While you are probably thinking this project will be hard to do, let's start
with just the base idea....
Let's just build the alternate power supply...
Well, since UPS circuits would be a bit complex to design, I'll cover that in
part two of this guide. But let's cover how to make the first part, which you
can use with... or without a UPS. Since an "alternate power supply" refers to
the batteries inside of the UPS unit... guess what I'm referring to when I say
the same thing.
The batteries inside of the standard UPS are "sealed lead acid" type
batteries which are sealed in nature and offer better safety to the consumer
than the standard wet cells that we use in our cars, boats and other vehicles.
Contrary to popular belief, the liquid that you see in wet cell batteries is
not strong acid. It is usually a diluted mix of sulfuric acid and water that is
put in at either point of purchase or at the factory. The acid which is in the
water usually soaks into the lead plates, causing the chemical reaction which
creates and stores energy.
This doesn't mean that it still won't burn or hurt you... because it will.
But if you get some on your hands, your skin won't melt into a puddle either.
Believe me because I've had allot of acid on my hands and they aren't
deformed.... or so I've been told. haha
Anyway, I say this because I want you to understand that batteries are
dangerous. When charging, the wet cells we are going to use emit low levels of
hydrogen gas. This stuff is flammable. Now, I've seen many people smoke around
these things and know that they for the most part are safe, but please use some
caution and don't smoke right next to them.
This is the Yuasa 12volt, 7Ah (Amp hour) SLA (Sealed Lead Acid) Battery. In
most smaller UPS's, this is the battery that you will find when it comes time to
replace them. These batteries usually cost around $22-30 each and last 3 to 5
years. For something comparable to the wet cell below, you'll pay something like
$200 to $400. Why? Because this battery, unlike the one below, can be mounted in
any environment, at any angle and without fear of leakage or explosive gas
This is what we'll be using... Well, close anyways. See the difference? If
you turned this battery upside you'd have a big mess. So please, don't try to do
that. And btw, sulfuric acid likes to eat cotton so please don't wear clothes
that you care about when doing this project. Because polyester is plastic based,
it is safe clothing to wear. But please realize we aren't liable for you
destroying your clothes of course. Oh yea... and I shouldn't have to tell anyone
this, but please do not mess with batteries without wearing anything.... it
burns, okay? 'Enough said? haha