In a message dated 11/12/04 23:24:04 GMT Standard Time, [EMAIL PROTECTED] writes:
According to the PowerSonic instruction sheet, after "bulk" charging (< 1.6 Amps for my 8 Amp Hr SLA), you are supposed to switch to about 14.2 volts for "absorption" charging. Once the current gets down to 80 ma, you can switch to a 13.8 volt "float" charge indefinitely if you wish. Since you are drawing 80 ma at just 13.8 volts, my guess is the battery is still charging. It should slowly drop to quite a bit less than that, maybe 30 ma or less when totally charged. The "absorption" charging or otherwise called "equalise charge" after the main charging cycle is complete is to equalise the voltages across the individual cells and get the maximum possible energy into the battery. With solar power systems we found that this period was better restricted to about 15 minutes when done daily to save overheating of the battery and consequently loosing electrolyte. Extended overcharging with SLA's greatly reduces their service life. When the battery is on "float" which for a small 12V SLA is commonly done at 13.8V, the current will come out at usually 25 to 50mA depending on the battery. This can be left on indefinitely as is common with fire alarm panel use, though will eventually reduce the capacity of the battery by a degree. Bob, G3VVT _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
