Using a typical DC power supply (such as the Astron RS-35M) to power your
Orion plus a backup battery can be more complicated than it appears.
When "floating" a battery continuously, you need to make sure the float
voltage is very close to what the battery manufacturer specifies. Different
battery chemistries require slightly different float voltages. By very
close, I mean within a tenth of a volt. This would mean you may need a
charger with adjustable output voltage (such as the Astron VS-35M) and an
accurate digital voltmeter. Too high a charge will boil the electrolyte
(drying out the battery) and too low a charge will result in a partially
charged battery. Neither condition will help you when you need the backup.
Another issue with using DC power supplies as battery chargers is they may
not be isolated from the load (battery) when AC fails or is turned off. If
the AC is off for any length of time the charger alone can take down the
battery unless you use steering diodes on the output.
Commercial communication grade chargers are highly filtered, highly
regulated, temperature compensated, and isolated from the load. They are
also highly priced.
Astron makes fine DC power supplies that are well filtered and well
regulated. If you choose to use one to float batteries I suggest you get
one with adjustable output voltage and make sure it is isolated from the
load. I lieu of a motorcycle battery, I suggest you get a deep cycle
trolling motor type battery (Sears has a deep cycle Die Hard) which probably
won't cost more than a motorcycle battery and will give you much more
standby time.
Or, you could go to Office Depot and buy the biggest, baddest UPS they sell,
and plug your RS-35M into it. Good luck....
73, Mac K6YS
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