Subject: The UPSer .FAQ File. Occasional Posting.
From: Bloody Viking <[email-masked]>
Date: Sat, 13 Nov 1999 23:11:59 GMT
Newsgroups: alt.energy.homepower,alt.energy.renewable,alt.solar.photovoltaic

The Modified UPS Frequently Asked Questions File. v.1.3

This .FAQ file concerns the act of modifying a computer Uninterruptible
Power Supply for the purpose of having a longer run-time or faster
charging or both. Essentially this covers the idea of taking a UPS and
modifying it in a way for protection for blackouts for emergency power. 

DISCLAIMER: The author/coder assumes no liability for any damages
resulting from the use, misuse, or abuse of the information contained
herein, nor for collateral damages resulting from the use, misuse, or
abuse thereof. This includes but not limited to equipment failures, lost
data, fires, or injuries. You use at your own risk. 

Now that the legal stuff is taken care of, I shall explain why I
wrote/coded this .FAQ file. Back in the summer of Y2K-2 (1998) in Chicago,
our power company warned the Chicago area that rolling blackouts may occur
as they had some nuke plants down for maintenance. Becuse my neighbourhood
had frequent blackouts I wasn't happy to say the least. Unlike the
Jobs(tm) thing, I decided to take matters into my own hands and build an
emergency power supply. I did just that. I over time (and some money
wastage) built a UPS that has 500 watts and can go for 3 hours. Not bad,
eh?

This .FAQ file is the result of my expierences with my machinery and my
time in alt.energy.homepower where off-grid power comes up as the topic.
As far as I know, I was the first one to intentionally buy a UPS for
consumer use to modify it for blackout-proofing. I was always a fan of
electrical technology. I always liked playing with electricity and I have
a decent safety record for my personal experimentation. Becuse I tend to
"fly by the seat of my pants" so to speak, it's good to know electricity
first! :) 

Q: How do you pronounce "UPS"?

A: I pronounce it like the pachage company, spelling it out, while many
computer professionals call it an "ups", as in "life has its ups and
downs". Both pronunciations are found in the computer world, in some cases
people will adopt the pronunciation used by the first person to bring it
up. Since I have an accent-control mechanism, in a room of computer
people, I use my pronunciation and others temporarily adopt it. 

Q: What's wrong with normal UPSes?

A: The average UPS for the average consumer is meant for a few minutes of
power, just enough to save a file then cut off the computer and the UPS.
If that's all you want, that's just fine. You can blow only $90 and get
one. You get like 10 minutes of power to the computer which is enough to
save a file and then some. As you can imagine, this wouldn't be useful for
those "mission-critical" mainframes or the like. But for most people, this
will work fine to save a file. However, this only saves the file. But what
about sitting around the house bored and sweaty?

Q: So what if you get sweaty?

A: Well, the UPS isn't a UPS, is it? That's why I own a 500 watter that
runs for hours! :) I can at least run a fan, as well as a light and my
computer... and my car stereo! 

There is in fact a medical reason I developed my UPS machinery. I have a
medical condition known as "hyperhidrosis". I get sweaty in certain areas
and as a result I always sought out cold to control it. I plan on getting
this fixed by surgery. Over time, I learned to shun heat, and my UPS is a
direct result of this medical problem. 

This same medical condition is causing me to develop low-energy-use
methods of keeping cool in blackouts, particularly the A/C Suit(tm) to be
used during blackouts with the UPS. Take someone into homepower, and add a
medical problem, and you will get innovation. It was this that caused me
to create this .FAQ file. 

Q: OK, I've got this 1,000 watter that has a dead battery and I like this
idea. How do I hook up bigger batteries to run for hours? 

A: This is why I wrote this .FAQ file. In my case I took an old 500 watt
UPS and modified it to use an external battery. First you need to find out
the original battery's voltage. In my case I was able to tell my UPS takes
24 volts. I examined the battery pack and figured it out. It took 4
batteries of 6 volts each in series. In early times with a cheap consumer
UPS I found it took a 12 volt battery by counting the seams of plastic
separating the lead-scid cells of the battery. Most UPSes use lead-acid
batteries much like a car but sealed. I took jumper cables and made holes
in the case and ran them to the battery in question. 

Q: Your current UPS takes 24 volts. How do you make it with batteries?

A: I hooked 2 12 volt marine/RV batteries in series and the UPS has the
jumpers coming out of the intentional holes. Thus, I clip the jumpers to
the 2 poles nicely. Come a blackout, it runs. 

Q: Aren't the batteries a lot bigger than the original?

A: Yes, by a large margin. By my extimates, about 6 times bigger if not
more. If I had the money, I'd expand it!

Q: Doen't the original charger not charge them up right?

A: Yes, that is a problem. This is why I use a car battery charger. 

Q: But wait! Doesn't your car charger only charge 12 volts not 24 volts?

A: Yes! That's why I devised a system using relays so as to charge each
battery one after a time. I use relays in my system to remote-control the
changing of the clips from one battery to the other. That way, I can
interface the car charger to the UPS for quicker charging after the
blackout. The only problem is that at this time I must manually control
the switches that control the relays in question. I have a third relay for
blackout simulation, controlled by a separate switch. 

Q: So, why do you like 24 volts?

A: There are two reasons. First, there's that current infrastructure where
I get 12 volt parts and that smaller wires are needed for 24 volts at a
given power. At 500 watts, you're talking 25 amps assuming some losses
while at 12 volts you need 50. Although I use jumper cable wiring, smaller
wire can be used at 25 amps and still not overheat. 

For battery charging, there's an issue of some UPSes being sensitive to
external chargers. With my setup, only half the battery cache is on charge
at any time. Cheap UPSes will often trip off if you apply external
charging. I adopted 24 volts as a standard as it's rather common and you
can by a centre-tap adapt 12 volt stuff. Just be careful about grounding.
:)

Q: Can you set up a bigger system for better run-time?

A: Yes, and I'm planning on upgrading. I want a run-time of 10 hours at
full power. That'll take care of the garden-variety blackouts nicely. It's
probably best to design for a full-power run-time of half a day at least.
Except for extreme cases, that'll handle most blackouts nicely. 

Q: Can you parallel batteries in a large battery bank?

A: Yes and no. When possible, it's best to avoid paralleling battery
caches. Instead, it's better to buy the batteries with the desired
amp-hour rating in the first place. For large ratings, you'll have to get
industrial batteries, like the ones used onboard electric forklifts. These
are some MASSIVE "muthuhs". One case where you have no choice but to
parallel is the case of an apartment dweller. After all, you have to get
the batteries up the stairs. Depending on your strength, a 70 pound cell
should be manmageable. For 24 volts, figure on carrying 12 cells up the
stairs to assemble the battery on-site. Future movers will HATE you! 

Q: Do landlords allow large batteries?

A: So far, us UPSers are rare, so the default Lease has nothing to prevent
it. This is unlike waterbeds, which most leases ban.

Q: What about the actual weight of the battery pack?

A: This is a good question. This is a good concern as it would be rather
embarassing to have your battery cache fall through the floor! Happily,
the average apartment will handle quite a bit of a weight load. For best
results, you place the battery cache against a load-bearing wall. The
average human weighs 200 pounds, and the average car battery or equivalent
weight battery will weigh 70 pounds. You get 3 batteries to the human, so
if you can have 5 humans you can have 15 batteries easally. :) The biggest
problem is getting the cache up the stairs (and later moving). Getting a
battery cache up the stairs in my case is the biggest limitation imposed
on my using this technology.

Q: What are the best UPSes/inverters to get?

A: I use the cheapest gear I can find, due to my chronic money shortage.
If you have a good money supply, you should get a clean sinewave inverter.
If you have a chronic money shortage, you will have to settle for a dirty
inverter/UPS. A dirty inverter means having to adjust to the requirement
of watching out what you buy however. Except for clocks (and things with
clocks) most stuff run fine on a dirty (modified sinewave) inverter. I
like dirty inverters but if I had a money well pumping out Susie B solid
dollars by the barrel I would go with a clean one. My UPS is very dirty,
40 HZ squarewave! 

Q: What is "clean" and "dirty" power?

A: Those terms are idiosyncratic to my use. I have a marked tendency to
use idiosyncratic language. Clean power refers to power that is correct
for your country (110VAC 60HZ sinewave for America) while dirty power is
anything outside of your country's specification. For Yanks, 110VAC 60HZ
squarewave is dirty as the waveform is incorrect. Off-frequency sinewave
is also "dirty power". 

Q: Do computers run on dirty power?

A: Yes. The average PC will work nicely on a dirty inverter. However,
beware of laser printers. Those like LOTS of clean power. If you can
afford a laser printer, chances are you can afford a clean inverter. 

Q: Do other things run on dirty power?

A: This depends on the dirty power in question! If it's on-frequency,
you'll be pleasantly surprised at the variety of thengs that will work.
Most things work fine on dirty power so long as it's on-frequency. Clocks
however will not work. That's becuse of the harmonics causing it to run
fast on a random basis. Electric engines run on dirty power but may get a
little warmer. If the frequency is off, they will however run slower (if
too low) or faster (if too high). Most modern inverters will be
on-frequency, however. Universal electric engines will run beautifully,
like incandescent light bulbs. 

An interesting note here involves the Navy and Europe. The Navy uses
electricity that is "double-hot" but is otherwise correct for American
power. For my purposes, it's dirty power. European electricity is
"double-hot" but is 220VAC 50HZ sinewave. Funny that a Navy ship would
flunk an electrical inspection! 

Q: Do Lead-Acid batteries have a "memory" problem like nickel-cadmium
(NiCd) batteries have?

A: Yes and no. Lead batteries do have a "barrier effect" when the lead
plates are spiked with antitomy. The type spiked with calcium do not have
a "barrier effect" problem. What happens is that as you keep a lead
battery float-charged a barrier builds up and upon the blackout the device
fails. This happens with cheap UPSes in a case of reasonably reliable
power. It also would happen onboard submarines were it not for the fact
that Navy people prevent it! What the Navy does is to have the batteries
discharge by a resistor and always charge it up again periodically. 

What I do is I purposely simulate a blackout once in a few months for a
short while then recharge immediately after the intentional discharge. I
call this a "dive". I thus exercise the battery cache and recharge to
maintain full blackout readiness. I also never float-charge batteries.
Upon completion of a "dive" I will recharge upon "surfacing". A typical
"dive" may be from anywhere from 15 minutes to an hour with my 3-hour
battery cache. I normally do this when I feel power is reliable so as to
know I can "surface". I took the Navy procedure as I found out in
sci.chem.electrochem.battery and adapted it for my UPS machinery. :) A
"dive" can be fun! :) I normally do a dive when I'm drinking on a Saturday
for some reason. 

Q: Can you use a microcontroller (i.e. a BASIC Stamp) to manage a battery
bank?

A: Yes, you can. You can even in theory solve the problem of paralleling
batteries in your cache. If you can programme in BASIC and interface the
embedded system to relays, you can do nearly anything. Although I havn't
done it yet as of coding this .FAQ I already know how to do it with my
present knowledge. I managed to interface relays to a Commodore 64 so as
to build a light show machine. I used to use the machinery for Christmas
light shows. All you have to do is get creative with the relays to manage
a battery cache. You will have to use automotive relays and interface it
with the embedded system. 

Q: Is there more information about UPS equipment?

A: Yes. There is a UPSer .FAQ written expressly for computer professionals
who are using the gear for the original intended purpose. It's much longer
than my UPSer .FAQ and is quite informative. That .FAQ doesn't cover
modification of UPS gear like this file does. It does discuss dirty and
clean power and software to be used on servers to cause auto-shutdown as
well. Pretty good for covering the intended use of UPS gear. 

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