Wednesday, December 07, 2005

Misc notes

Now I'm getting somewhere! I've been scanning lots of slide over the past month or so. I've done about 1000 of the Larsen slides and 700 Hemsworth slides. It's slow, but it's going.

I like stuff like this" IVR Cheat Sheet(tm) by Paul English. This guy took the time to compile a list of what to hit to get to a live operator instead of having to hit numbers and go in circles. He lists quite a few large companies.

I've also been testing more batteries - I've got about 120 that I've been working with (not all of them tested yet though). The BYU Amateur Radio Club (BYUARC) has been collecting batteries for me to test. I'm going as fast as I can. Whatever batteries test good will go back to the club for their members to use with their radios. So far, I've found that their batteries are doing relatively well compared to the ones I've been using (which have been about 50-50). I still need to learn how to test at a higher rate to determine if a battery is good or not without having to wait overnight.

Friday, November 11, 2005

Hemsworth slides

OK, I've started doing a few of my Grampa Hemsworth's slides along with the one's I'm doing for my wife's family. The scanner I'm using is a pretty decent one (prices finally came down enough!) that my M-in-Law bought to use to scan her slides. Since I have the scanner at my house, a side benefit is that I get to use it to scan my stuff as well.

Some of these are pretty old. The first slide in the first tray is a picture of my grandparents on their wedding day in May of 1939. As expected, there are quite a few of my mother and her siblings as well.

I'll get through these, but it will take me some time!

Monday, November 07, 2005

Progress report


I haven't taken Itok out for a run in a while and it's probably going to rain tonight and for a few days this week. He did get out in the front yard on Saturday while we were cleaning the garage. I thought he would stick around and play with us, but instead, he took off running (he LOVES to run). Taylor and Bryce spent about 15 minutes chasing him down. He didn't even act the least bit sorry for running off. He's going to learn how to come to a whistle no matter how many bags of doggie treats (or hot dogs) it takes!

Slide Scanning

I've done 20 boxes now for a total of just under 1000 slides (a few weren't completely full). I also scanned a bunch of documents that Janice's mom had on her pioneer ancestors that we haven't seen yet. I had intended to read some of them today while we were in Logan babysitting, but we played with the kids instead. 13 more boxes and I can start on my Grampa Hemsworth's slides.

Furniture re-arrangement

The family room was the victim this month. We moved everything (including the piano). It seems a lot bigger now at least when you stand at one end and look down to the other end (there's nothing in the way anymore).


My PocketTracker worked fairly well today on our trip with my digipeater and with the one on Shepherd Peak up in Layton but none of the others in the area seem to know what to do with it. I'll have to bring it in and look at the programming. You can follow it here on

Battery testing is progressing

Ok, so we just got back from visiting friends in Logan. It's been a long day and I want to go to sleep but I have to put just one more battery on the CBA. I'm numbering each of the batteries that I test and I'm up to 77 with this last one that I'm doing for a friend.

So far, I've found that several of my main batteries (the ones I thought were reasonably good) are actually pretty much worthless (at least for more than a few Amp hours worth). I still have 4 or 5 more to gather and test for the first time (they're in use in various places), but I've gone through most of the rest now.

I also found out that some that I thought weren't that great test out like they're brand new. Of course there are some in between that aren't totally dead yet. Like the 100Ah behemoth that came out around 80Ah even though it's been sitting for 12 months.

Thursday, November 03, 2005

Mold your own ear piece

Steve (NV7V) just sent around this link: PodFitKit Home

Sure sounds a lot cheaper than paying a professional to come and do it for you. You can mess up quite a few times and still come out ahead!

Let me know if you or anyone you know trys it. (click the comments link)

Wednesday, November 02, 2005

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.

Tuesday, November 01, 2005

Discharge cut-off voltages for VRLA/SLA batteries

I learned today by reading the technical manual on Power-Sonic's VRLA/SLA batteries that they recommended the following cut-off voltages for batteries under load:

Load to Volts per cell = 12V equivalent @ 68 degrees F
0.05C (20 hour rate) to 1.75V/cell = 10.50V (Ah available = 100% of rated capacity)
0.10C (9 hour rate) to 1.75V/cell = 10.50V (Ah available = 90% of rated capacity)
0.20C (4 hour rate) to 1.75V/cell = 10.50V (Ah available = 80% of rated capacity)
0.33C* (2 hour rate) to 1.67V/cell = 10.00V (Ah available = 72% of rated capacity)
0.50C (80 min rate) to 1.67V/cell = 10.00V (Ah available = 65% of rated capacity)
1.00C (33 min rate) to 1.50V/cell = 9.00V (Ah available = 55% of rated capacity)
2.00C (12 min rate) to 1.50V/cell = 9.00V (Ah available = 40% of rated capacity)
3.00C (7 min rate) to 1.37V/cell = 8.22V (Ah available = 36% of rated capacity)

*This rating was not in the data from Power-Sonic - I estimated it based on the other values because I needed a load value between .2C and .5C.

Of course other manufacturers will have somewhat different specifications, but I think these are pretty reasonable numbers and I intend to use them on future tests of VRLA/SLA batteries with my new battery analyzer in place of the default setting of 11.4V.

I also found the following interesting:

  • These recommendations cover batteries ranging from 0.5AH to 100.0Ah.
  • A 1C discharge rate reduces the Ah capacity rating to about 1/2 of the 20 hour rating (which is how most batteries are marketed).
  • A 3C discharge rate reduces the Ah capacity rating to about 1/3 of the 20 hour rate.
  • In the 400VA UPS units I have been modifying, 7Ah rated batteries were used. With a full load, this corresponds to a 3C discharge rate and should last about 7 minutes.
  • Replacing a 7Ah battery in a 400VA UPS with a battery* rated at 40Ah gives 70 minutes of run-time at full load. A 10x increase in run-time in exchange for a 6x increase in rated capacity.
*I often use multiple batteries in parallel.

Monday, October 31, 2005

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.

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.

Thursday, October 27, 2005

Got my CBA (battery tester)

I've been analyzing some batteries since I got my CBA II in the mail yesterday. I was going to do some work with commercial AA batteries, but I see that someone has already done it: CandlePowerForums - View Single Post - Alkaline Battery Shoot Out

So far, I have tested about 25 batteries including several 18650 cells from a Dell computer battery pack. I located a couple of bad cells from the pack and hope that after charging, the others will prove to be decent.

I found that my 50 Ah gell cell that I was using as an add-on battery for my UPS was only capable of delivering 12 Ah @ a 5 amp rate (pretty pathetic considering that in UPS service, it would be called on to produce 20-30 amps or so). Looks like I will be finding new batteries for the UPS. At a 2 Ah rate, this battery may serve well for someone in a dorm somewhere with a handheld radio - we'll see. I ran a test at 2 amps for a while list night, but gave up because it was still going this morning. I'll probably continue testing the smallest cells (and batteries) first and move up to the larger ones which take longer to test.

Charging is going to be painful - the only Li-Ion capable charger I have is a Maha MH-C777PLUS. It's a great charger, but it's going to be slow doing one cell at a time (the best way to analyze them individually). I guess that's OK, once they're all in packs, it won't be so bad ('till I need to break 'em apart to figure out which cell has died).

Tuesday, October 25, 2005

So, I have a blog now.

Wanna know what I'm up to? Don't rely on this! I doubt I'll be very consistent about keeping it up to date.

I have a few projects going on right now:

Battery testing - still waiting for the
CBA II to arrive.

  • I plan on testing all of the batteries in the truckload of UPS units I picked up from the giveaway at work. If any are good, I'll probably see if anyone in the BYU ham club would like to use them - they were going to do a project a while back, but ended up with a battery supply problem. As for the UPS units themselves, I'll try to pair them with good batteries and see if anyone in ARES wants them.
Slide scanning - I'm on box 17 out of 33.
  • There are 50 slides in each box.
  • I figured out recently that it takes me about 4 hours to scan each box (that's about 5 minutes per slide).
  • The newest version of VueScan has really made the Infrared cleaning work well on my Minolta D'Image 5400 II film scanner.
Sled dog training
  • Itok (short for Maniitok) has gone out twice now in harness.
  • He didn't have any trouble figuring out that I wanted him to pull me.
  • He wasn't worried in the least about this big heavy guy on a bike following him while he ran as fast as he could.
  • We inherited a 4 wheel "go-cart" from the neighbors - it has a two cylinder engine mounted on the back. I'm going to take it off - my engine will be connected by a tow rope. It's a heavy go-cart (probably a bit heavier than this one), but if he gets real strong, or I can recruit some other neighborhood dogs...
ISP Switch
  • I've given up on using Digis as my ISP. The high latency and packet loss were just too much to take with my VOIP telephone service. For normal web surfing, etc. they're fine (except I didn't really like the metered traffic business).
  • I hooked my network to my son's network and after pestering him to help me with IP address issues while he was trying to sleep last night, everything works great!
  • I may have some wireless equipment to sell soon. Actually, Andrew will probably end up using it and I won't get anything for it. Oh well...

Tuesday, October 11, 2005

Mortimer M. Clark

Here's a picture of one of my relative's (my 3G Grandfather actually) who I believe was born in Cleveland, Ohio. (Mortimer married Frances Marian McGLASHAN, daughter of Robert Peter McGLASHAN and Sarah HOLMES, on 19 Aug 1862 in Oronoco, Olmsted, MN). He died 20 Jun 1911, in Alberta, Canada

Photo of Mortimer M. Clark

This is an approximately 2" x 3" metal sheet with picture on it. Is it a tin-type? I really don't know. I've got a much higher resolution copy if anyone's interested.