Connecting a battery directly across the output of a power supply is never a good idea from an engineering viewpoint. Okay, I am a conservative engineer when it comes to circuit design, but it still is not a good idea.
Jim is correct, however he does not stress the point enough, that the power supply MUST be adjusted to the correct float voltage for the battery. First, we are talking about lead-acid batteries (including gel-cells) here. NEVER connect a NiCad or NiMH battery across a power supply. NiCad & NiMH batteries are charged by constant current, NOT constant voltage. Applying a constant voltage across a NiCad or NiMH battery can have catastrophic consequences -- they can (and will) explode if the voltage is too high by even a few tenths of a Volt or so. The proper float voltage for a typical automotive battery is slightly different than that for a marine/deep-cycle battery. A couple of people have asked about damaging the power supply if AC power is lost with the battery still connected. The answer is YES. The regulator circuit used in the Astron linear power supplies (and most other brands as well) will be damaged if power is turned off with a battery connected to the output. Electrically, a battery acts like a capacitor with infinite capacitance. Lee's method of connecting a very large capacitor, such as 1 Farad like he uses, is the best solution to holding the power supply voltage up under peak load conditions. A bleeder resistor across the cap is not a bad idea, either. 73, Ray, K9DUR http://k9dur.info _______________________________________________ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/ Message delivered to arch...@mail-archive.com
