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APC UPS using apcupsd

Date: Thursday 18 April 2013
Changed: Friday 24 May 2013

Finally got myself a nice APC UPS. A Back-UPS CS 500 to be precise. A UPS is a box containing a battery so that a desktop-PC in case of powerfailure can savely shutdown.

I bought it second-hand for €20,- , but when I received it it turned out the battery had to be replaced, which costs another €35,-. Then I needed the proprietary data-cable, which would have costed €35,- which is insane for a simple USB-cable.

This data-cable is needed so the computer knows when power is down and the battery is draining. When the power gets down it send an email, so when I am away from home I know there's something wrong. Another nice feature is that this way you can measure the powerconsumption and calculate the money it costs on energy. You can use the UPS without this cable, but it won't shut down automatically. If it's only for a PC you work on, this might be enough, but for a 24/7-server this is not very useful. If you have the data-cable you can use apcupsd for Linux to control it and read the values.

I decided to create a cable my own according to this pinout scheme. It turns out that it's just a simple USB-cable. I bought myself a second-hand, 75ct mouse for the usb-cable and then I needed the very uncommon connector to plug into the UPS. This turned out to be a 10p10c-connector, which looks very similar to a RJ-45 connector used for network-cables, but this connector has 10 connections instead of 8. I could get this connectors from electronic-webshop for 90ct a piece.

I did have a good RJ-45-tool for networkcables, and when used with these 10p10c-connectors it closes 8 out of 10 of the connections nicely. The two outer connections had to be closed using a plier and a small screwdriver.

This particular version has a capacity of 500VA and 300W: My PC/server consumes 30% of that which calculates to about 16 minutes of battery power. I plan to also connect one monitor and the modem to it, which makes this time of course shorter.