28/11/2008

The law of gravity

Whether you're tramping up a hill, or kicking a ball, or whatever, one of the first things you learn is that things come down much more easily than they go up. That's gravity for you!

I've come to appreciate exactly the same phenomenon for rechargeable batteries. Today, I've been setting up a brand new UPS to power three laptops and a printer; I've read from HP support that it's best not to leave a laptop battery in the laptop if you're running your laptop for long periods of time, so, in order to do that and still have some protection against power outages, I felt that a UPS is the best option (not to mention that it helps protect against power surges, which have killed more of my computers than I want to think about).

Anyway, as a test of the UPS-monitoring interface (if you're an Ubuntu user, the nut-hal-driver package is all you need, if your UPS has a USB connector like mine does), I decided to unplug the mains for a while, and see how long things would run. The system estimated about 20 minutes of run time. When the UPS got to about 70% charge (after about 5 minutes), I plugged it back in. As of current writing, it's been charging for forty minutes now, and it estimates taking another twenty minutes to finish charging.

Yeah, you definitely don't want to be having power outages too often, UPS or no. :-)

Update: it's now been charging 75 minutes now, and still estimates 20 minutes to finish charging. This is starting to look like software development schedule estimates! :-P

No comments: