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ergo_sum 10-10-2005 08:29 PM

alternate power source
Hello All:

I'm anticipating power outages of more than an hour a day.
I need an alternate power source that allows me to access the internet, and, regrettably, the power inverters that I've looked at don't allow for internet acces. Gasoline or diesel power plants do allow for access, but sticking one on a balcony is not an option (too much noise and exhaust).
Is there a power inverter or alternate power source that will allow for internet access?

All relevant replies greatly appreciated.


Matir 10-10-2005 09:17 PM

In what context do you mean "allows me to access the internet"? Any power source should be the same if it gives you the proper output.

In what way did some options not work?

michaelk 10-10-2005 09:26 PM

How much is more then an hour?
I don't understand why any power inverter limits internet access.

1. Use a laptop instead of a desktop. A fully charged battery on a modern laptop should last more than an hour.

2. Purchase a UPS rated for network / office use. This will provide an increased run time with just a single desktop. The higher the output capacity the longer you will be able to run. Some UPS allow for extra batteries.

3. Any DC- AC power inverter that is rated for the power required by your PC will work. It is the rating and type of the battery that is important. For example a 100 AH battery will last 10 hours with a 10amp load. A deep cycle battery like ones used in marine applications are recommended. You will need some additional electronics if you want to automatically switch between line source and the battery. This is basically the same thing as an UPS.

ergo_sum 10-10-2005 09:27 PM

Well, if you've been on an alternate power source you'd know.
Some convertors do not supply the proper electrical current and you won't be able to even boot up.
I know very little about electricity but I believe most will give you a sine current (wavy), as opposed to the current that looks like this: n_n_n or blocky.
Blocky juice won't let you even boot up, and, all of the converters I've tried will let you boot but not let you access the internet.
I don't know if it's a modem deal or an inverter deal or what.

Anyway, I'm looking for answers.

Matir 10-10-2005 09:50 PM


I could understand a cheap inverter not allowing you to boot (unclean power) but if your computer works, there is absolutely no reason you should not be able to get online.

What happens when you try to get online?

And if the inverter is no good... why not get a better inverter? From what I've seen, most inverters give better AC than small generators, which are usually not designed for electronics as much as power tools and work lights.

ergo_sum 10-10-2005 10:06 PM

Modems are very much attuned to electricity. Any linux person having a lin-modem knows this.
Maybe a real modem instead of a linmodem would help. But I need knowledgeable replies, given from experience, not knowledgeable people who haven't experienced the problem or really know about it.

We're not talking "cheap" converters, nor "unclean power", whatever that is.
What I have posted as my problem is very real, as anyone w/ daily power outages can probably confirm.
So I want to alleviate this problem I have.


michaelk 10-10-2005 10:26 PM

The cheaper inverters will produce a square wave i.e. modified sine wave instead of a true sine wave.

You want a power inverter that produces a true sine wave and that is rated for at least 20% or more for your anticipated load.

These inverters have true sine wave outputs and a low total harmonic distoration rating.

If the continuous output rating and / or the surge rating of the inverter is not high enough then your PC will not boot. It is difficult to tell why your modem may not be functioning correctly.

ergo_sum 10-10-2005 10:54 PM

Well thanks for that.
I've been thinking that since I have a linmodem maybe a true hardware modem might help.
What I'm really looking for is an alternative power solution.
Is there a UPS that will give me more than 5 mins of power?

Matir 10-10-2005 11:34 PM

There are plenty of UPSes that will give far more than 5 minutes of power. I get ~35 minutes out of the one for my desktop.

michaelk 10-10-2005 11:34 PM

linmodems are usually internal PCI devices and their power is provided by the power supply unit (PSU) of the computer. So it is either because they are cheap or that the PSU does not like the output of the inverter. IMHO a cheap hardware modem will probably behave the same.


Is there a UPS that will give me more than 5 mins of power?
Sure. The higher the rating the longer the run time. APC model numbers are usually the Volt Amp rating of the unit. example. A PC with with a 400 watt power supply will run approx 7 min. with a 750VA UPS and 1.5 hours with a 3000VA unit. These are APC numbers from their website. It just a matter of rating vs load.

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