I'm building an RV system that will use 48 volt battery and a 3000 Ah inverter/charger/mppt. It seems they all require a minimum of 120 volts for the PV but I will have less than that, only 2 panels initially. Can I step up the voltage from the PV array to more than 120 volts?
How to step up 2 panel PV series to 120 volt minimum for inverter?
- Thread starter DaveTyp
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justinm001
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What does? MPPTs need about 5-7v above charging voltage to work. This is like 60-65v.
They do make boost mppts that'll allow lower voltages
They do make boost mppts that'll allow lower voltages
I take it you meant 3000w AIO. Used to be a few out there that would work but I am not finding anything now with a quick search. Mostly they are at least 5000w at 48vDC and higher PV voltage. It is not really practical to try and step voltage up from your panels in order for the AIO's SCC to step it back down.
However there are SCC's with MPPT that can be used and go with an inverter /charger instead of an AIO.
why only 2 panels?
48v battery and 3000w inverter deserves a few more panels
guess that's one of the downsides to using 48v takes a bit longer to get up a decent charge in the mornings unless you got a zillion panels
3000w Inverter is still in the 12v range you may be better severed looking at staying 12v
The only real money saving going to 48v is in the panels and controllers.
Put inverter as close to battery as possible wire size is manageable and affordable
if you stay with 48v and not enough panels ... use a separate MPPT connected to the battery.
my plan is 2 large 400w panels on the rear section ... nice fit there
then second string of 4 or 6 smaller 200w panels .... Tetris layout using a second controller.
25 foot trailer with standard crap all over roof
48v battery and 3000w inverter deserves a few more panels
guess that's one of the downsides to using 48v takes a bit longer to get up a decent charge in the mornings unless you got a zillion panels
3000w Inverter is still in the 12v range you may be better severed looking at staying 12v
The only real money saving going to 48v is in the panels and controllers.
Put inverter as close to battery as possible wire size is manageable and affordable
if you stay with 48v and not enough panels ... use a separate MPPT connected to the battery.
my plan is 2 large 400w panels on the rear section ... nice fit there
then second string of 4 or 6 smaller 200w panels .... Tetris layout using a second controller.
25 foot trailer with standard crap all over roof
Thanks, that is what I am seeing too. Yes, AIO
yes, mine is 26 foot. It seems that mine too can only get 2 of the big panels unless I build a rack over the whole roof. That then is why it is hard to make the 120 volt PV minimum. It would be really nice to just get something like the EG4 AIO inverter for less than $700, but then it creates my PV voltage issue. Yes, I guess I could just not use the MPPT in the AIO, but then it seems like I should just go a different route.
Utopia for me, I believe, would be the AIO that can use 2 big panels in series.
justinm001
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This is a prime reason why AIO aren't ideal in many scenarios.
You'd be much better with a Victron inverter, cerbogx and mppt then call it a day. Might be twice the price but 4x the stability and longevity. On top of better equipment you'll get an auto transfer switch so can just wire shore to victron to panel to outlets.
Since you're considering only 120v option you could run 10/30/50a shore and Victron will powerassist the 3000w so your 15a becomes over 30a and your 30a is more than 50a as needed then goes back to charging the batteries.
If willing to go 12v you can get the Victron 2x120 inverter and get 240v/50a (12kw) shore pushed through to 2 120v legs inside the RV and never worry about power when on shore.
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