I've got an interesting situation at one of our high sites.

We appear to have had the solar panels stolen and the radios are shutting down. That's the short of it.

The longer version is as follows:

The high site is excellent. It's one of the best in the Western Cape and gives me clear line of site to everything I need to see. It's in a conservancy area. There's obviously no electricity, and I couldn't put up a wind turbine because the ramblers staying overnight in the hut nearby don't want to hear "woosh woosh" all night long.

I had 6 x 55W solar panels charging 4 x 102Ah deep cycle batteries. We had a big storm last week. The solar panels either blew away (I find that had to believe as they were secured onto steel frames that were concreted into the mountain) or they've been stolen. Either way there's no power coming from them. The site itself doesn't have any paying clients connecting to it, but the 3 RB600's all have XR5's with large aerials on them. It's a repeater site in the true sense of the word. It connects access points with our two NOCs and provides for redundant links.

Yesterday I started getting "voltage low" emails. I drove out there, but the track is too wet for me to go up. It may dry out enough for me to try on Tuesday or Wednesday.

We have a Land Rover Defender with a big V8, big mud tyres and diff lockers in the front and back axles that we need to drive for more than an hour in low ratio to get from where the tar ends to where the tower is - that's when the track is dry. It's much worse when the track is wet.

As things stand now, the batteries are down to 11.7V and it appears that some of the radios are no longer working.

wlan1 on each rig still works. wlan3 is dead. wlan2 works on one rig, but not on the other two.

Am I right in thinking that things will return to normal once I've got the batteries charged up?

Update.

While I was typing this, voltage dropped to 11.6V and I can no longer get into any of the radios using winbox.

You should do ok until the voltage gets below 10 volts. From personal experience, when the voltage drops below 9 volts, the unit will lose its mind, and then its license. No thing. Your dealer can help you with the license reinstall if that happens.

ADD: Are you certain the solar panels are gone? I had a solar charger fail before, and the results are about what you are getting. And you might want to check the huts that don't like "whoosh whoosh" to see if they have your panels!

You will figure it out when you get to the site. I have been through some really bad storms (hurricane Opal as an example), but none have been strong enough to remove bolts or screws.

My solar chargers now have Low Voltage Disconnects (LVD). They disconnect the load at about 11 volts. They reconnect it at 12.5 volts.

Sounds a lot like one of my sites in Panama.
See my thread on a similar subject: http://forum.mikrotik.com/viewtopic.php?f=7&t=31927

Turning off a wind turbine overnight is very simple. If you have wind then wind energy is much cheaper than solar power.

How do you monitor the battery voltage and where?
Do you measure the voltage at the batteries or at the radios?

My experience is that RB411A routerboards + high power radios will go dark at somewhere around 8.5V to 9.5V, as SurferTim says.
The voltage was measured by a nearby RB450G.

At 11.6V, your radios should run perfectly fine.
If you are measuring the voltage at the batteries, then you are losing too much voltage to the wires - do something about it.
If that is the case, you are probably wasting over 30% of battery capacity on wire loses.
400 Ah should easily keep you online for 3 days. I can run 3 XR5s in 3 RB411A for 70 hours on 160 Ah from 100% to 0% charge.

Anyway, you should be just fine when you get the batteries charged.

We have a site where a solar panel is supplemented by a windmill but after a solid week of cut-outs and reboots every few minutes and "jan/01/2002 14:00:02 system,error,critical router rebooted without proper shutdown, probably power outage" reports in the syslog we turned the windmill off, since when all has been fine.

We're still investigating the problem but current speculation is that the windmill, which locks the generator up to prevent the rotor turning when the batteries are fully charged, was spinning up with charged batteries in gusty weather and the 'lock-up' function was causing either a voltage drop or 'shock' through the system which either caused the regulator to cut off the power to the board (an RB532), or was actually causing the board to momentarily shutdown.

So if you're thinking of getting a windmill be sure you understand how it's going to affect the system.

If anyone else has experienced this problem we'd be interested to learn to solution.

What make of Windmill was this?

I've only ever used the ones from Southwest Windpower and have never experienced this.

What make of Windmill was this?

The Air Breeze 200w turbine.

We're still trying to find out what was happening.

We have a site where a solar panel is supplemented by a windmill but after a solid week of cut-outs and reboots every few minutes and "jan/01/2002 14:00:02 system,error,critical router rebooted without proper shutdown, probably power outage" reports in the syslog we turned the windmill off, since when all has been fine.

We're still investigating the problem but current speculation is that the windmill, which locks the generator up to prevent the rotor turning when the batteries are fully charged, was spinning up with charged batteries in gusty weather and the 'lock-up' function was causing either a voltage drop or 'shock' through the system which either caused the regulator to cut off the power to the board (an RB532), or was actually causing the board to momentarily shutdown.

So if you're thinking of getting a windmill be sure you understand how it's going to affect the system.

If anyone else has experienced this problem we'd be interested to learn to solution.

I had pretty much the exact same problem with the Air X. But mine was worse - about 30% of the time the board would reboot, and the other 70% it would freeze.
Freezing is of course far worse, because it would be down until a manual reboot, not just 30 seconds.

I ended up getting a 12V UPS from http://www.powerstream.com/12V-backup.htm and attaching it to a small 4 Ah backup battery.
That got me from a crash every 1-2 days to a crash about once a week.
I then added a 4700uF capacitor in parallel with the load. Since then, 1.5 months of 100% uptime.

What make of Windmill was this?

The Air Breeze 200w turbine.

We're still trying to find out what was happening.

OMG That's the same ones we use. Touch wood we've never had any issues.

OMG That's the same ones we use. Touch wood we've never had any issues.

The problem may not be with the windmill per se. It's connected directly to the batteries as it has its own controller but the solar panel is connected to the batteries through a solar controller and the wireless gear takes its 12v feed from the solar controller. The problem may be with the way the solar controller reacts to the battery voltage as it is affected by the windmill - it was very noticeable that the problem was worse at night. We're still trying to nut it out, but the site is not very accessible which makes investigation difficult. We don't want to go up there until we've at least some idea what's going on and what the solution might be.

and what the solution might be.

Did you skip over my post?

Did you skip over my post?

No, but until we know WHY what is happening is happening we won't know how to stop it happening.

Your approach is a patch and it may be in the end the only solution for us but eben uses the same turbine without suffering the same issues which suggests the problem lies elsewhere in our system, and we'd rather fix the problem than patch over it.

The problem may not be with the windmill per se. It's connected directly to the batteries as it has its own controller but the solar panel is connected to the batteries through a solar controller and the wireless gear takes its 12v feed from the solar controller.

What controller are you using?

My windmills are connected in the same way (ie direct to the battery banks), but I use Steca Solstum controllers as they are supposed to be the best.

My equipment is connected to the "out" on each controller. What happens when you connect the kit direct to the battery and only use the controller as a voltage regulator for the solar panel?

I got the same configuration of eben, with 3 windmill in the same site ( we are in a windy and sunny place, so we are plenty of power.)
No voltage issues nor disconnections.
The windmill is Air X too, and it should have his own charge controller (IIRC)

Windmills
\/
Batteries ---> Equipment
/\
Solar Panels with charge controller

What controller are you using?

We're using the Steca Solstrum too, and with the same configuration as you and Medianet but we're getting problems and you're not. Odd.

My vote would be to power the wireless gear direct from the batteries but I'm outvoted on the grounds that if both windmill and panel "disappeared" (to adorn someone else's country estate!) we wouldn't know until the equipment had drained the batteries, and as they are gell-cell 6v ones that could be damaging.

If the board cuts itself off if voltage drops below 11 this wouldn't be so much of a problem, but I think that with the input via the jack-plug the RB532 can go right down to 6v and still work.

Now that the weather's settled down (we were getting gusts of 140kph last week) we're going to reconnect everything tomorrow to see what happens.

My vote would be to power the wireless gear direct from the batteries but I'm outvoted on the grounds that if both windmill and panel "disappeared" (to adorn someone else's country estate!) we wouldn't know until the equipment had drained the batteries, and as they are gell-cell 6v ones that could be damaging.

If the board cuts itself off if voltage drops below 11 this wouldn't be so much of a problem, but I think that with the input via the jack-plug the RB532 can go right down to 6v and still work.

Why don't you connect directly to the batteries and monitor the voltage with a EB433AH or RB450G?
If the voltage goes too low for your batteries, you can shut down the system remotely.

For us, losing a little battery life (by discharging it too much) costs much less than offline customers.

Hrmm, do you guys run a Solar controller that supports diversion ? For example the Morningstar TriStar 45 and 60 do, but the SunSaver range and most Steca's do not.

You need to run a diversion load, e.g. a 12/24volt heater

If not, this is probably your problem.

My system runs all 12V based FYI.

According to the docs, a diversion-type charger would only be needed with an alternate charging source that does not have its own regulation. My supplier assures me the Air Breeze wind generator and any of the solar chargers they offer will work together. The Air Breeze has internal regulation.

My supplier assures me the Air Breeze wind generator and any of the solar chargers they offer will work together. The Air Breeze has internal regulation.

+1

Those little things have clever regulators. I have some that have very short cables and I have some that have LOOONG cables and no matter how long the cable, the correct voltage always gets to the battery.

One thing about the Southwest Windpower turbines...

It's important that you buy the "land" version and NOT the "marine" version. We've had several snake oil salesmen try to sell us the "marine" version. The units look the same as the "land" version, but the circuitry is different. The bottom line is that they do not work properly to keep high sites powered up.

Hi eben,

The only difference between the land and marine versions is supposed to be the exposed metal parts are stainless steel on the marine version. I will look into that. Very interesting.

The reason that wind charger is so clever is the way it determines battery charge state. It waits for a PWM "off" cycle to read the battery voltage with a hi-z input. That way any line resistance from the wind generator to the battery will not affect the reading.

The batteries I am to assume are connected in series and you are measuring 11.6 V at the battery. If this is the case then they are most likely discharged, the RB600s would put very little load on them and I would imagine when properly working they would measure 12.6 - 13.2 volts. Its not the voltage thats killing the radios its the current, the RB600 can operate down to ~10 V without having too many problems but they would require more current. In a interesting coincidence about 6 months ago I experimented with a pair of RB600s each with 2 x XR5 (each) and put them under a working load with a 48W power source. I monitored the power usage and found that it was peaking around 22W, with the link not sending any data it was around 16W. I swapped the power supply out for a 18W one (a common 48V 0.4A one) and did the same test, the links with no data transmission did not drop, but as soon as I transmitted data with both at the same time the links started to drop.

As a side note I've had 4 x 120 Ah deep-cycle batteries that after only 6 months stopped holding a charge.

If it was me I would suspect the batteries 1st, and charging controller 2nd

Cheers

I monitored the power usage and found that it was peaking around 22W, with the link not sending any data it was around 16W.

Anyone knows if these numbers are lower when the CPU frequency is reduced?

Hi Guys,

We have many Mikrotik routers out in the field running from solar or DC based supplies.
A lot of mains powered sites run from 12v SLA batteries, charged off the mains, giving us many days of power, compared to using a conventional UPS lasting upto an hour. Rather than providing 120 / 240v power, and stepping down to 12vdc to power the board.

Were trialing a new power monitoring system we have developed to work with RouterOS's UPS package.

The piece of hardware connects to the RouterBoards serial port, or USB connector and allows you to monitor the voltage of the DC supply and state of power connection (mains fail etc). The new "In development" version also allows you to monitor site temperature from the UPS tool too. All this information can be then used to generate Mikrotik scripts, to report power loss, battery voltage, temperature alarms etc.

We're hoping to make a few more units at low cost for a few interested customers, PM me if your interested.

Cheers,

logix

Were trailing a new power monitoring system we have developed to work with RouterOS's UPS package.

The piece of hardware connects to the RouterBoards serial port, or USB connector and allows you to monitor the voltage of the DC supply and state of power connection (mains fail etc). The new "In development" version also allows you to monitor site temperature from the UPS tool too.

Remember that some routerboards, like RB433AH and RB450G, already have built in voltage monitoring. The RB450G also has temperature monitoring.

Thats true RK,
But how do you detect loss of mains power easily from the routerboard?

The idea of the unit is primarily to make use of existing infrastructure running on older hardware, and for potentially less than $100, the interface is quite an affordable add-on as a long runtime UPS for remote comms sites.

A customer of ours has lamp post mounted wireless hardware, and all the gear runs from a 12V battery, trickle charged from the mains supply. If a service fuse blows, they want to know immediately the loss of mains, before the battery discharges.

logix

Remember that some routerboards, like RB433AH and RB450G, already have built in voltage and temperature monitoring.

The RB433AH has temperature monitoring?

Thats true RK,
But how do you detect loss of mains power easily from the routerboard?

The idea of the unit is primarily to make use of existing infrastructure running on older hardware, and for potentially less than $100, the interface is quite an affordable add-on as a long runtime UPS for remote comms sites.

You could monitor the input voltage, and if it drops by more than 3%, you know your battery is discharging and your mains are down.

The usefulness of your product depends on cost. At the right price, I'm certain you can sell hundreds.

Remember that some routerboards, like RB433AH and RB450G, already have built in voltage and temperature monitoring.

The RB433AH has temperature monitoring?

No. That was an error. Thanks for pointing it out.

We use 270w of solar panels, 460 amp/hr of gel cells, a Specialty Concepts Mark 22 controller and the LVD circuit on a Specialty Concepts ASC 12/8 for low voltage disconnect/reconnect on 3 remote sites. Load is 2-532a, one with a daughterboard and 3 cards, one with a single XR5. Northern New England. Severe winters. Very few problems considering the climate. But when something fails, it's always mid-winter and real fun to fix. Hence the addition of of the LVD on all sites. You don't want to be replacing a battery bank on a remote mountain in the middle of winter. The radios will take the battery bank down to such a discharged state(1 1/2 weeks no sun) that the panels can't recover them. Or the charge controller will cease to function. Or both.

Regarding your specific problem (if the panels haven't been stolen), I'd suspect bad connections on the panel>controller>battery wiring, or maybe a blown fuse in the charge controller(if it has one). We use the Specialty Concepts controllers because they are slow switching and don't produce RF interference. That turned out to be a real problem early on when we were using PWM fast switching controllers. Your radios will run fine all the way down to around 9v-but at that point the battery bank may not be able to recover.

Good Luck, GB

I never did report back on what we found when we got up there.

The panels were gone.

We used cap screws and Nylok nuts. The thieves took allen keys and undid them.

The new ones have been put in place with "security bolts" and sheer nuts. Next time they'll have to use a hack saw to cut the framework down.

There's obviously no electricity, and I couldn't put up a wind turbine because the ramblers staying overnight in the hut nearby don't want to hear "woosh woosh" all night long.

Good thing for those ramblers next door it is your site! They would be hearing more than "whoosh whoosh" all night long. I would install a "boom box" on site and play gangster rap at 95db all night long!

ADD: This kind of problem is not uncommon. My insurance agent told me the companies he represents won't insure solar panels here (the beach) at anywhere near a reasonable price. "Better to put the money in the bank to replace it right away." He said they are either stolen, or destroyed in the attempt. Mine is on a roof behind secured doors with security guards on the property.

eben

you should use this mate,
http://www.remotemonitoringsystems.ca/rms2/

it works just perfekt, and you can attach sensors as intrusion detection. It can tell you a lot about your bateries and have remote on/off access. this board does everithing for you and in a long run is cost effective if you set it up properly.

depending on setup (cards, boards), maybe CPEs connected/wlan interface i found that 1V makes a big difference.

do you power your boards directly from bateries?, if not i think you should. It will work just fine.

Steven

Forgot to add - fit a IP camera, they have motion detection and can be conf to sand you nice emails with smily thievs

Thanks, semakka. You have given me an idea.

Mikrotik crew: Do you know which RS232 pins the UPS package monitors? That would save me going through APC's docs to find what they use. I could see where that input could be adapted to an alarm sensor. I already know the LEDs on a RB433AH will activate a photo-transistor for a couple of isolated outputs if I need them.

EDIT: Never mind. The service I really need is no longer available (/tool sigwatch).

you can use a RB433UAH or an ALIX board with usb ports to monitor Back and Smart UPSs - it worked for me in the office. here depends on how big is the distance between board and the UPS, being USB.

we use smart APC UPSs with management cards. you can SNMP and graph them, web them, telnet, ssh them, do whatever you want.
they send allerts too.

a 700VA APC Smart UPS with management card will cost you about 700€ but is worthed

Cheers,