200w

at_b · 01-03-2004, 09:06 PM

would a 500va UPS be able to give around 150-200W of power if it s battery is connected with the car s battery while the engine is working?(in a tank like setup, relay driven). could it work if replaced with a better battery?

I read all the threads ups related here, and i already know about the downsides and so on...but it seems a much cleaner alternative this way.
Regarding the ups s not being designed to run for a long time...wouldn t that be solved by effective cooling?...i won t back out to tearing it appart to make it fit for this pourpose...so some of the previously raised problems aren't significant.

Please give me feedback on this idea as i m damn poor with math and formulas that i would need to know in order to find out for myself

robiewp · 01-03-2004, 10:51 PM

the short answer is yes. I don't want to give you a long answer, because somebody will undoubtedly ***** about the exceptions. in a perfect world it could support 500watts of draw.

Ricky327 · 01-04-2004, 12:21 AM

the short answer is yes. I don't want to give you a long answer, because somebody will undoubtedly ***** about the exceptions.

Jackso · 01-04-2004, 12:29 AM

the only real problem you might encounter is whether the UPS will run properly with 13.6 volts applied to it. That and the cooling that you mentioned.

at_b · 01-04-2004, 04:59 AM

yup...forgot to mention the regulated 12V...
well...i must now find something to regulate around 20 amps if i m not mistakin to 12 volts
i m not intrested in cranking survival...although, with a little care while building the setup it might just do that too...sice it will have an aditional battery which could withstand power several mins...

hey...since it s a rather large 12 volt rechargeable in the ups...wouldn t it require something like 13+ volts to charge?(gues it s notthe same thing as there aren t applied 13 volts to the ups's while it s powering from the batt)

thank you people for all your responses...if you have any more suggestions don t hold them back

...and robiewp...i noticed that in a lot of threads...the *****ing about exceptions on and on...i waas close to ditching the idea, based on ups-as-inverter related threads, but i saw in some other threads, related to something else that there were ppl actually using it...some of them for some time...my problems were if it was able to withstand the current draw for 200W+...now all i have to worry is the car battery since i think i have a small 35Ah...

thanks

Jackso · 01-04-2004, 10:12 PM

right, once you're running off of the battery, there is no voltage being applied to it. So even if it were to require 13 volts to charge, the inverter would be using 12v. It may work fine at a higher voltage, but I'm not sure. I'd test it with a lightbulb and a meter before I hooked it to anything sensitive.

at_b · 01-05-2004, 11:40 AM

ok
thanks people
i ll do some test tomorrow

and let you know

robiewp · 01-05-2004, 12:08 PM

I still don't quite understand why you would want to do this, other than the shutdown controller (which i think you could likely butcher). A good inverter that will handle 10-15v input, along with a 2nd battery in some sort of a tank circuit would be cheaper (in my opinion), and better.

at_b · 01-05-2004, 01:36 PM

Quote: Originally Posted by robiewp

I still don't quite understand why you would want to do this, other than the shutdown controller (which i think you could likely butcher). A good inverter that will handle 10-15v input, along with a 2nd battery in some sort of a tank circuit would be cheaper (in my opinion), and better.

i can get ups's cheaper than an inverter, higher powered too
also, i guess that the (pseudo)sine wave outputed by the inverter(a good one) would be of a much higher quality

robiewp · 01-05-2004, 09:12 PM

Quote: Originally Posted by at_b

i guess that the (pseudo)sine wave outputed by the inverter(a good one) would be of a much higher quality

I didn't realize that would matter, but you're probably right. When I get back on campus I'll check it out.

"excuse me sir... where are you going with that oscilloscope?*

at_b · 01-06-2004, 01:18 AM

Quote: Originally Posted by robiewp

I didn't realize that would matter, but you're probably right. When I get back on campus I'll check it out.

"excuse me sir... where are you going with that oscilloscope?*

lol

thanks man

i m getting the ups today, maybe test it later today