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736382DA-D9C1-4130-8D7E-1A504952E1B5.jpeg I've built a 5x7 enclosed trailer into a tinyhome/mobile office which I plan to travel/live in extensively.
Everything I've done so far was based on very limited space (and sacrificing a lot of creature comforts) as I was/am just looking for a roof over my head so to speak.
So here's the details, while I'm more confused today then ever.
Four (4) 100 watt flexible panels, flush mount on roof. Ipmax - 5.5amp, Vpmax - 18volt, Isc - 5.1amp, Voc - 22volt. I installed/built a solar thermal/PV/roof cooling system and put heat into water tanks below.... it runs well and I can keep my panels/roof in the 39-42C rang effectively. (50 ft 3/8" compressor hose in roof, 1gpm 1.5 amp pump, temp sensitive relay for those interested... plus 1" insulation, aluminum bubble wrapped & 3/4" tongue and grove pine keep it all cool inside).
To fit all the panels on, they are all in portrait layout to one another... was hoping to wire 2s2p (cut/rewire as necessary).
I intended 2 battery banks (with a 2 battery/bank) enabled PWM charge controller... but that only works to 240 watts and I was unhappy with tongue weight from a tongue mounted 27 Group deep cycle marine battery. So that's been scraped.
I have four (4) 12 volt 35 amp-hour batteries (I custom made a frame to support them under the frame & just in front of my axle (single). They are from Harbor Freight (Thunderbolt Magnun) and I have wired them in parallel with 4 AWG (heavy jumper cable wire). I've connected them to a 1000 watt continuous pure sine wave inverter (2000 watt surge). On the positive side... less then 10 ft of double AWG #6. On the negative side... single AWG #6 plus a chassis frame common. I have a 100 amp Circuit Breaker on the pos side.
Noting other threads, just saw how AGM/SLA batteries are not best to be wired in parallel... but i don't have space for different battery sizes, nor can I switch to a 24volt system.
I now have a 40 amp MPPT charge controller. 100 volts max. OOYCYOO 40A MPPT Solar Charge Controller 40 amp 12V/24V Auto,Max 100V, 520W / 10400W Input with LCD Display for Sealed, Gel, Flooded Lead-Acid Battery (The New Upgrade) https://www.amazon.com/dp/B07NXS4HVG..._PrgvDbY4WZRNP
I ran AWG 12 THHN from my CC to my batteries (less then 10ft), but this may be undersized.
I fully understand the additive aspects of the panels in series or parallel or 2s2p (the last was my preference), but I am absolutely lost now on how the CC is converting/modulating/etc with the MPPT and how this gets sent to my batteries. My 4th panel (just arrived today - it was defective & that was a 3+ week ordeal to get a replacement) so today I temp wired 1 panel, 2, 3 and 4 (checking numbers on the CC) and noted total watts was not adding as one would expect with the addition of each. Something like 40W, 70W, 95W and 120W (even though it was getting sunnier over the 20 minutes I tried the combinations.)
Then I tried 2s2p and with voltage/battery out (as per the CC) pegged at 13.6-13.8 volts I only got upto around 10-11 amps. Actually, it was less then that before I added some "leisure light/house" Load of 4-5amps drawing directly from the CC.
I really don't understand this MPPT CC, expecting lots of heat off the back if the batteries are reading full and with no direct LOAD off the CC... but I can't find any (or where watts are going to). It would also appear I need to up my CC to Battery wring... probably 6 AWG, if the MPPT is going to limit voltage out and bump current up on the chance I start producing 400 watts (400/13.8 = ~29 amps).
At this point... I feel like I am in salvage mode (just trying to get this all functional - without just buying more pieces/parts that may or may not solve the mess I've created.
Any advice is welcomed.
FYI on build photos... www.instagram.com/hansworldtravels
Everything I've done so far was based on very limited space (and sacrificing a lot of creature comforts) as I was/am just looking for a roof over my head so to speak.
So here's the details, while I'm more confused today then ever.
Four (4) 100 watt flexible panels, flush mount on roof. Ipmax - 5.5amp, Vpmax - 18volt, Isc - 5.1amp, Voc - 22volt. I installed/built a solar thermal/PV/roof cooling system and put heat into water tanks below.... it runs well and I can keep my panels/roof in the 39-42C rang effectively. (50 ft 3/8" compressor hose in roof, 1gpm 1.5 amp pump, temp sensitive relay for those interested... plus 1" insulation, aluminum bubble wrapped & 3/4" tongue and grove pine keep it all cool inside).
To fit all the panels on, they are all in portrait layout to one another... was hoping to wire 2s2p (cut/rewire as necessary).
I intended 2 battery banks (with a 2 battery/bank) enabled PWM charge controller... but that only works to 240 watts and I was unhappy with tongue weight from a tongue mounted 27 Group deep cycle marine battery. So that's been scraped.
I have four (4) 12 volt 35 amp-hour batteries (I custom made a frame to support them under the frame & just in front of my axle (single). They are from Harbor Freight (Thunderbolt Magnun) and I have wired them in parallel with 4 AWG (heavy jumper cable wire). I've connected them to a 1000 watt continuous pure sine wave inverter (2000 watt surge). On the positive side... less then 10 ft of double AWG #6. On the negative side... single AWG #6 plus a chassis frame common. I have a 100 amp Circuit Breaker on the pos side.
Noting other threads, just saw how AGM/SLA batteries are not best to be wired in parallel... but i don't have space for different battery sizes, nor can I switch to a 24volt system.
I now have a 40 amp MPPT charge controller. 100 volts max. OOYCYOO 40A MPPT Solar Charge Controller 40 amp 12V/24V Auto,Max 100V, 520W / 10400W Input with LCD Display for Sealed, Gel, Flooded Lead-Acid Battery (The New Upgrade) https://www.amazon.com/dp/B07NXS4HVG..._PrgvDbY4WZRNP
I ran AWG 12 THHN from my CC to my batteries (less then 10ft), but this may be undersized.
I fully understand the additive aspects of the panels in series or parallel or 2s2p (the last was my preference), but I am absolutely lost now on how the CC is converting/modulating/etc with the MPPT and how this gets sent to my batteries. My 4th panel (just arrived today - it was defective & that was a 3+ week ordeal to get a replacement) so today I temp wired 1 panel, 2, 3 and 4 (checking numbers on the CC) and noted total watts was not adding as one would expect with the addition of each. Something like 40W, 70W, 95W and 120W (even though it was getting sunnier over the 20 minutes I tried the combinations.)
Then I tried 2s2p and with voltage/battery out (as per the CC) pegged at 13.6-13.8 volts I only got upto around 10-11 amps. Actually, it was less then that before I added some "leisure light/house" Load of 4-5amps drawing directly from the CC.
I really don't understand this MPPT CC, expecting lots of heat off the back if the batteries are reading full and with no direct LOAD off the CC... but I can't find any (or where watts are going to). It would also appear I need to up my CC to Battery wring... probably 6 AWG, if the MPPT is going to limit voltage out and bump current up on the chance I start producing 400 watts (400/13.8 = ~29 amps).
At this point... I feel like I am in salvage mode (just trying to get this all functional - without just buying more pieces/parts that may or may not solve the mess I've created.
Any advice is welcomed.
FYI on build photos... www.instagram.com/hansworldtravels
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