Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!clyde!uunet!aplcen!uakari.primate.wisc.edu!zaphod.mps.ohio-state.edu!usc!henry.jpl.nasa.gov!elroy.jpl.nasa.gov!gryphon!pnet02!kris From: kris@pnet02.gryphon.com (Kris Means) Newsgroups: sci.electronics Subject: Re: battery chargers Message-ID: <23118@gryphon.COM> Date: 5 Dec 89 16:20:21 GMT Sender: root@gryphon.COM Organization: People-Net [pnet02], Redondo Beach, CA. Lines: 44 In article <28220@amdcad.AMD.COM> phil@diablo.amd.com writes: >I just found a source of 12 V 6 AH sealed no maintenance lead acid >batteries for $10 each. They seem to have a lot of applications (house >burglar alarm, CB radio power, video camera and lights, etc) so I am >looking for some advice on what a charger needs to do. What is an >appropriate fast charge rate? Is it ok to trickle charge them in a >burglar alarm application? What does the discharge curve look like? >How should a fast charger know when to turn off? Do lead acids have >the memory problems of NiCads? Is it ok to leave them flat? What is >the best condition to store them in? The July '86 issue of Radio Electronics magazine ran a construction article for a "Universal Battery Charger" intended for gel-cells. Basically, it uses a LM317 as a constant current source, and when the terminal voltage approaches full charge, it trips an SCR that brings the circuit back as a voltage regulator for a constant voltage trickle, or "float" charge. Klay-Corp in New York makes PC boards for the charger. I changed the layout to use it as a motorcycle battery charger (higher charge rate) and sent the artwork to Klay-Corp, so be sure to specify which version you want. BTW, you can find the complete motorcycle battery charger article in rec.motorcycles. Klay Corporation, Inc. 106 Mark Drive Syracuse, NY 13209-1808 (315) 635-5862 ---------------------------------------------------------------------- Kristopher Means Luck is the residue Van Nuys, California of design. (818) 343-5850 email: sometimes, not always. UUCP: {ames!elroy, }!gryphon!pnet02!kris INET: kris@pnet02.gryphon.com