/desulfator.pdf Above shows battery revitaliser cct. Elektor had a more complex cct. in the September 2001 issue. Don't know how successful it would be with sealed gel batteries. CPC / Farnell have similar prices to ARD with CPC offering free carriage with orders over ?30 (ex. vat ) I think Farnell have free carriage over ?10. Again no connection with either company, just use them a lot. Geoff. which case