Rework a UPS with Massive Capacity

Step 3: Connect the Battery / Batteries

Here's where you connect up the battery or batteries. Remember that the batteries are likely charged and can supply a LOT of current. I think there's another Instructable that tells how to use them for welding. You do NOT want to do any welding, so make all crimped connections before you connect them to the batteries!

If you have two batteries, make sure to cut a short piece of wire before you add the ring terminals to the other end of the wires you connected into the UPS wires in the previous step. Make sure that this jumper wire is not too short if you are putting the batteries in containers (see end of article).

Note: You might have to ream out the inside of the ring terminals if you could not find terminals with the right inside diameter.

Once you know that the ring terminals will fit, crimp them to the red and black wire ends. If you have two batteries, make the jumper with the other two ring terminals and the small piece of wire you cut off.

Connect the red wire to the positive terminal of one battery. Connect the short jumper between that battery's negative terminal and the positive terminal of the other battery. Then connect the black wire to the negative terminal of the second battery. If you do not connect them this way, you will not get any power into the UPS.

Comments

[dwltn]

These batteries are not sealed like the ones that came out of your UPS. This means that the gas produced when they are charged (hydrogen) will be released into your storage area. Use longer wires and place the batteries outside to prevent a possible explosion when you turn on a light. ( think Hindenburg)

[Surferdude]

This isn't a big problem.  It's only after discharge and amount depends upon charging efficiency.  The Hindenberg was filled with it.  This is a small amount and it dissipates in the air enough that it's not usually flammable unless you enclose it in a small volume that does not breathe.  You also would have to have a source of ignition.

[dwltn]

 The wire is pretty cheap. When we install large UPS systems (for data centers) we need direct forced air venting to the outside by code. You know someone's wife or girlfriend is going to make them hide it in a cabinet and close the door to keep the house presentable. Any switch or relay (present in some of the older systems) makes a great ignition source. Outside would be better. New sealed batteries start around 30$, new (and more efficient) units are in the $100 to $150 range. new house is in the 100,000 range. Caution and more caution  

[Surferdude]

Actually, new sealed batteries start at about 15 cents at Costco, in quantity.  But then again, AAs won't run your computer very long.  The point of the article was to extend the runtime of your UPS by adding a huge battery capacity at reasonable cost.

If it's in a closet, it's not likely to be plugged in - most closets don't have outlets and said wife, husband, girlfriend, or boyfriend that made you hide it isn't likely to want a thick cord running from a wall outlet into a closet, and then more cords coming out of the closet into a nearby computer, monitor, etc.

Caution yes.  OCD no.  If people read the article and comments and recognize the limits, they can avoid the pitfalls.  That's what this is all about.  You can find some hazard in just about everything posted here, but then you wouldn't do anything.

[pedxing]

please note that even unplugged, with the battery disconnected, you can get a nasty (perhaps fatal) zap from the capacitors inside the unit. Be very careful when working around the circuit board - don't touch anything but the insulated wires.

[osgeld]

For large terminals check out places that sell car audio

if you can find a place that sells this to the public

http://www.theinstallbay.com/product_section.php?pn=1

nothing special but cheap :)