CUSTOM UPS

[max3]

prehistory...
I was working all day yesterday including all last night on one project, spend close to 30 hours of constant work and today... cox sucking bastards shut electricity off... so i lost all my work... you peepz cant image how mad was i... it was also a few grand job that almost got done...almost...
Anyways, went to store got 1500VA UPS, which should give me about 3 hours of work offline, but that might be not enough, due to some projects require a lot of non stop computations, so PC cant be shut down.
Price for that UPS was 300$ they had same capacity but for 600$ just a bit more connectivity ports, which was not my primary concern. So came up with this idea to get real UPS, that would not make me spend 5000$ that i can earn doing something. so here it is:

Subj.
Has anyone tried to build one ? i am thinking of getting myself real UPS, that would allow me to continue working on whatever files for at least half a day or something.
First thoughts:
Get somewhat powerful UPS (a rackmount or any standalone unit that got decomissioned, take the old (bad) battery out and get a truck battery attached (you got it - may be even semi truck battery hehe )) there so many variants, main concern it has to be same voltage as original battery, i will probably will need to modify eeprom with charge current and maximum capacity but it should not be a big of a problem.
PERHAPS , SOMETHING LIKE THIS:
http://www.danplanet.com/home/81-hardware/111-custom-ups-external-battery-bank
Any comments are welcome, especially related to the subj.

[CPUShack]

really what you need is a medium size UPS to run the puter while the generator kicks in and warms up, then transfer over to the generator.

Tis how its done in most any critical infrastructure. No reason you couldn't do so at your home though

[doccybrown]

You`re on the right way, take a small or
medium cheap UPS with bad batterys and
wire some more powerfull big ones on it!
But be careful, use as many fuses as possible!
Those big batterys store so much energy
that a shorted circuit _will_ cause a very
hot and bright ball lightning
As long as the UPS can deliver enough
power to load the batterys it should work.
Of course the lifetime of the alternative batterys
will decrease a bit (because conforming pulsed hi-
current eliminates sulfation, I guess most modern
UPS do) but probably this effect is negligible as long
as you don`t take batterys that need a tenfold higher
ideal loading current. And afaik sulfation only
happens if a depleted lead acid battery
hangs around for hours not being used or loaded.
I'm using... erm... abusing an big APC rackmount version
to get the 24Volts for my led-lighting, router, alarm system
and some other gimmicks that need uninterrupted power.
Currently I am loading the original sized batts with the internal
UPS charger and a small windmill. This was a small project, the
next step will be bigger batts in my cellar, another second mill
and some solar panels on the roof

[doccybrown]

[CPUShack]

[Qwerty]

[JAC]

Ok... here is my 0.02$

Get a laptop.

All my primary work is done on a laptop now anyway, so no more bullshit with power outages.


Querty makes a valid point about the power quality of small generators... we have had various problems with our customers using them over the years. Surge strips are pretty much single use depending on the surge event.. active voltage limiting sockets are good, but the best way is to have clean power.

Again, there are many ways to hookup generators, batteries and the like, but this is what my dad did many years ago on a big sailboat ( ya, I did a lot of sailing and puked my guts out most of the time ).

small generator powering an industrial battery charger hooked to a huge bank of lead acid deep discharge "sealed" batteries. Hooked to the batteries we had a series of quality inverters. Power was distributed in the following ways...

24V DC - lighting. There was some 240V lighting but we only used that on shore power.
240V AC generator output to the galley ( microwave and oven, dishwasher, kettle etc..)
240V AC inverter outputs "clean" power, taken from the 24V to 240V inverters.

We actually had two generators, one was for the galley and the other as a spare. The battery chargers could be switched between generators.

[metalmaker]

A couple things. Be aware that the batteries used to start trucks are designed for short, rapid burst of power. Batteries for UPS are deep cycle, which means designed for lower power, longer operation. If you add batteries to a cheap UPS make sure and get deep cycle batteries.

UPS has two types of capacity - battery capacity (time) and current carrying capacity (power). You can add more batteries in parallel to original batteries to add time to a cheap UPS that has low power capacity. If you are only running your home computer, you do not need the high power of larger UPS, you just want more time.

The generator - Lots of people have a generator already at home - except they don't call it a generator - they call it a car. If you have a car, buy an inverter for the car and run an extension cord from the car to your computer before your cheap UPS runs out. Plug it into the back of the UPS so that the UPS conditions the power for the computer.

MM

[6a6ar09a]

If you need UPS for that purpose (computations) only, than the best way to go is; replace desktop with laptop. For amount ($300-$600) of money you mentioned, plus money after you sell desktop you use now.... you can get decent laptop plus extra battery (if needed). Clean and simple solution.
(Last couple of years I don't use desktop at all...)

If you need power for some other things... everything was already told... UPS, extra batteries, generator...
If you like or want to use renewable energy sources I can help with windmills. Like this for example; http://www.youtube.com/watch?v=5htzHADqxE8

One more idea, batteries from forklift, sometimes, can be found very cheaply and they are excellent for what you need.

[JAC]

ok.. I rarely act on the urge to respond to bullshit on the internet, but dude.. seriously..

[Barren Realms 007]

[max3]

[CPUShack]

In the ancient times of rubber battery cases, storing them on concrete (or any surface that could become moist an/or conduct) could cause them to discharge.

These days, with polypropylene cases, this is no longer a concern

[JAC]

[jrmunro]

I`m starting to feel the love here and can`t take any more of it.