The information presented on this web page is copyrighted by the original author / provider (i.e. APC, Falcon Electric, the ARRL (QST)). Other information is copyright by repeater‑builder.com (the author's copyright, if any, supercedes it).

This page contains articles related to alternative and backup power systems, such as Uninterruptable Power Supplies (UPSes), Battery Backups (BB), Photo-Voltaic (PV), and other sources of energy besides the regular commercial (mains) power.

Repeater-Builder welcomes artlces about implementation and modification of such systems.

UPS-related Information:

	UPS Technologies   An explanation of the major UPS technologies, common power problems, and information about choosing the right unit to solve them. Summarized from information on the web.
	Testing the switching time of UPS units   By Robert W. Meister WA1MIK Some units switch from mains power to the inverter faster than others. The author ran some tests and captured some waveforms from a couple of common UPS models.
	Modifying an APC SU1000 for extended run-time   By Robert W. Meister WA1MIK The run-time of a UPS is directly related to the battery capacity. It's relatively easy to install larger batteries in a lot of the different APC units (a SU1000 model is shown). This article shows you how to do it.
	One manufacturer's explanation of various standby and UPS power systems   Off-site link to their article.
	The SBS & UPS tutorial   from Falcon Electric Great explanation of the various technologies. 242kB PDF file.
	On-Line UPS Block Diagram   from Liebert's GXT2 On-line UPS Owner's Manual Probably typical of the true on-line units. 206kB PDF file.
	APC Corp Application Note #12, The APC Computer Interface Port   140 KB PDF "This application note provides technical information regarding APC UPS computer interface ports. This information is for customers attempting to use the port for unsupported purposes." Note that this is for the units that have a female DB-9 connector on the back. With the information from this applications note you can interface digital inputs on your repeater controller and detect the presence of AC power, etc.

Alternative-Power-related Information:

	Solar Power for Your Ham Station   A reprint of an article from QST April 1996. 186kB PDF file.
	Storage Battery Maintenance and Principles   A reprint of an article published by the Department of the Interior, Bureau of Reclamation, December 1997. 1.2MB PDF file.
	Practical Battery Back-Up for Amateur Radio Stations - Part 1   from QST March 1990, by George Thurston W4MLE (SK)   1.16 MB PDF Despite it being over 20 years old this three-part article is well worth reading for the background info and overall theory.
	Practical Battery Back-Up for Amateur Radio Stations - Part 2   from QST April 1990. 1.5 MB PDF file.
	Practical Battery Back-Up for Amateur Radio Stations - Part 3   from QST May 1990. 1.0 MB PDF file.
	Practical Battery Back-Up for Amateur Radio Stations - all three parts as a single file   from QST for March, April and May 1990. 3.7 MB PDF file.
	Sealed Lead Acid Battery Charger   by Luke Enriquez VK3EM.
	An Automatic Sealed-Lead-Acid Battery Charger   By Bob Lewis AA4PB from QST for May 2001   136 KB PDF This is a clever little charger that not only charges your batteries, but can keep them on trickle charge safely.
	The Micro M+ Charge Controller   By Mike Bryce WB8VGE   289 KB PDF This unit is an excellent small (4 Amps max) solar panel charge controller for charging gel cells or just about any lead acid battery. It has a standby current of under 1 mA.
	The 12 v pup   By Yaniko Palis VE2NYP from QST for June 1970   385 KB PDF
	Reader comments about batteries   Compiled by Mike Morris WA6ILQ Discussions on various battery technologies and war stories.