How do you build a backup power supply
Jonah Wamboldt
out. Could you use a 12v car bettery with a ac/dc converter? I was jsut
wondering if anyone has ever done something like this?. I know theres ups
but what i can read, They only last like 10-15 minutes?
Also, I built a new computer chair, The seat from the van is so perfect:)
Brian Smith
"Jonah Wamboldt" <wamb...@hfx.eastlink.ca> wrote in message
news:U0a5c.5845$kc2.1...@nnrp1.uunet.ca...
> Ok, I was having this crazy idea that I need backup power if the power
goes
> out. Could you use a 12v car bettery with a ac/dc converter? I was jsut
> wondering if anyone has ever done something like this?. I know theres ups
> but what i can read, They only last like 10-15 minutes?
Because of the acid in car batteries, I would not recommend using one
indoors, Jonah. Possibiliy of explosion is great , also.
> Also, I built a new computer chair, The seat from the van is so perfect:)
Have you consider a position with a Lazy Boy Factory? ;^)
--
Brian
www.accesswave.ca/~orion
ZOLOFT
Most UPS (Back Up) power supplies are not meant to run your computer for
extended periods when the power goes out. They are for saving open files
and shutting down your PC in a controlled manner.
I Bought a Belkin 500 VA UPS that powers my PC, Monitor (17"), Cable
Modem, and Wireless Router. (I did not bother with the powered speakers)
I get about 12-14 minutes of Back Up Power before "Battery Critical Low"
alarm comes in. This UPS came with a serial cable to tell the PC to
shut down after 5 Minutes (Adjustable). So, if I am not home the machine
will shut down normally. I bought it at Radio Shack for $99.00.
If you build your own, it is going to cost a lot more, and you will not
have communications between your back up and the PC. A 500 VA UPS is
about 300 watts of power. So, you will need an Inverter that can supply
at least that much, and a decent deep cycle (Marine) battery plus a
battery charger.
If you want to surf the 'Net in the dark or play games with the power
out, you are going to have to fork out some cash to do it.
Bill.
gman99
A UPS is not generally designed to run systems, they're designed to allow a
user to shut their systems down properly...
oldtrout
Hum I need to find some part time work, or rather I NEED a few more $.
Lazy Boy ....Man have I got the qualifications!
ot
Jimmbo
Yes lead acid batteries put off hydrogen gas you just have to have a well
vented room so they don't build up.
Then you need a batter, A marine deep cycle would be best. A 12 vold battery
charger. Now for the big thing. You'd want a BEEFY inverter. Which will cost
a lot :(
http://www.dansdata.com/diyups.htm
THe plus side of this one is that its always running off the inverter (which
also may be a down side)
Thats about all you need to know.
==Jimmbo
"Jonah Wamboldt" <wamb...@hfx.eastlink.ca> wrote in message
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Brian Smith
"oldtrout" <no-...@home.ca> wrote in message
news:e2bb509a5g0konh0o...@4ax.com...
>
> Lazy Boy ....Man have I got the qualifications!
Ha! Ha! I never would have said it, but, I'll sit here and agree with you
<g>.
--
Brian
www.accesswave.ca/~orion
Bill 2
"Jonah Wamboldt" <wamb...@hfx.eastlink.ca> wrote in message
news:U0a5c.5845$kc2.1...@nnrp1.uunet.ca...
You could get a UPS to provide 15 minutes of immediate power ($100), and
also wire an inverter up to a couple marine batteries. I've used a PC off of
a 300VA inverter and a car battery before, and the inverter cost $40 bucks
at Wal-Mart. A marine battery is like $80 at CTC. You'll also need a trickle
charger that can charge very slowly, as marine batteries need low charging
current. You'd use it like this: Power goes out, UPS runs system while you
plug in the inverter setup, plug UPS into inverter setup which will provide
power until NSP fixes the problem or you run out of juice.
The reason why you need a marine battery is that they can be used for full
charge / discharge cycles for dozens of times, while a car battery can't.
ZOLOFT
Inverter might be a little on the small side, better to go with a 500 VA
or a 750 VA!
Bill.
ZOLOFT
time how long you can run before the low battery alarm comes in. A 500
VA UPS should give you about 15 minutes + or - a couple of minutes. My
UPS (A Belkin) came with "Belkin Bulldog" monitoring software that tells
me the health of the battery and when I should replace it.
Bill.
Lucretia Borgia wrote:
>
>
> Would you say the information I was given, that as mine is about four
> years old, I should change it, would be correct ?
>
> Do they deteriorate with age ? It has been operational a few times
> when the power failed out here.
>
> Sheena
Jonah Wamboldt
600watt for ~120. For the autoshutoff, I'm not too interested anyways. I
can get a 12v guage which will let me know when shes going to go, I can also
all it in my case to make it look nice.
Also, For ups, they use a battery of some sort. Are they 12v? If they are,
couldnt you just run another 12v battery in parallel? or would it mess up
the charger part?
"ZOLOFT" <zol...@hotmail.com> wrote in message
news:zAm5c.6051$kc2.1...@nnrp1.uunet.ca...
Bill 2
audible alarm when the voltage gets low and display a warning light, and
will usually shut off at ~10V (to protect the cells.) This of course won't
gracefully close programs on the PC, it will simply stop supplying power.
As for UPSes it probably depends on the manufacture, it may be 12V, or it
may be 6V, but people do wire extra batteries in parallel and batteries are
available in both voltages. When the rolling blackouts were popular in
California, people paid to have enough capacity by wiring extra batteries
into a UPS. The only problem I see with this method is it would require a
lot of work to ensure it's safe. I'd hate to imagine what would happen if
the wires shorted out.
If the charging circuit was a worry, you could hook the marine batteries up
to an external charger after power is restored, and the internal charger is
probably good enough for a maintenance charge.
"Jonah Wamboldt" <wamb...@hfx.eastlink.ca> wrote in message
news:5%p5c.6159$kc2.1...@nnrp1.uunet.ca...
ZOLOFT
I am not sure if you understand the difference between a "Back up Power
Supply" and a UPS (Uninterruptible Power Supply) There is a BIG
difference. A back up system like you are thinking about is just for
using when the power goes out. A UPS system is designed to provide a
seamless transition to battery power with no bump or flicker of
current/voltage. That way the PC does not reboot and no data is lost.
The principle of a UPS in a nutshell is this:
AC Line--->Battery Charger--->Batteries--->Inverter--->AC Load (PC)
When the power is on, the battery charger floats the batteries AND
carries the entire load of the Inverter (Important). When the AC Line
power is lost the battery charger shuts down and the batteries start to
discharge through the inverter until they are exhausted, or the power is
restored.
Most Automotive battery chargers produce RAW DC with tons of 60Hz
ripple, but for charging a car battery that is fine, because the battery
its self acts like a filter capacitor. I seriously doubt that an
Inverter would handle Dirty DC current very well. Plus, the maximum
current draw of the inverter would have to be matched by the battery
charger in order to keep the batteries from going flat under load with
the charger in service.
If you simply want to have power available during an outage, a small
charger to charge up the battery is fine, BUT you would NOT be able to
use the Charger/Battery/Inverter setup as a UPS.
Another excellent reason to have a UPS supply for a computer is, you get
complete Isolation Protection from Line voltage Spikes, Surges,
Frequency issues, brown outs and even lightening! Most UPS companies
carry insurance to repair or replace equipment damaged by AC line
problems if in the rare event the UPS does fail to protect it.
Bill.
Bill 2
> Jonah,
>
> I am not sure if you understand the difference between a "Back up Power
> Supply" and a UPS (Uninterruptible Power Supply) There is a BIG
> difference. A back up system like you are thinking about is just for
> using when the power goes out. A UPS system is designed to provide a
> seamless transition to battery power with no bump or flicker of
> current/voltage. That way the PC does not reboot and no data is lost.
> The principle of a UPS in a nutshell is this:
>
> AC Line--->Battery Charger--->Batteries--->Inverter--->AC Load (PC)
>
> When the power is on, the battery charger floats the batteries AND
> carries the entire load of the Inverter (Important). When the AC Line
> power is lost the battery charger shuts down and the batteries start to
> discharge through the inverter until they are exhausted, or the power is
> restored.
You're thinking of high end true online UPSes. Those have expensive sine
inverters, experience reduced battery life, etc. The $100 ones you see at
futureshop, and most low end units (even most APC units), run on filtered
120V mains power and within a couple milliseconds of loosing power, having a
brownout, or overvoltage, switch over to internal quasi-sine wave inverter
power run off the battery. There is a couple milliseconds where there is no
power (this is listed in the specs for a UPS), and capacitors in the PSU,
etc carry over this momentary transition. For most consumer grade
electronics this is enough.
ZOLOFT
entire rooms and likewise has rooms just for the battery banks. BTW,
which are sooo cool!! The large Lead Acid battery banks produce 129 VDC
and are floated by huge battery chargers.
So what you are saying is that the inverter in my UPS is not supplying
AC until the power fails? According to BELKIN, the Transfer Time from
AC to Battery is 0 ms.
Thanks for the heads up.
Bill.
Joe Chiasson
converter. First the converter takes the AC turns it to DC this supplies
both the battery and the inverter, the inverter then takes the DC either
from the battery or the converter and inverts it back to AC! pretty much
0 ms.
ZOLOFT
BELKIN states and I quote: "Transfer Time - N/A" . That may be the
reason why my UPS is nice and warm all the time. I would think that the
battery charger would not be doing much if it was only floating charged
batteries. My laptop supply cools down to nothing once the batteries are
fully charged, even when you are running on AC.
Bill.