Hi ;
i was watching a clip from tiktube and i realized that there is possibility to connect the router board to a battery .
here i would like to ask , is it really possible to connect my RB333 to a battery directly ? , so it will be running for long time without the problems of power oscillations from the generator .
also if it possible can i use a battery like 12v / 70 Ah or 130 Ah ?
how can i connect the battery to the RB and is it possible to use the battery with the Poe ? .
waiting feedbacks .
with best regards .
Hi ;
thanks for your reply .
what is the max cable length for the PoE ?
sometimes we use a large 12V float battery and a DC-DC converter to step it up to ~22V for long length PoE and multiple radios.
what do you mean here by float battery ? , and the DC-DC converter is to raise the voltage ?
i am going to use 2 R52 and one EMP 8602s with my RB333 .
The RB voltage ranges are typically annoying as 12V is close to the lowest they will run on and 24V (two batteries) when charged and on float are around 28V, close to the upper limit!!
do you recommend to use two batteries ?
hence we have a lot running on 3 x 6V batteries , ~ 18V
sorry i didn’t get this .
with best regards.
We run several RBs off 12v batteries and boost the voltage with one of those laptop power adapters that takes 12v from a car cigarette lighter and boosts it to a selectable voltage from 15 to 24v. The one we use can deliver 3.5A at 20v, 3.3A at 24v but there is a ‘bigger’ one that can deliver 6A at 24v from a 12v input.
We have one set at 19v which delivers 18v at the board 85m away. There’s clearly some overhead - tho’ I’ve never measured it and the thing only gets slightly warm - so in a situation where every amp you can generate from solar or whatever counts it might not be a solution, but it’s a cheaper solution than another battery where there is a bit of surplus power
Greetings!
I hope you can do it, because I am already. I use solar and a charger with low-voltage load disconnect set at 11.5v. I have checked the RB133, 333 and 433. All do ok.
EDIT: Normis, if you read this, the voltage monitor on the RB333 is great for this!! I have heard a rumor the new RB433s may have that feature. True? If not, put in my request please.
hence we have a lot running on 3 x 6V batteries , ~ 18V
6x2=12x2=24
6/2=3x2=6
6x2=12/2=6
6/2=3/2=1.5
Math doesn’t work. How are you getting 18 volts?
Hi ;
he say it clearly 3 batteries each one six volts . 
hence we have a lot running on 3 x 6V batteries , ~ 18V
but the real question here , you mentioned many voltages in your example . but which voltage should be used and the RB will work in perfect way ?
the current will determine the time which the RB will be running in , but what is the best voltage ?
is it 12 volt , 24 volt ? some say it should be 48 volts .
also if it possible ,could you post a photo to your DC- DC converter ? what are the input voltage and output voltage and current should be ? 
with best regards .
And I said it clearly. 3 6 volt batteries do not equate to 18 volts.
Hi ;
no connect the three batteries in series , the current will be the same but the voltage will be the sum
with best regards .
I have to agree, 3 times 6 = 18. I’ve checked a number of calulators and they all agree 
what kind of charger will charge the battery while it is being discharge by the load at the same time?
Your nominal 18V (3 x 6v in series) will actually be about 21 volts when fully charged and sitting at float voltage, which is a great place to run one of the newer RBs.
What most people call a 12v system is actually 14v, and 24v is actually 28v. It DOES make a difference, don’t ask me how I know…
George
Hi ;
still need to know what is the voltage for the battery should be used to power a RB333 ?
another question , do i have to connect the battery to DC-DC converter or it is possible to connect the DC injector for the PoE directly to the battery ?
with best regards .
I stand corrected. I was taught each step in the series doubled the voltage which is incorrect.
i.e. 12 + 12 does equal 24
but 12 + 12 + 12 does not equal 48
Nice guide Kijomabb. One question about your setup though… when the AC main is up, is the load is going to draw power from both the adaptor and the battery?
Is the bulb now not consuming more energy then the unit (rb) you want to keep alive? If we consider a rb333 board with 3 radios consuming roughly 18W max the overall performance for a given battery pack is shortened by more the 55-70%!
To make up the capacity you need more then double the battery, gone the low budget!
rudy
I hate UPS because of it’s very short back-up time.
Back to my earlier question… Since the load is connected parrallel to 2 power sources (the adaptor and battery), and assuming that both power source have the same voltage, the load should draw half of its power from the battery and half from the adaptor. So, even when the AC main is up, power will still be drained from the battery. Please correct me if Iam wrong.
The purpose of the bulbs is to prevent the adaptor to dump too much current to the battery after a long outage. The battery might explode. If you do not wish the battery to power the bulb, then put a diode between the battery and the bulbs.
Unfortunately, the purpose and the effect are not both helpful. The complaint, and rightfully so, is that you are powering the bulb while charging the battery. My solar panels are rated in watts, and not very cheap watts at that. Some of those would light the bulb instead of charging the batteries. 
True. I did a test with a 500VA UPS which has a 9AH battery in it. On the UPS my test rb333 with three working radio’s stayed on for about 3 hours.
Took then the 12v straight from the battery (disconnected the ups electronic) and the same rb333 stayed up some 12 hours! 4 times longer!
Ok, in this case the battery would be drained more, until the rb was dropped of due lack of power, which was somewhere in the region of 11 volts. I don’t know when the UPS stops taking power from the battery in case of backup function but it could be it stops earlier not to damage the battery. May 11,5 or 11,8 or so.
But I presume that since we have no coil loss in the two transformers used to create 220 from 12 and then 12 from 220 the economy of running 12V supplies straight from a 12V battery works much better.
Back to my earlier question… Since the load is connected parallel to 2 power sources (the adaptor and battery), and assuming that both power source have the same voltage, the load should draw half of its power from the battery and half from the adaptor. So, even when the AC main is up, power will still be drained from the battery. Please correct me if I am wrong.
No, that´s not the case, but it basically depends on the current the adapter can supply. If the adaptor can supply for example 6Amps while the device only takes 4A, the battery will be charged with 2A. (charged battery).
If the battery is drained yes, in that case the battery will consume all current it can get (in this case 6A) so nothing is left for the device.
This situation is both bad for the battery (high loading current on deep uncharged batteries is very bad) and the device (its probably stays dead).
In case your adapter can only supply 3A while your device is consuming 4A, then indeed the 1A short will be supplied by the battery and the battery will drain.
The higher the battery is charged to its maximum, the less current it will take, the more is left for other devices.
So it means you do have to balance the complete setup well.
The bottom line is that the adapter should be able to supply the max. current the device will take PLUS the charge current the battery will take maximal in case it has been drained.
The charging current to the battery should be managed. If the battery has been drained completely it should be charged slowly first while load current can go up while charge level rises. According the specs of the battery (in healthy condition, not a 20 years old one!) you can then find a max. charging current.
When the battery is nearly ´full´ the load current should actually be brought back to a so called ´trickle charge´ to keep it in best condition while not over charging it.
You can buy battery chargers and or regulator in price ranges from ´come with a pack of cornflakes´ to values exceeding the value of your fully equipped routerboards. You can pick which are the ones more likely to do a good job. (And extend your battery life and protect your gear.)
Hope this helps…?
Rudy
I think you are missing my point here. You see, the battery is hooked to the load at all time. My question is, since a complete circuit exist between the + and - terminal of the battery (through the load, of course), how do you stop the battery from moving electron to the load when AC main is up ?