ePMP F180 Restart when connected to a DC source

I installed a cpe few days ago and noticed that whenever I tried using a MultiPurpose Powerbank/Mini-UPS, PoE 430P For Wifi Router, the radio restarts continously but this doesn’t happen when connect to AC using the in box POE injector.

Multipurpose powerbanks is set to 24v
Length of cable used is over 50 meters.

Please what might be the cause and a possible solution.

Thank you.

Hi. The Cambium SMs normally run on 30v from their supplied POE, at up to 15 watts. The SMs can work on lower voltages, but I would suspect your 24v supply maybe doesn’t have enough to quite do the job at that cable length?

In short, I’m guessing some combination of lower Voltage, and/or lower Amperage, and/or longer cabling is all conspiring against you. 🤷

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I have used the 24v multipurpose powerbank serval times and I have customers who use them too and have never complained about Radio going off and on or any issue while using it.

I suspect the length of cable and also the way the cable was run. It’s not a straight run but one where it has few bends.

As already pointed out, cable though not the only culprit!

We have whole towers running on 24v without issues. The f180 will run down to 11v just fine but they reboot if they do not get enough amperage no matter the voltage. We found cables that are not properly crimped can pass gigabit data but one of the power pairs has only one pin done well enough for dc power (the data signal can capacitively couple a poor crimp but dc wont). We have also seen a bad dc poe injector do the same so double and tripple check everything!

These radios are nominally 24v, but normalized 24v is 28.6v (what a common battery supplies) and normal battery equalization charge is 29.96v. So confusing as it is, this is normal 24v voltages. What matters is the available current to the radio which is reduced by the amount of wire between the power source and the radio and since parallel resistances together are less than the resistance of a single path you may just be over drawing what is available to the radio.