I have a few queries related to power backup on my MIKROTIK devices:

I have attached a picture and can you suggest if we can directly connect the Battery leads + &- to the Mikrotik POE. The batteries are serially connected making it 24 Volts as per the power adapter of Mikrotik. However I have a separate charger for the batteries.

1. How much backup should I expect as per the diagram??
2. My charger which is charging the batteries is giving 2 amp to charge. Will it blow up the batteries??
3. Does it affect the Mikrotik since the AC adapters we use is normally 1 or 2 amperes.

Suggestion with illustrations are welcome. Thanks in advance...

Based off the max power draw on the 433AH datasheet you're looking at about 3.5 hours max though if you want to get the most use out of those batteries you'll get about an hour, maybe 1.5 hours.

That's no guarantee. When I'm designing a battery system I'll take my desired run time to get the capacity I need and then double or triple it. Deep cycle batteries are more tolerant of deep discharges but they'll last a whole lot longer if you minimize the amount they are discharged.

My more concern is ...is it safe to connect the Routerboard directly to battery leads. Someone from Mikrotik suggest...I can then work towards increasing the 7ah to 12 or 16 or 35AH as i may be in need for at different sites depending on the kind of power availability.

Certainly a concern is the direct charging of these batteries from a transformer giving out 24Volts and 2 amperes charging. May be this can be increased to 4 amps..what will be the implications.

Power is a major concern and not all of us find solutions with ease....

We are wireless internetprovider in Germany with 100 AP´s and arround 1000 clients.
For us "Restless Powerbox" as a power supply and backup is working flawlessly.

Mostly Compact type with 4 ports on relay Accesspoints. On big towers 8 port type with GSM modem to get remote access.
You will get full electrical control on all Routers by lan.

Claus

Hello Mahnet,

we are wireless internetprovider in Germany with 100 AP´s and arround 1000 clients.
For us "Restless Powerbox" as a power supply and backup is working flawlessly.

Mostly Compact type with 4 ports on relay Accesspoints. On big towers 8 port type with GSM modem to get remote access.
You will get full electrical control on all Routers by lan.

Claus
RSB / Germany

Hello mahnet,

you can use the Restless Powerbox as power supply with full control off your devices.
it is even a UPS with it integrated batteries.

Hello mahnet,

you can use the Restless Powerbox as power supply with full control off your devices.
it is even a UPS with it integrated batteries.

>What about availability in India?
>Please give a quote for different products and pricing.

Solder in an LM7824 on the (+) line between the battery and the POE Injector.
http://www.fairchildsemi.com/pf/LM/LM7824.html

That will filter the power down to no higher than 24V and deal with the over power problem if the charger pushes the voltage up past 28V.

Here's something that I recently did for a big site.

First of all, I decided to use 12V rather than 24V. The only reason why I decided to do this was because I wanted to keep all the variables on ground level. It's not fun having to replace one of those LM7824s when you are dangling 28m up a lattice mast.

If MikroTik could handle 10 - 30V, I would much rather have gone for 24V. You need thinner cables to run 24V than you do for 12V.

Here is the final product showing the DB rail with the switchgear and the 3 x 102Ah batteries in parallel to give me a 300Ah 12V battery. That should keep 1 x RB250GS, 1 x RB750, 1 x RB433AH, 4 x UBNT rockets and the camera going for a couple of days.
Power distribution is as follows:

From left to right:

Main circuit breaker with power cable that goes over to the cabinet's power distribution system.
Circuit breaker for the Meanwell blue and white power supply.
Circuit breaker for the timer / Meanwell chrome power supply.
Timer Switch. I use this to cut the power to the chrome PSU for five minutes each day. This "excercises" the batteries. Or at least that's what the clever people say.
Meanwell 12V Power supply that provides power to the...
Atcom ATA. This doesn't get clean power, so if the power goes off, it goes off. Dude then sends emails and Text messages to inform us of the power failure.
Meanwel 155W security power supply. I like these units a lot.
12V main circuit breaker
4 x 12V load circuit breakers
RB250GS
RB750

There's no theorising or beating about the bush here. This is currently working in a production environment.

The next high site will have one small change. I plan on adding a device called a GSM Commander and running power through relays to the load circuit breakers so that I can switch them on and off remotely using SMS text messages.

i would sure love to make something like that. But is it good and safe to connect 12 Volts for Mikrotik 433AH with 2 R52H Cards. Cable distance is like 75 mtrs DLINK Cat5 STP. Also the batteries are 7 AH and the amp. mentioned on the Power adapter for Mikrotik is 1.5 amp. Does that make any difference.
The LM7824s will be used only with 24 Volts.??

The problem i face is that sometimes the power does not go off for 10 days and the mini 7 ah batteries blow FAT.
I want a mechanism to cut down the charging supply when the batteries are full charged. I can increase the batteries to 16 amp or 35amp

Hi mahnet,
please contact me out of board for further question and availability about Restless Powerbox.

ks(at)cn24.net

i would sure love to make something like that. But is it good and safe to connect 12 Volts for Mikrotik 433AH with 2 R52H Cards. Cable distance is like 75 mtrs DLINK Cat5 STP.

It should be, as long as there's enough current.

Also the batteries are 7 AH and the amp. mentioned on the Power adapter for Mikrotik is 1.5 amp. Does that make any difference.
The LM7824s will be used only with 24 Volts.??
The problem i face is that sometimes the power does not go off for 10 days and the mini 7 ah batteries blow FAT.
I want a mechanism to cut down the charging supply when the batteries are full charged. I can increase the batteries to 16 amp or 35amp

Are you trying to use a 1.5A power supply to charge batteries?

If that is the case, then NO NO NO. DO NOT DO THAT.

Get a proper charger or one of the Meanwell security power supplies.

C-TEK make clever chargers that condition batteries.
http://www.ctek.com/

Here are links to the Meanwell chargers and security power supplies.

http://www.meanwell.com/webnet/search/seriessearch.html

http://www.meanwell.com/search/ad-155/default.htm
http://www.meanwell.com/search/pb-360/default.htm

[quote="eben"]Here's something that I recently did for a big site.

First of all, I decided to use 12V rather than 24V. The only reason why I decided to do this was because I wanted to keep all the variables on ground level. It's not fun having to replace one of those LM7824s when you are dangling 28m up a lattice mast.

quote]

Why would u have the LM7824s up the mast??? Do you have the POE placed on top of ur mast closer to the Routerboard. I don't like that. I have all POE's inside my room.

300ah is lot of battery i guess the number of gadgets u have mentioned should be going on for weeks than days only on so much battery backup.

Considering the fact that each Mikrotik 433AH with 2 X R52H cards takes 30Watts power I should power up almost 5 nos. of Mikrotik Routerboards with the AD155.

I would also say GOODBYE to all power adapters considering I paid 25$ approx for an original Mikrotik 24v adapter and 6$ for any other 24v Power adapter

I don't send PoE up masts.

I send a red and a black wire up, then have any PoE injectors as close to the equipment as possible. We use a type of cable called surfix (6mm 2 core) as the armour helps with reducing the magnetic field and the 6mm means little voltage drop.
http://voltmax-cables.co.za/core_surfix_cable.htm

We've found that when you are sharing a tower with VHF and UHF equipment, the PoE on STP (even the good UBNT Toughcable) causes interference - especially to the UHF stuff.

Hi eben,

At what price did u get the AD155a/b and PB360.
Is one AD155a/b good enough to charge 300Amp batteries like u r using.
What is actually the difference in between the AD155a/b and PB360?

You have a lot of circuit breakers and other things connected in ur picture can u be a bit more illustrative and guide us on that.
Thanks a lot

Hi eben,
At what price did u get the AD155a/b and PB360.

The AD155 is about half the price of the PB360.
PB360 is about US$100. This will obviously differ from one territory to another.

Is one AD155a/b good enough to charge 300Amp batteries like u r using.

So far so good.

What is actually the difference in between the AD155a/b and PB360?

The AD is like a 12V UPS, whereas the PB is a proper charger.

You have a lot of circuit breakers and other things connected in ur picture can u be a bit more illustrative and guide us on that.
Thanks a lot

From left to right:

Main circuit breaker with power cable that goes over to the cabinet's power distribution system.
Circuit breaker for the Meanwell blue and white power supply.
Circuit breaker for the timer / Meanwell chrome power supply.
Timer Switch. I use this to cut the power to the chrome PSU for five minutes each day. This "excercises" the batteries. Or at least that's what the clever people say.
Meanwell 12V Power supply that provides power to the...
Atcom ATA. This doesn't get clean power, so if the power goes off, it goes off. Dude then sends emails and Text messages to inform us of the power failure.
Meanwel 155W security power supply. I like these units a lot.
12V main circuit breaker
4 x 12V load circuit breakers
RB250GS
RB750

My more concern is ...is it safe to connect the Routerboard directly to battery leads.

Just make sure whatever you end up choosing, you have some sort of fuse/circuit breaker in-line near the batteries. Most Gel/AGM batteries can push out 20-30A or more when shorted, which can lead to exploding batteries and potentially a fire.

Also, check that your charger is designed for the type of battery you are using. Wet Lead-acid, Gel-cell, and AGM batteries all require slightly different charging methods, and few chargers handle all three types properly. I would probably go with one of the better changers mentioned in this thread that is designed for extended use.

What about the high voltage protection. I can see that PB360 -24 has cut off at 31~35 Volts which still means it excceeds the rating by Mikrotik i.e. 10V-30V. I am not keen to use the 12V thing because sometimes cables are too long and i don't want voltage to be an issue.

What about the high voltage protection. I can see that PB360 -24 has cut off at 31~35 Volts which still means it excceeds the rating by Mikrotik i.e. 10V-30V. I am not keen to use the 12V thing because sometimes cables are too long and i don't want voltage to be an issue.

LM7824.

What about the high voltage protection. I can see that PB360 -24 has cut off at 31~35 Volts which still means it excceeds the rating by Mikrotik i.e. 10V-30V. I am not keen to use the 12V thing because sometimes cables are too long and i don't want voltage to be an issue.

LM7824.

Do I need to connect a LM7824 with every POE??

And how many 433ah can i power up from ad-155-24??

Does the Ad-155 have multiple outputs cause I see it to have only one 24V and one 5V??

Do I need to connect a LM7824 with every POE??

Yes.

And how many 433ah can i power up from ad-155-24??

Spec Sheet says max current draw is 25W.
http://routerboard.com/pricelist/downlo ... file_id=69

I've run 4 without problems, but you should be able to go up to 6.

Does the Ad-155 have multiple outputs cause I see it to have only one 24V and one 5V??

It just has one power outlet. You can run that into a DIN rail distribution block and then plug all your breakers and other devices into the block.