Dave, A simple switching inverter connected to the solar cells with multiple windings would prevent over charging as the voltage output would be regulated to the voltage of a single cell and the windings providing isolation between cells. This would insure an equal charge to each cell preventing early battery failure. Using FET switches for rectification can boost efficiencies to over 90% even using input voltages as low as 2 Volts D.C.
Art, KC6UQH -----Original Message----- From: amsat-bb-boun...@amsat.org [mailto:amsat-bb-boun...@amsat.org] On Behalf Of Dave Guimont Sent: Saturday, August 13, 2011 6:11 PM To: Phil Karn Cc: amsat-bb@amsat.org Subject: [amsat-bb] Re: ARISSat-1 battery eclipse voltage decreasing > >Disclaimer: what follows is entirely my own personal opinion, not >necessarily that of the ARISSat-1 team or anyone else. I might be >missing information that would affect my analysis. > >Ken's plot is extremely valuable. It strongly suggests battery failure, >not a negative power budget as Tony, AA2TX suggests. Note the sharp and >consistent *increase* in daylight battery voltage that occurred late on >Aug 11, roughly coincident with sharp *decreases* of voltage during >eclipse and reports of computer resets and extended low power operation. >This is inconsistent with a negative orbit-average power budget. If that >were the case, the battery would never reach full charge and the voltage >would never rise so high. Phil, How about you designing circuitry/program to charge "cells" individually rather than the "battery". Or has that been tried?? 73 Dave 73, Dave, WB6LLO dguim...@san.rr.com Disagree: I learn.... Pulling for P3E... _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb __________ Information from ESET NOD32 Antivirus, version of virus signature database 6374 (20110813) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com __________ Information from ESET NOD32 Antivirus, version of virus signature database 6375 (20110813) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
