Notes on UPS units from UCARES picnic give-away

Since so many UPS units (~30) found new homes at the recent UCARES picnic, and because I didn't get a chance to modify this batch to add Anderson Connectors or put labels on them, I thought it would be good to compile a short list of notes that may help anyone who ended up with one make good use of it.

• All of them are used. They all used to work. I don't know if they work now or not. If you ended up with one that doesn't work, let me know - I think I can get a few more and can trade you.
• I have used them to charge and maintain 12 volt SLA batteries that were rated from 7 to 100 amps.
• Multiple batteries can be floated from a single UPS.
• They will NOT power a radio bigger than an HT for an extended period.
• You can use batteries (while connected) with higher drain radios without problems as long as the batteries themselves can handle the load.
• They provide about 0.75 A of charging current. A large battery will take a LONG time to charge at this rate.
• They float at about 14.0 Volts. A little on the high side (at the expense of battery longevity), but keeps the batteries fully charged and ready for use should there be a call-out, etc.
• SLA batteries can be left connected to the UPS indefinitely. I would expect about 3-5 years of life (a guess, not a formula) from a brand new battery if left connected and never used.
• They will work as normal UPS units and can provide backup power to a computer, etc. Just be sure to use large enough leads to the battery(ies) (at least 12 ga for full rated capacity).
• To turn the units on when 120 Volt power is not available, press and hold the power button until the unit beeps, then release the button while it's beeping.

Some of my other posts that may be helpful:

• Stuff about UPSs
• UCARES training item about batteries
• Be careful - batteries can do bad things

Last, here's a close up picture of the way I have modified these UPS units to put connectors on them for convenient use with my batteries:

I drilled a 1/2" exit hole for the wires (which are just barely long enough if you cut the original connectors off right at the end). I used hot glue on this one, but that wasn't the best idea I've ever had. You can see that it is loose now (3 years later) and doesn't keep the wires from moving in the hole. A grommet would have been better, but they are a bit of a pain to install and thread the wires through. I have had better success with using kneadable epoxy putty and just pressing it into place into the hole and around the wires. You may also choose to leave the original internal wiring intact and simply tap into the lines to bring a longer connection out the back. This would allow you to use an internal battery if you want as well as an external one if needed. Keep the wires as short as possible. At its full rated load, this UPS can draw over 30 Amps.

UPS mods, Tree removal, etc.

Some pretty random stuff here (this isn't a single subject blog by any means)...

UPS modifications continue

I collected another dozen UPS units from the recycling center at work over the past year and converted them to use an external power source.

We gave away 6 of them at the Utah County ARES (UCARES) picnic last night.

They can be used as chargers (about 1 amp max) or maintainers (floats at about 14.0 volts) for almost any sealed lead acid (SLA) battery and also as Uninteruptible Power Supplies (funny huh, since they were originally intended for UPS use!) and as (semi) portable inverters*. Hopefully there will be a few more happy batteries in happy valley. I hope to get more, but never know what the winds of change will bring...

*You do have to know how to turn them on when the AC mains are off. Hold (don't push and release) the power button until it starts beeping. While it is still beeping, release it. It should turn on and, if the battery can provide enough power for the load, it should stay on.

Neighborhood cat killed

Itok killed another cat the other night. We found it lying in the grass the next morning. (I didn't include any pictures for this event.) It was completely intact with no blood showing on the outside. I think this is the third or fourth one now that hasn't survived (at least one did when it made it up a tree and I went out and saved it - at 1:30 in the morning!). He doesn't tear them up or anything, he seems to just play with them. Anything that runs is apparently fair game. I don't know why these cats come into our completely fenced (6 foot high all the way around) back yard, but I guess they just can't help it.

People, don't let your cats run around - they get into my bushes and flower beds and use them as a litter box! If they come in my backyard (as they seem prone to do), they'll probably die.

Tree removal

When we moved into our West facing house 11 years ago, the front lawn was barren, so we planted a tree - a Navajo Globe Willow.



We loved it. It grew fast covered the entire front of our house with shade, gave the kids a place to swing, we hung a hammock from it for a number of years, etc. Unfortunately, Willows are generally considered "trash trees" because they drop a lot of junk in your yard. This one was no exception. Two or three years ago, wind took off a chunk of it and it took quite a while for us to cut it up and haul it away. It didn't seem to hurt the tree much (you couldn't even tell from the road in front because the tree was so big) other than the place on the trunk. Well, Sunday, the wind took off another piece of it and since it has been smelling funny (people tell me they tend to do that when they get old or infected), it was time to take the whole thing out.



It was quite a job and I'm quite sunburned. Luckily, a neighbor around the corner was having a tree removed the same day (for some reason I didn't think they'd be working on Labor Day) and I was able to convince them to let me pay them to haul my mess away and grind the stump down. Since I had felled it and cut it up already, it was a relatively small job for them even though the tree completely filled their 8 ton truck.



I'm glad that's over!

Another Li-Ion recall and a new battery technology announcement

Bad news first: Lenovo and IBM announced a recall of another half million (500,000) Lithium based batteries manufactured by Sony. It seems that after one flamed out at LAX last month, they got the CSPC involved.

Good news last: We may be using the acronym ZMP a lot more in the near future. Zinc Matrix Power has announced their Silver-Zinc rechargeable battery that supposedly has twice the energy-to-weight ratio as current Lithium based offerings without the explosive side effects or transport limitations. They have a low enough internal resistance that a relatively low number (16, producing 20 volts) were used to produce 80 amps to MIG weld two pieces of 1/8" steel (article reference).

In other not so interesting news...

• I finally got those surplus UPS units converted and we gave most of them away (along with the power conditioners) at the annual Utah County ARES picnic earlier this month. Hopefully they're all set up with some Sealed Lead Acid batteries that have been neglected for too long. If anyone wants help converting a UPS into an SLA battery maintainer, let me know.
• We were at a wedding reception for my niece a few weeks ago and came out to find a note on our car apologizing for the alterations done to the front bumper. The estimate was $402 so we might not even want to bother the insurance companies.
• Last week, I took the boys to the Orem Rec Center to play racquetball. The next morning, one of us noticed another alteration that had been done to the right rear pillar above the window. We have no idea how it could have happened unless someone dropped something off a truck parked next to us or something. That one will cost more than the deductible; unfortunately, we'll have to get the insurance involved. They won't be thrilled after the bike rack incident earlier this summer...
• We ditched the VoIP phone service we had from ACN Digital. Their equipment didn't work right (QOS was horrible, telephone adapter lockups, etc.) and their customer service was pretty much non-existent. My sister and her family were on it as well and like us, they decided to pay the cancellation fee rather than keep it. If you're going to go with VoIP, choose Vonage, they were good for us - we only switched to ACN to try to help a relative who was making a commission on the sale. We decided to go to cell phones instead (I couldn't bear to go back to a land-line provider).
• On that note, I also switched to a new LG LX-550 Fusic phone (Sprint Review - C|Net Review)from Sprint. I like it, but there are some things from my Motorola V-360 that I'll miss. Best about it is the signal is much stronger at my house because the transmitter is just down the street (there are 3 big "flagpoles" at the Junior High about 2 blocks away) and we can get a signal downstairs. Worst is that the MP3 player is still poorly integrated with the phone operations (I can't make an outgoing call while it's playing, nor does it resume after I finish with an incoming call). All in all, I think it's a slight improvement, but nothing to get too excited about.
  

UPS waveform article

Saw this article about waveforms from UPS units today and since all 16 of the APC-650 units I have are exactly what is shown in this article, I thought I'd link over to it. I have experienced problems with running UPS units from my small portable generator before, so now I want to go check it out a little and see if I can determine why. Just need to find someone with a scope and some time...

Jesse (the author of the article I mentioned) has also written about a UPS modification he did.

I have a couple of power conditioners from someone who didn't want to bother trying to surplus them. Never had a use for them before, but perhaps now I do! These are the type that claim to create clean power from dirty. They are quite heavy. I want to see if putting them between the generator and the UPS units clears up the problems I have seen in the past. I'll update this article with a model number and a link when I can.

FWIW, I have one of these 110 <-> 220 Step Up / Step Down Transformer / Voltage Conversion units too but I have absolutly no use for it that I can fathom right now. I'm pretty sure it's a model UDC-1500. If anybody locally needs one, you know who to ask!

More UPS units

Since the power outage I blogged about a while back the power has gone out a couple more times and I have inherited (for a small fee an IT auction last month :) several UPS units that are no longer welcome at the company. I need to get them home, remove the batteries, test them, and modify the good ones like I described earlier. Any good ones will be available to the amateur radio community here in Utah County.

These are all 650VA units like this only black. I would be willing to bet that most of them are perfectly operational and that the batteries are just worn out.

If anyone local knows of small personal UPS units like these (I'm not interested in large data center units) that are no longer welcome in their present homes, add a comment here to let me know and I'll do my best to give them a new lease on life.

UPSs save the day

Well, okay, not my whole day, but put together they saved my group at work an awful lot of time today. The power went out this afternoon while I had several long processes running and at least 15 edit windows open (with various stages of unsaved work). While some people here have all of their stuff (typically two 21" CRT monitors and a CPU) plugged into one 800VA UPS, I had the foresight to horde enough older units that I could plug each component into its own UPS (I have a 650VA unit for each monitor and a 1000VA hidden behind the filing cabinet for the CPU :).

The power was out for about 30 minutes. Both of my monitor UPS units died (one after 10, and the other after about 20 minutes), but my CPU stayed up (along with my work). Most people were at least able to save their work (they lasted 10 minutes or so). Sure makes me wonder why some people think that UPS units are not worth what we pay for them...

Voltage set points on modified APC UPS units

I have noticed now that I have modified about 8 of these units that when they are attached to a battery, they float at different voltages depending on whether the main power switch is on or off.

Typically, the powered ON voltage is adjusted for about 13.8V (a good voltage to float most VRLA batteries). However, the powered OFF voltage jumps by up to 0.5V. This is a little high to float at for lengthy periods, but shouldn't hurt anything if left for a day or so. In fact, it may be helpful to let a battery float for a little while at this voltage to help equalize the individual cells. A fully charged 18Ah battery that had been floating at 13.8V drew only 60mA or so for a couple of minutes before dropping to less than 10mA when it reached 14.3V.

Float voltage adjustment

It's also interesting that the charge rates are different depending on the power switch. With the power switch ON, these units will charge a nearly dead battery at about 350mA. With the power switch OFF it charges at around 400mA. While this isn't exactly a fast charge for an 18Ah battery, it is plenty to maintain a bank of batteries in an always ready state. If you intend to charge batteries with one of these units, I would only count on about 5Ah a day.

Multi-purpose UPS modifications

So, I've been modifying some UPS units and thought others might like to do it. 120VAC can kill you, so don't try this if you're not prepared or are unsure about what you're doing!

I procured a bunch of old UPS units (mostly like these) from my employer who did not want to maintain them anymore. The batteries were ALL completely dead, but the units themselves were just fine. I suspect that quite a few units like these are in similar circumstances - they don't work, and companies are happy to get rid of them so they can get newer technology (higher current ratings, USB connections, etc.).

Anyway, what I've done is to modify them to accept battery power from an external source. This makes them quite versatile and useful to anyone who uses 12 volt batteries for more than just powering a UPS. I use mine for powering many devices, not the least of which are my radios.

With the modification, my UPS units now keep my batteries charged (they float at 13.8 volts and that is usually adjustable). In the event of a power failure, they use the batteries that are attached to them to provide backup power to devices plugged into them (my computer for example). Attaching multiple or large batteries allows the UPS to provide power for longer than it would with just the internal battery. Most of them allow me to use them just like an inverter (provide 120 V AC power to devices when camping, etc.) when not plugged into utility power.

The APC units that I've been working with will charge batteries at a pretty low rate (I still need to measure with dead and fully charged batteries). They're not fast chargers by any means but they should be able to juice up a small 7 Ah battery in a day or so.

More UPS mod pictures available here

Here are the basic ideas:

• Plug it in and see if it comes on and will power a device. If this is a new-to-you device, it's nice to know if it works properly except for having a dead battery.
  
• Now unplug the thing and get to work. (You got this part without my help right?)
  
• Remove the dead battery. On units less than 5-6 years old, there's almost always a battery access panel. It is dead right? Even so, try not to short circuit it just in case the UPS circuitry is the problem and the battery is healthy.
  
• Turn the power switch on and fiddle with the buttons (mine will usually let out a dying wail as the capacitors discharge completely).
• Find a way to get the wires that attached to the battery out through the case so you can connect other batteries to the unit.
• Remove the existing connectors.
• Connect an extension wire to the short ones that are left in the unit. I have been working on 400-650 VA UPS units and have found that 12 gauge copper wire (like this) works great. You'll definitely want to keep the runs as short as possible (at max draw, a 650 VA UPS can pull 33 amps at 12 volts). 12 gauge copper wire is rated at 30 amps at 12 volts, so be sure to not overload it if you have a larger UPS that could pull more that that at full load.
  
• Drill a hole somewhere in the case.
• Feed the wire through the hole (with a grommet installed to protect the wire).
• Close up the case.
  
• Attach a connector to the wire. I use 30 amp Anderson Power Pole connectors. Of course, your battery should also have the same connectors on it. It would be good to have a fuse on the battery. Many UPS units have internal fuses (the APC ones I'm using have a 40 amp fuse soldered right onto their main circuit board).
  
• Plug in the UPS.
  
• Turn it on.
• Check the voltage at the connector to make sure you got the polarity right and that it is what you are expecting.
• You may want to unplug the unit from the wall or at least turn the unit off before connecting a battery. You may not need to do this, but the first time you test a newly modified unit, it's probably a good idea. Note that some units will keep the battery charge circuit energized while the UPS is switched OFF.
• Connect a battery. You will want to use a Sealed Lead Acid (Gell or AGM) battery only as the charging circuitry is designed for them. Using a flooded battery like you would use in a car, boat, etc. will not work as well unless you adjust the voltage of the charger.
  
• Plug in the UPS.
• Turn it on.
• Check the voltage at the battery to make sure it is what you expect.

So, for not a whole lot of money, you can get an older UPS unit that does all of this:

• UPS
• 12 volt Sealed Lead Acid battery charger
• Inverter
  

Great reading material on batteries is available at Battery University.