I think we crossed some wires here. Pun intended. Brook said the fumes ate away the traces and he is right. On a flooded cell batteries such as he describes the fumes are nasty. Its quite normal on a flooded cell to purposely drive them into overcharge. This is known as equalizing. I have to do that on my 2000 Lbs battery from time to time. On Gel Cells that is a very bad process and you don't do it because they will vent. My only wisdom is this. Stay away from hamfest/flea market batteries. They are almost always bad and nothing really revives them. Pay the money and make sure you get a recent build date. Regards Paul. WB8TSL
On Mon, Jul 28, 2014 at 1:44 PM, Alexander Pummer <[email protected]> wrote: > as long as it is not a gals/ceramic seal, there is no way to stop sulfuric > acid to get out from the cell, just imagine the dilatation diffrence > between plastic and metal... > 73 > Alex > > > On 7/28/2014 10:12 AM, Ed Palmer wrote: > >> As I understand it, the only time that any sealed lead acid battery will >> vent is in the case of gross overcharging. The battery is designed so that >> normal charge rates and correct float voltage will result in recombination >> of any hydrogen and oxygen produced. Was there a fault in the charging >> circuit or perhaps, the charging circuit didn't have proper temperature >> compensation of the charge voltage? >> >> Ed >> >> On 7/28/2014 10:56 AM, Brooke Clarke wrote: >> >>> Hi: >>> >>> Using lead acid batteries and a precision frequency standard is not a >>> good thing if they are too close together. >>> >>> A number of decades ago (before the Time Nuts or the internet) I was >>> able to purchase a rack mount Gibbs 5 MHz double oven frequency standard >>> that used a very nice Bliley glass tube crystal because it was not as >>> precise as is was supposed to be. It used GelCell backup batteries that >>> were physically in the same rack chassis as the oven. The fumes from the >>> batteries when charging etched some traces off the PCB inside the oven >>> defeating the temperature control but leaving the oscillator. It took a >>> long time to reverse engineer and repair it. I've added a photo of the >>> cord wood construction of the cylindrical oscillator. The core of the >>> cylinder holds the glass bottle crystal and the glass piston coarse tuning >>> capacitor, surrounded by the first heater, circuitry for the oscillator and >>> dual temperature control circuits on ring shaped boards. These fit inside >>> a cylindrical cavity which is the outer oven. I've added a photo of the >>> inner assembly at: >>> http://prc68.com/I/office_equip.html >>> >>> Have Fun, >>> >>> Brooke Clarke >>> >> >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to https://www.febo.com/cgi-bin/ >> mailman/listinfo/time-nuts >> and follow the instructions there. >> > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/ > mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
