Hi I need some help,
I live in a rural area where i have a gate which was until now automated,
It was powered by a simple solar panel (60w) and a victron 20A charge controller(pwm)
the battery is a 30ah lead acid battery.
For the past 7 years this worked perfectly.
Crime has increased sadly and even though the solar panel was secured, thieves managed to steal it together with the charge controller, and completely vandalizing the remaining cables,
My house is about 100meters away and I have a shed that is a little closer to the gate (70 meters away) the shed has solar for lighting.
Replacing the solar panel and charge controller in the same manner would be stupid and I have some ideas, other people in the area have had their equipment stolen even though theirs were mounted on long poles, their equipment was also stolen,
I would like to charge the battery at the gate from the solar at the shed shed, but i need some advice, I was thinking of getting the BlueSolar PWM Charge Controller (DUO) for the shed and running a cable from the charge controller to the battery, but i dont think that would work or will it?
(From what I have read I’d need really thick cables,)
my other idea is to use a LM2596S current limiting buck voltage regulator and limiting the current to lets say 100ma that could charge the 30ah battery slowly but this might be too slow and i’m not certain how to choose what cable i should use,i googled voltage drop and got even more confused, and in essence why I’m here, i’ve tried to google and i am just not finding answers,
The last option i could use is to run an AC cable up and put a charger connected to the battery from the house, for me this isnt a great solution and i’m trying to avoid this option.
It will be ok to charge the battery slowly as the gate isnt used too often,
my other idea is to keep with the original setup but then to cast the solar panel within a concrete block, and make it impossible to remove, having it on the ground in a pasture may make it invisible to thieves,
Any ideas and suggestions would be really welcome,
I would stick with what you had (as it was obviously reliable for over 7 years) but mount a solar powered IP/4G camera to your system. These camera’s come with their own solar panel which charges the camera directly and are extremely easy to install.
I have one at home and it’s operated faultlessly for 5 years. It not only keeps the thieves away but also triggers my spotlights - i.e. PIR.
There are so many of these camera’s in the market place now and they are extremely cost effective.
I’ve got a REOLINK but there are plenty out there.
All the best.
If you think about it, I don’t believe having AC and an AC socket at the gate is such a bad idea…
Almost all around us is powered with AC and having AC there is opening a lot of opportunities you may have or want in the future.
In the end, it’s a point of entry on your property.
But this is just me, you may have other reasons for not wanting AC there…
Thank for for your reply, I did have a camera there, however the thieves took the long way around and disabled the camera from behind, two nights before the incident there was a suspicious car that scouted the gate installation, I had buried the battery deep underground and the vegetation had grown around and over it so they didnt find it, if i put the solar back I am considering casting the solar panel in concrete, I know that’s not great from what I’ve read (for cooling), but i could not find anyone else that has done something similar, if i put it back like it was they simply going to remove it again, I am considering having a sensor to trigger the alarm system in the house. Preferably I’d like to trickle charge the battery from the solar at my shed, my thought was to use a 1mm,^2 cable with a 100ma charge, but really need someone to help me with the math
Maybe install a larger solar panel on the shed to mitigate voltage drop and increase the voltage and run the DC PV from there to a suitable MPPT solar charge controller at the battery location. As long as the current is kept relatively low, 4mm2 should be fine to deal with the voltage drop. The absence of the panel may just deter the baddies too.
That’s exactly what I have been thinking, but the problem is the math calculations, i could use a boost converter to up the voltage, to lets say 48V?.. but then on the other side what charge controller should I use, i’d like to keep the costs down,
The thing i dont understand is the voltage drop, I took a cat5 24 awg network cable to test, i joined two pairs together and the other two pairs together, and measured the volts on the source and at the other end, the voltage drop was 0.2volts but that’s with no load at all, i’m guessing that if i put a load on it it will drop to 0 volts and heat the cable up. Hence me wanting to do the math, and work things out correctly, but I just have nobody to ask hence my post here
You can download the Victron Toolkit app to your phone and that has a voltage drop calculator in it. There are numerous other on line voltage drop calculators. Use these to see what voltage you get if for example you have a 48V 5A panel in the shed to see the voltage at an MPPT at the battery. A quick calc for 100m one way distance with 4mm2 cable is 5V so could be done.
Thanks,
By the looks of everything the cost of a 4mm PV cable and the cost of the charge controllers, I might as well go with a 2.5 mm AC cable and run 230V AC, which I really wanted to avoid.
My last option which I cant see that anyone has done is to cast a solar panel in concrete,
it really upsets me that one has to go to these extremes.
Just a last question if i give 12v output from one charge controller into the PV input of another charge controller, will that be enough to charge a battery on the remote side?
No, because the voltage input to a charge controller has to be at least 5V higher than the battery to start charging and remain 0.5 or 1.0V higher during charging.
You could put a DC to DC charger at the gate to boost a 12V supply which will be low due to voltage drop.
How was your panel mounted? I don’t think casting the panel in concrete is a great idea. What you could do is cast a grill or cage over the panel instead, depending on your local conditions. Beware of shadows. Or having the panel at the shed is not a terrible idea. I have panels mounted about 100 meters away from my chargers and batteries. I used 25mm² cables. My voltage drop is negligible. I used online calculators which were very simple.
NB: Where I live, the thieves simply saw the bars
DC to DC charger with MPPT @ battery (RV type in a small box) run a cable 2x 1.5 100m from a panel. Voltage drop only occurs when power is flowing - loss ca 5 - 30 % (.1 - 2A) who cares… if you only need the battery occasionally and just topped up.
So general consensus is to just run at the moment some (2.5mm2 or more) cables from shed to gate and you’ll see later for what you’ll be using them. DC or AC.
