Back-Up Power - Question

[frankandmaura]

Hey all...the age old fear, power outage

I am looking for something that will sustain a powerhead for a day or so...

Something simple, that I can just plug in and will give me some piece of mind and water movement. I would like to keep one of my Hydor 4's running (they are like 8W).

How would something like this work? How long would it keep my PH going?

http://www.upsforless.com/index.asp?PageAction=VIEWPROD&ProdID=32&HS=1

I am not looking for something I have to jerry-rig, boat battery, etc...

Thanks...

 

[Conesus_Kid]

Batteries & Runtime

* Typical recharge time 5.70 hour(s)
* Replacement battery cartridge UBC7 Quantity 1
* Typical Backup Time at Half Load 22.1 minutes (475 Watts)
* Typical Backup Time at Full Load 6.0 minutes (950 Watts)

When I read this, it confuses me!

I'm no electrical guru, and there definitely doesn't seem to be a set proportion of watts vs. runtime.

Any EE's in the crowd here?

 

[frankandmaura]

Yeah, I was wondering the same thing...what constitutes half power or full power?

I was thinking if a Hydor is like 8W (hr) - I think that is what that means...and this thing holds 950W of power, then this thing should run a Hydor for like almost 5 days (118 hours - can that be right?).

 

[fatrip]

it would be 118 mins not hrs. at an expotential rate of 16.9 mins per halfing the power. getting down to 7.425w would equal 123.6 mins which is roughly 2 hours. not a good idea...get a small cheep generator or a 12v inverter and pull you truck around the back side of the house and run an extention cord threw the window.

 

[frankandmaura]

How is it 118 mins?? The hydor runs 8w/hr (correct)??

950/8 = 118 hours

 

[fatrip]

yes. lol...i hate math... if at 950w you get 6 mins and at 475w you get 22.1 mins. if you keep having the power intil you get down to 8 watts and you keep adding to the time buy 16.9 mins which if it is an expotential regression would give you 123.6 mins at 7.425 watts.

 

[fatrip]

sorry it progresses the mins by 16.1 each time not 16.9 and at 7.425watts it would be 118.7 mins. little early to do math...lol..

 

[fatrip]

see i told you it was to early for math....i F'ed it up agian...this is correct...if the UPS regesses at an expotential rate at 8w you should get a little less than 2050.7 mins or 34.18 hrs. srry i screwed it all up for you at first. so
if 950w=6min
475w=22.1min
237.5w=54.3min
xxxxxx=xxxxxx
7.425w=2050.7min

 

[frankandmaura]

So...a day and a half isn't bad, right?

 

[fatrip]

not bad for short simple outtages but what if the eastern seaboard goes down again...lol...

 

[fatrip]

now you got me freakin out frank thanks...i'll be away till monday. if the power goes out some one wanna give me a call...lol...i hate you frank....

 

[frankandmaura]

Sorry man...we are all very vulnerable...when we had the flood I was down for 3 days. I didn't have anything in the tank, but if I did I would have been dead. I don't want a friggin big, noisy generator though...

 

[fatrip]

lol you have the perfect set up for it though...all you have to do is put an outlet on the outisde back of you house and run it to the back of the tank...maybe 20 bucks in materials. then just make a small dog shed for the generator and just plug it in when you need it...

it would be much appreciated if you could call me if the power goes out tho......it will be a mad rush from the Island but i should make it in under 4 hours...nothing should die...knock on wood...lol...

 

[frankandmaura]

I sure will...I highly doubt we would have any issues, there is no bad weather predicted. One problem...I may not know if the power goes out in Binghamton, but I can sure call you if I hear something or if I lose my power.

 

[fatrip]

lol yea i know...thanks...

 

[frankandmaura]

<a href=showthread.php?s=&postid=12598182#post12598182 target=_blank>Originally posted</a> by fatrip
see i told you it was to early for math....i F'ed it up agian...this is correct...if the UPS regesses at an expotential rate at 8w you should get a little less than 2050.7 mins or 34.18 hrs. srry i screwed it all up for you at first. so
if 950w=6min
475w=22.1min
237.5w=54.3min
xxxxxx=xxxxxx
7.425w=2050.7min

Sorry...can you show me the rest of the math?? I don't get how you get to 2050 mins??

if 950w = 6min
475w = 22.1min (6+16.1)
237.5w = 54.3min (6+(16.1*2))
118.75w =
59.38w =
29.69w =
14.84w =
7.42w = 2050.7min

 

[fatrip]

lol ok i'll try...if the battery degrades expodentially...(in equal perportions)...we can start with the 2 we are given...if 950w = 6mins and 475w (which is half of 950w) = 22.1m this would mean that the rate of increase for halfing the wattage is 16.1m. since you are halfing the wattage you need to double the mins that it adds to it. so at half of 475w is 237.5w you would double the 16.1m to 32.2m and add that to the 22.1 that you have to get 54.3mins...and then you just keep going...the next would be adding 64.4m to the 54.3mins you already have...do you get it now??? im not sure if i can explain it better than that...lol...

 

[frankandmaura]

Ok...I get it now...sorry for being thick this morning!

 

[fatrip]

its aight i am surprised i could explain it that well before 12 oclock...lol

 

[frankandmaura]

LOL...ok...I am really not trying to be a pain, just trying to understand...

if 950w = 6 min
475w = 22.1 min (6+16.1)
237.5w = 54.3 min (22.1+32.2)
118.75w = 118.7 min(54.3+64.4)
59.38w = 247.5 min (118.7+128.8)
29.69w = 505.1 min (247.5+257.6)
14.84w = 1020.3 min (505.1+515.2)
7.42w = 2050.7 min (1020.3+1030.4)

Ok...I got it!!