I recently found out that my APC SU1000NET unit is faulty. The battery is brand new and I verified that.
It's a pain to pay over $125 for a company in Arizona to ship a replacement unit. That's 3 days for the echeck to clear and a couple more days for the unit to get here. Wouldn't it be great if I could go to the local auto parts and electronics store to solve the problem? Well, I've been studying the problem a bit. I know I need an inverter/charger and a rectifier. What I haven't found out is how many batteries and what kind to use. I see a Coleman 1000 watt inverter on ebay and it supposedly shuts down automatically when it's about to deplete the battery... but how do I signal the computer that the batteries are about to be drained completely? I don't know if the Coleman unit is a charger as well or just an inverter. A UPS needs surge suppression capability and undercurrent protection and most of the time power should be applied w/o using the batteries. The nicest way to do signaling would be to use say a PIC micro controller and put a signal out over the local ethernet line. So, what kind of batteries should I use? I don't like the typical sealed lead acid because where do you get them A and how do you revive them without special equipment B? Nickel metal hydride batteries are a possibility where the AA variety are available at most electronic stores. Nickel metal hydride RC car packs might be ideal. Another possibility is to see about getting say D cells. There are some AA Lithium ION batteries, but I don't think these are typically rechargeable batteries. There are laptop battery packs, but using these might be a bit of a challenge and expensive. So I am thinking car batteries as they pack a lot of punch, are available practically everywhere, and they are recoverable without special equipment. However, open lead acid batteries are not appropriate for use on a desktop. I've also heard if these batteries don't vibrate that they will sulfate up much faster. So say I start with 2 12V car batteries. A do it yourself UPS doesn't make much sense unless the UPS you are replacing is say an APC Matrix UPS, so let's pretend that we are doing just that. For the inverter, do I need a 1000 watt capacity? Do I need more than that? How do I figure out how many batteries to hook to it? For the rectifier/charger, do a typical say car battery charger if I'm using lead acid auto/marine batteries? Will the typical marine/auto battery battery charger stop charging when the battery is fully charged? How do I monitor the state of charge and report that on the network? Perhaps for the rectifier/charger and inverter I should build my own, but how do I do that? Well, here are the results of a quick google search: http://www.dansdata.com/diyups.htm http://www.wikihow.com/Build-Your-Own-Uninterruptible-Power-Supply http://www.diy-computer-repair.com/UPS-Uninterruptible-Powe-Supply.html http://dev.emcelettronica.com/ups-uninterruptible-power-supply-reference-design _______________________________________________ PLUG mailing list [email protected] http://lists.pdxlinux.org/mailman/listinfo/plug
