Tuesday, March 28, 2006

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...

Tuesday, March 21, 2006

Link added on VIP Bloggers

OK, so I'm not a VIP, (or a CEO, CTO, HMO, or anything else) nor do I think that I really have much on this page that people who come here from the VIPBloggers web site (first square on the second line) will want to read. Most of my ramblings are about battery chargers and other technical stuff that I have played with.

When I originally got the block of pixels on the site, I didn't even plan on linking back to this blog. I had it pointing at Paul Allen's blog and I was going to wait 'till I thought I had something worthwhile to link to. Like maybe the genealogy I've been working on, or the archive of information on converting old UPS units for Amateur Radio use (yeah, you don't want to miss it). Then Paul went and got his own space and his own link (the nerve!). So, anyway, here you are. Have at it...

Thursday, March 16, 2006

Charger "upgrade" disappointment

The Schumacher Speed Chargers are pretty similar in looks, but I have discovered that they do not all operate the same way. I'm disappointed in the upgrade I did when my previous one developed a bad fan. I expected too much I suppose. In going from the 12/25 to the 10/30, I was hoping to have a faster charger when I needed it (after all, 30 amps is more than 25!). I was hoping to be able to charge at a lower rate (10 amps is less than 12) when I needed to because it would be better on my smallish batteries. I was wrong on both counts.

My new charger operates in a single 10/30 mode, not two separate modes (10 or 30). I've actually measured the rates with my Whatt Meter and they are a little higher than the rated rates. The charger will start at a 12 amp rate as it checks the battery to see how it is responding. Then ramps up to 34 amps if it thinks it's doing OK. It will stay at the 34 amp rate for 1.5 minutes or so, then taper back down to 12 amps for 2.5 minutes. It probably averages out somewhere around 25 amps because the tapers between the different rates take about 40 seconds to complete. So, overall, I probably get about the same charge out of this unit than I did out of the old one (it measured 31 amps constant into a discharaged battery).

The 6000A is probably smarter and probably will handle most larger batteries better than the 2500A, but since I have a mixture of large and small batteries that I want to use with it, I don't have as much flexibility. I can't put anything smaller than about 65AH on it and set it for 10/30 because it will hit it with too much current. I wish, for example, that I could limit it to 10 amps (or less) when I use the 18AH batteries from the UPS units I just received (more on these later). For a 32AH battery, a rate of 8 amps or so would be ideal for me. While the 2 amp rate is probably better for the battery, it simply takes too long to charge.

Oh well, it will still work well for chaining up several together and doing them all at once if I need them quickly*. And it will certainly work great for when I'm running it off of my generator if my solar arrays aren't getting the sun they need (if I ever get some solar arrays :). I think I'll go hook it to the 1984 Blazer I've had sitting in the street for the last 6 months (because it needs work). I'm sure it could use a little electron boost by now.

*Be sure to wire up all of YOUR batteries with at least TWO Anderson connectors each so you can do this kind of thing whenever you need to.