Re: Battery power for Node 4629


At 06:01 AM 2/21/2009, you wrote:

If you are planning to run on 12v for primary power, the object should
be to first minimize the consumption of all components. A 12v node
computer *can* consume as little as 10-15 watts. If you need a router,
find one that runs from 12v directly (my Cradlepoint runs from 12v, as
do many Linksys), probably 4-5 watts. Of course you need a repeater
running from 12v also. My mobile Kenwood repeater consumes about 6-7
amps (95 watts) on transmit at 25 watts. On receive (idle) around 700
My setup is evolving along similar lines. I have a 40 amp switchmode power supply for my primary AC. This is connected to a 50Ah SLA battery via a solid state changeover switch. The output of the power supply has been tweaked up slightly to allow for the voltage drop of the Shottky diode in the changeover switch. The switch also provides charging current for the battery from the power supply.

The cable modem and router are powered by a 240V inverter. I could probably power the cable modem directly off 13.8V, but itg was provided by the cable company, and I don't want to go screwing around inside, in case something breaks and then I have to get it fixed. Too many questions asked. Unfortunately, the router runs off 5V, but it at least uses a switchmode power supply.The repeater itself runs directly off 13.8V, and has similar power consumption to yours (it's a 25W system also).

The node PC currently has no battery backup, but I am going to buy a couple of replacement SLAs for one of the 700VA inverters I have. With only the node PC running off it, it should manage at least 90 minutes run time. Down the track, I wouldn't mind some sort of generator backup.

a mini ITX PC would be nice, but that's another thing on that long wish list. ;)

73 de VK3JED / VK3IRL

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