Hi Guys

Looking for a little advise around powering MikroTik radio's with batteries in a total loss scenario, specifically a LHG and a mANT19s box...the reason for the total loss scenario is that it a solar panel generation option is prohibitively expensive at this time, so my questions are :-

1/ These devices in theory could run off a single 12v battery?
2/ How can I calculate the duration of battery life
3/ How could I measure the performance of the battery not to have degradation on the radio links?
4/ Are there any devices to run PoE from multiple batteries in sequence?

If I am being wholly silly and stupid here, please do tell me

Mark

Hi Guys

Looking for a little advise around powering MikroTik radio's with batteries in a total loss scenario, specifically a LHG and a mANT19s box...the reason for the total loss scenario is that it a solar panel generation option is prohibitively expensive at this time, so my questions are :-

1/ These devices in theory could run off a single 12v battery?
2/ How can I calculate the duration of battery life
3/ How could I measure the performance of the battery not to have degradation on the radio links?
4/ Are there any devices to run PoE from multiple batteries in sequence?

If I am being wholly silly and stupid here, please do tell me

Mark

You should be able to run almost any Mikrotik product using battery power.

In you environment , there are a couple of ways.
One might be use an Ethernet POE injector such as the Mikrotik RBPOE. It has three connectors - Ethernet in & 12-48 volt DC jack & Ethernet out to the Mikroitk.
Just connect up a 12 volt to 24 volt battery to the POE.
To get 24 volts use two 12 volt batteries in series and use two 12-volt chargers in series.
Don't forget fuses

Now if you are into some electronics - then you could build yourself a powersupply TAP which connects to your AC/DC power supply to your Mikrotik. The TAP part would be a parallel connection to your battery. You will need two diodes and a 10 to 25 ohm resistor which slowly charges the battery over time. The second diode facing the other direction is you battery out. Them when AC power goes out, the battery will carry the load. When the AC power returns, the AC power supply will power the mikrotik and slowly charge the battery.


Re: How can I calculate the duration of battery life
A general estimate is battery amp-hours divided Mikrotik amps (look up the specs of your Mikrotik) - then plan on about 1/2 of that time.
Thus a 12 volt battery with a 10 amp-hour rating connected to a .3 (point 3 amp) load, should be able to power your .3 amp load at 12 volts for about ( 10 / .3 ) = 33 hours --- now half of 33 hours is about 15 hours at 12 volts.
These are only guestimates - you may need to build and measure.

Re: How could I measure the performance of the battery not to have degradation on the radio links?
Connect up a charged battery, power up the Mikrotik and use it. Use a volt meter on the battery. When the battery voltage drops below the Mikrotik specified voltage (look at the specs), then that is how long you have. It would be best to subtract about 25 to 33 percent of the time you tested - to allow for battery aging where the battery is no longer as good as it was when it was new.

Re: Are there any devices to run PoE from multiple batteries in sequence
yes - many

North Idaho Tom Jones

The most easy is to use ad155b power supply from meanwell or some of the clones and add 2x12v batteries. Connect it to the poe injector and you are done. Use traction batteries. For battery related questions visit other forum that specialise in that.

jarda
re: Use traction batteries

I have traction tires on my Toyota FJ - will that do ?

lol everybody

Tom, what do you find funny on traction battery?

and what is the traction battery?

I think a traction battery is another word for a heavy-duty and/or deep-cycle battery (which use a slightly different plate construction inside the battery).

Hi,

Why no Solar?
Here in Germany we Can easy Bye Used Solar Panels.....

An SXT or Dynadish consume about 3-4 W,
LHG and Mant19s coud be used direct on 12v.

2 x 4W at 12V = 0,67A
For a Day you Need 24 x 0,67A = 16,1 AH
If you Choose a leed Acid / Gel / AGM Batterie you Can only discharge 50% of The capaticity of The Battery.

If you choose a 150 AH Battery /2 = 75 AH useable
75 / 16,1 AH = 4,65 days
So These Setup will run 4,5 days them you have to recharge The Battery.

LiPo or LiFePo Batterys Could be descharged to 100%, but These Battery Are realy expensiv!

If you Need more then 2 devices connected take a Look to netonix DC Switch



Mistry7

To find out how long a network device runs on battery, I connect it to a manged switch with a syslog server.
Then I can see int the sylog server when the unit dies, since port goes down.

Why no Solar?

There are many WISPs that use solar panels for power.
However, I have little experience with solar power. Mostly because I know solar panels in my area have zero power when they are covered with 3+ feet of snow/ice on them during our winder months.

There are plenty of ready-made solar power kits available.

Hi Tom,

And your Solution is carying Batterys?
There Are 4 Ways for a WiSp Station without Power avaible

1. Exchange Batterys even they Are discharged

You have to Go there every 8-10 days, and Exchange The Betterys, and with a Cycles over 50,% The Batterys Will Not get old.

2. Using Solar for Recharge

Needs for Panels depends on your Region, but Snow is removed easylier then Carry new loaded
Battery to The top of a Mountain.

3. Using Wind for Recharge

In Hard Winters Combination of Solar and Wind do it

4. Using Fuel Cell for Recharge

Expensiv, but working for all places.

Mistry7

Hi Tom,

And your Solution is carying Batterys?
There Are 4 Ways for a WiSp Station without Power avaible

1. Exchange Batterys even they Are discharged

You have to Go there every 8-10 days, and Exchange The Betterys, and with a Cycles over 50,% The Batterys Will Not get old.

2. Using Solar for Recharge

Needs for Panels depends on your Region, but Snow is removed easylier then Carry new loaded
Battery to The top of a Mountain.

3. Using Wind for Recharge

In Hard Winters Combination of Solar and Wind do it

4. Using Fuel Cell for Recharge

Expensiv, but working for all places.

Mistry7

I am not against alternative power. However ...
I prefer to have buried utility power (and buried fiber optic cable) and a 1,000 gallon tank for a propane generator, then about 45 minutes of battery run time.
I need the high-amperage ability because some of my remote towers on mountain tops are loaded with all kinds of communications equipment (WISP, phone, multi-government networks and 2-way radio repeaters). We also need electric heaters to keep the equipment warm enough to run - especially when the snow can be as deep as the tower building is tall (note - one building has a door in the roof) and it is -35 degrees outside (not counting the wind chill factor when the wind is howling at 65 mph. And in addition to everything, there is more than 4 inches of radial ice covering everything and the tower is fully packed with snow where you can not even see where the antennas are mounted on the towers.

For locations where there is reliable access 24/7, mild weather and low current loads, then I fully agree that alternative power is a very viable solution.

One of the problems with portable car chargers / AC inverters is they are designed for temporary use. They are not designed or intended for 100 percent non-stop usage 365 days a year year-after-year. Most of the small low-cost chargers / AC inverters use low-cost low-quality parts to keep the consumer purchase price low and competitive.

I think you will find that these low-cost items will have capacitor failures and cooling fan bearing/bushing failures and transformer insulation break-downs and will not deliver a true sine wave and the 50/60 hertz frequency will wildly drift when they are cold or hot.

Yes - they do work OK for temporary use - but in extreme conditions (temperature, load, EMF, RMF, input voltage, surge load, extended run-time), they all pretty much die just when you begin to think it is going to work OK.

Just my opinion
North Idaho Tom Jones

I am not against alternative power. However ...
I prefer to have buried utility power (and buried fiber optic cable) and a 1,000 gallon tank for a propane generator, then about 45 minutes of battery run time.

I would not know anything about large runtime . However we prefer long life on battery so the site stays up if the generator fails to start.



That is 3600 Amp Hours at 48 Volts. Powering a whole bunch of stuff for a regional two way trunked radio system. That is in addition to a large generator and twist lock connectors that allow us to quickly hook up a portable generator in the event that the main generator fails.
Sorry for getting off-topic a bit.

I am not against alternative power. However ...
I prefer to have buried utility power (and buried fiber optic cable) and a 1,000 gallon tank for a propane generator, then about 45 minutes of battery run time.

I would not know anything about large runtime . However we prefer long life on battery so the site stays up if the generator fails to start.



That is 3600 Amp Hours at 48 Volts. Powering a whole bunch of stuff for a regional two way trunked radio system. That is in addition to a large generator and twist lock connectors that allow us to quickly hook up a portable generator in the event that the main generator fails.
Sorry for getting off-topic a bit.

I am guessing that at a sustained 30 amp draw, you are good for almost a week - nice. That will set you back a few bucks to replace all those batteries at the same time. I know, about a year ago we just replaced about that many batteries on one of our large 3-Phase 200-amps-per-phase UPS systems at our primary server NOC.

Aside from my NOC locations, I also co-locate some equipment in an Internet meet-me co-locate building in another state. They don't really have UPS systems - Instead they have huge monster fly-wheel UPS/temp-generator systems that will draw kinetic energy from the fly-wheels until all of the diesel generators start and come on-line. I am pretty sure the building is pulling a sustained 1,000 amps utility power or much more.

Speaking of batteries ...
Back in 1974 , I got to see the battery rooms an a hydro power plant. It was huge and very impressive.
When the dam goes dark and there is no utility power, everything uses the AC SPS/UPS inverter systems to bring everything on-line and back onto the grid. Dozens of electric motors drawing over 600 amps each.