Archerite
New Member
My solar panels are wired in parallel and rated for 12V, but actually give more like 17-24 volts on most days. For various reasons I do not want to connect them in series so this is the voltage I have to work with. Mostly because of the various shadows during the day on the balcony where the panels are. But also to keep the array compatible for "direct solar input" into my EcoFlow river.
So the real question is how to efficiently convert/invert/boost from the 12V batteries to 48V? Right now I have a few cheap boosters that do it but they are only 1A at 48V. It's something but I would like to use a bit more. Since I got into the victron ecosystem with the MPPT and smartshunt I looked at their Orion DC-DC converters...but they do not have 12V -> 48V. At least not directly! There are 12 -> 24 and 24 -> 48 converters and so that is what I have got now to experiment with.
But is there another way that is more efficient to go to 48V? Not including connecting batteries in series as then I could not charge from solar at 24V anymore.
Everything is still experimental after only a few months since I started this. Already learned those inline glass fuses are terrible and just melt away!! Maybe I should get different fuses...but I just don't trust them anymore! Other than that I keep an eye on the expected amps and wire sizes I use and so far no mayor issues! 
The only thing is that my solar components are a bit far away from my "workshop/hobbyroom" and I would like to use the power directly instead of first charging USB powerbanks or my EcoFlow River and keep draging them back and forth! This is how I started researching options and what I would need to get the power over a distance of about 15-20 meters. My first thoughts and topic for research was using my existing ethernet wire and the official PowerOverEthernet specifications. Those components are not cheap and for meaningfull power I would need 802.3bt which specs 60-100watts over 100 meter of cat6 wire.
I did get some items from Amazon to play around and tinker with..and while it's working on my desk I have not hooked it up to the actual network wires yet. It's just a active 802.3at PoE+ injector and a few splitters. It's enough to power the most basic things like a Ubiquiti USB adapter to charge a phone or tablet. But that's only 15 watts and the 30 watt splitters are a lot more expensive!
So looking closely at how PoE actually works and what voltages and currents are involved I started thinking about just hooking 48V directly onto the wires. I don't need data on this link so I could use all four pairs directly! Four wires each for positive and negative! There would ofcourse be a voltage drop but by putting it in a variable bench powersupply and limiting the current...and putting that into another MPPT does make it possible to charge my second battery bank. As said....all experimental on my desk only! But while I think using the ethernet wires as described...and a max current of 2-3AMPS that is still a lot of losses over the wire length and the converters.
So today I decided to instead go for dedicated 4mm2 copper wires directly between the batteries and my "workshop"! There would still be a voltage drop and max current restriction on it but at least it's going to be higher than on ethernet wires, and no risk of plugging 48V into a network device! I plan on a separate fuse or breaker for just this wire. I think it's between 5-10A max anyway...
The other secondary reason for wanting 48V is the posibility of replacing the powersupply in my PoE switch one day and running it directly from DC power. That would mean less load on an inverter...or maybe not requiring an inverter at all!! But that is for far into the future as the network rack consumes more than 150-200watts at the moment and I have much less solar panels in total! And the batteries required would cost a lot too....so not going to be possible this year. and most likely the next!
The only thing is that my solar components are a bit far away from my "workshop/hobbyroom" and I would like to use the power directly instead of first charging USB powerbanks or my EcoFlow River and keep draging them back and forth! This is how I started researching options and what I would need to get the power over a distance of about 15-20 meters. My first thoughts and topic for research was using my existing ethernet wire and the official PowerOverEthernet specifications. Those components are not cheap and for meaningfull power I would need 802.3bt which specs 60-100watts over 100 meter of cat6 wire.
I did get some items from Amazon to play around and tinker with..and while it's working on my desk I have not hooked it up to the actual network wires yet. It's just a active 802.3at PoE+ injector and a few splitters. It's enough to power the most basic things like a Ubiquiti USB adapter to charge a phone or tablet. But that's only 15 watts and the 30 watt splitters are a lot more expensive!
So looking closely at how PoE actually works and what voltages and currents are involved I started thinking about just hooking 48V directly onto the wires. I don't need data on this link so I could use all four pairs directly! Four wires each for positive and negative! There would ofcourse be a voltage drop but by putting it in a variable bench powersupply and limiting the current...and putting that into another MPPT does make it possible to charge my second battery bank. As said....all experimental on my desk only! But while I think using the ethernet wires as described...and a max current of 2-3AMPS that is still a lot of losses over the wire length and the converters.
So today I decided to instead go for dedicated 4mm2 copper wires directly between the batteries and my "workshop"! There would still be a voltage drop and max current restriction on it but at least it's going to be higher than on ethernet wires, and no risk of plugging 48V into a network device!
I plan on a separate fuse or breaker for just this wire. I think it's between 5-10A max anyway...The other secondary reason for wanting 48V is the posibility of replacing the powersupply in my PoE switch one day and running it directly from DC power. That would mean less load on an inverter...or maybe not requiring an inverter at all!! But that is for far into the future as the network rack consumes more than 150-200watts at the moment and I have much less solar panels in total! And the batteries required would cost a lot too....so not going to be possible this year. and most likely the next!
So the real question is how to efficiently convert/invert/boost from the 12V batteries to 48V? Right now I have a few cheap boosters that do it but they are only 1A at 48V. It's something but I would like to use a bit more. Since I got into the victron ecosystem with the MPPT and smartshunt I looked at their Orion DC-DC converters...but they do not have 12V -> 48V. At least not directly! There are 12 -> 24 and 24 -> 48 converters and so that is what I have got now to experiment with.
But is there another way that is more efficient to go to 48V? Not including connecting batteries in series as then I could not charge from solar at 24V anymore.
