thankfully we made it through the storm just fine here in south minneapple but it got me thinking nonetheless. especially seeing my reefing elders derek, david and everyone else in the north stuck...
i've had a deep cycle marine battery sitting in my garage for that one time a year i fire up the trolling motor. but i've never had a power inverter. so today i bit the bullet after doing a few calculations (that made it ever apparent what an asset the battery/inverter combo could be) and bought a cheap 12VDC->115/120VAC power inverter (target $30).
we've had this discussion before (
http://www.thereeftank.com/forums/sh...battery+backup )
and there are a number of options.
as far as turning on automatically you can go as cheap as $15 for the penn plax silent air B11
battery powered air pump. It is supposed to run in the neighborhood of 48 hours on a pair of D-cells. As with an old undergravel filter an air bubble can move a fair amount of water and facilitate air exchange. this one senses an interruption of power and switched on.
you can step up to the jehmco/tripp-lite aps ($300+ + batteries) which will allow you to power other pumps/accessories on your tank. power is supplied by marine
deep cycle batteries. the inverter/charger unit maintains the charge in the battery(s) and again senses power interruptions before firing up (UPS). david is running one of these and derek should be-by now as its been collecting dust in his basement and only needed a lil wiring work. i think this is an ideal backup system for outages less than a day or two but for longer durations you'll need to come up with "fresh" batteries.
the new option is whole house natural gas supplied backup generators. if you have the thousands up front to invest i'm sure they're wonderful.
NOW-if you're around and an automatic switch over isn't critical you have some other options.
alot of people will hook a power inverter up to their car battery. running the car every few hours should recharge the battery sufficiently and you're only limited by gas in the tank and the length of your extension cords.
std gas powered generators are another option. they can supply alot of power depending on their size and again you're really only limited by access to gasoline.
finally-what i'm gonna be doing...using the power inverter and a spare marine deep cycle battery. this webpage gives you some info about calculating run time off of finite source.
http://www.1st-optima-batteries.com/...plications.asp
in the event of an outage i would be running my Tunze Stream 6000 (11W max-will actually be lower because it will run in "night mode"-lower power)
11W*1.15 (~15% energy "wasted" in the inversion process) = 12.65W
12.65W / 120V = 0.105A
the die hard marine deep cycle battery i have (M24 series) is rated at 80AH (amp hours) @ 12V. as it is a 10 fold increase in voltage (from 12V -> 120V) we divide the AH rating by 10 to get 8.0 AH @ 120V.
now if we divide the 8.0 AH rating by the A draw of the Tunze 0.105A we get
76.1 Hours of run time. that's alot of time! obviously if you ran more energy intensive devices run time would be less but it gives you an idea about what can be done for about $100 (deep cycle battery + power inverter)(a little more if you don't already have a battery charger). Since my battery is a couple years old i'm not expecting it to hold a 100% charge...still its a decent option.
if you want to do your calculations below we can check it for ya!
hope this helps someone and wasn't too boring to read through
rich
Everything looks fine, though.
)
