Recommendations for power supplies and battery backup ?

[TomjNorthIdaho]

Power question re each of the Netonix DC powered switches.

Question 1 ) What are decent 110-VAC to DC power supply products ( with a battery charger ) for each Netonix DC powered switch running 80 percent of the ports with 24-Volt APs averaging 4 to 7 Watts ?

Question 2 ) What is a suggested battery amp-hour rating for each Netonix DC powered switch to POE power 80 percent of the ports with 24-Volt APs averaging 4 to 7 Watts - and keep everything running for 3 days when the power is out ?

I am an ISP/WISP in North Idaho. I want to be able to last at least 3 days if/when the power goes out. ( Example , when the power goes out at some of my remote rural tower sites, the power has sometimes been out for 3 days to a week or more. )

FYI , at this time I am planning on retrofitting about a dozen of my remote tower sites with Netonix DC powered switches. Only 5 of my tower sites already have telco neg 48 battery systems. My remaining 7 tower sites have no battery systems. The latter 7 tower sites with no DC battery system is what I need to plan for - hence my two questions.

Additionally , I want to compile a suggested product parts list I can use when we add additional tower sites.

IMO , running 110 Volt 1500 watt UPS systems is crazy , unless you only need two hours or less of battery run time.


Thank you for any input and/or advice.

North Idaho Tom Jones

[Omniflux]

Hi TomjNorthIdaho,

I have sites in central and northern Utah.

You're asking a percentage of ports question, but did not specify which model of switch, and there is a pretty large difference between the WS-6 and the WS-26.

This post is helpful: viewtopic.php?f=6&t=258#p1006
The numbers may be slightly different for the WS3 models, and I think the AirMAX radios it mentions are model M which is probably not what you are using, but...

F = Number of fans
N = Number of ports
X = Average radio usage watts
H = Outage hours
V = Battery voltage
W = Watts you are planning on supporting
Y = Amp hours you need

(10 + F + N/2 + N*X) / 0.85 = W

H * W * V = Y

We don't like to drain our batteries below 50%, so H * W * V * 2 = Y.

However, batteries are less efficient in the cold, so you probably want to increase Y by a little...or a lot...depending on the batteries you are using.
See this thread viewtopic.php?f=6&t=1255#p9471


Nearly all our sites have a generator inlet they automatically switch to in the event of mains failure so we can quickly plug a portable generator in. Our solar sites that are difficult to get to in the winter we have permanently installed fairly cheap electronic start generators that we have converted to remote start.


I cannot recommend a good power supply with battery charger, I have not used any that I have had good success with that also fell within the budget I was given. I'm currently just floating everything with Meanwell SDR-480-24. Make sure whatever you get can charge both a fully drained battery and support your load at the same time, or you will have problems after power is restored. I tested the SDR-240-24 and it was insufficient for what I need. I've also tried some smart chargers that decide the battery is bad and shut off for safety even if the battery is fully charged when I also have a load connected to it.

I really like the Alpha Cordex PSU 24V/400W, but did not end up using it due to cost.

Prior to the current floating I'm doing, I deployed MinnKota dual bank chargers at a dozen sites. I now have a pile of MinnKota chargers with only one working bank charger each. When they fail this way, one battery stays fully charged, and the other slowly drains, and eventually the switch shuts down. Last I knew, these chargers have worked well for Sirhc, so I may have been doing something wrong...