Super Basic Solar Upgrade
All I want is to install two solar panels with a charge controller to provide charging capability to my existing flooded lead acid batteries. I intend to use these Centennial group 27's until they are...
Forum Discussion
No worries on the two chargers playing together. They will be fine.
Use bigger gauge wire if you can, this will be well worth the time it takes to route new wire from the panel to the controller to the batt. 10 gauge, 12 would be the smallest I would ever run.
Run the two panels in "series" not parallel. They will be more efficient running down the wires, and the MPPT controller can take the 37 volts and convert to the lower 12-14.7 volts needed to charge the batts.
Glass Mono panels are what you want. Any of the ones on ebay are fine, but do not get the flexible ones. Many people prefer two panels instead of one big one. If one goes bad then you are out half..
The Poly panels are fine, but te mono are better for RVing.
You can sometimes run the wires down the fridge chimney, or use a "gland" to get in into the roof. Use "gland" for your search term on ebay. or "entry gland".
Use Dicor Lap sealant, never silicone (hard/impossible to remove) or caulk (cracks).
For a charge controller get an MPPT one. Do not get the $20 ones. IF you find a great deal then they will be $50 range. At least 30 amps. PWM would be OK if you already have it, but MPPT is the most science...
You can make aluminum L-brackets and use VHB (very high bond) tape to tape them to a metal or fiberglass roof, but not to a rubber roof or on top of a rubber coating. You can use self-tapping screws to go through the L-bracket and into the panel (careful to not screw into the actual solar cells or wires or glass) or you can pre-drill / use existing holes and use bolts (stainless steel).
You can screw into the roof also, but use Lap sealant liberally.
The panels on the roof will not see highway speed wind when you are driving highway speeds, there is turbulence on the roof so the forces are not that great so close to the roof. Some RVers use four 3-inch wide L-brackets and adhere them to the roof and the panel. I use 24 inch long angle irons (same shape as L-bracket just longer) and screw to the panel. I have metal roof so used VHB tape to secure to the roof. Leave room under the panel for air flow and for the wires to exit. Cool panels work better.
This is really all you need to know...
Use bigger gauge wire if you can, this will be well worth the time it takes to route new wire from the panel to the controller to the batt. 10 gauge, 12 would be the smallest I would ever run.
Run the two panels in "series" not parallel. They will be more efficient running down the wires, and the MPPT controller can take the 37 volts and convert to the lower 12-14.7 volts needed to charge the batts.
Glass Mono panels are what you want. Any of the ones on ebay are fine, but do not get the flexible ones. Many people prefer two panels instead of one big one. If one goes bad then you are out half..
The Poly panels are fine, but te mono are better for RVing.
You can sometimes run the wires down the fridge chimney, or use a "gland" to get in into the roof. Use "gland" for your search term on ebay. or "entry gland".
Use Dicor Lap sealant, never silicone (hard/impossible to remove) or caulk (cracks).
For a charge controller get an MPPT one. Do not get the $20 ones. IF you find a great deal then they will be $50 range. At least 30 amps. PWM would be OK if you already have it, but MPPT is the most science...
You can make aluminum L-brackets and use VHB (very high bond) tape to tape them to a metal or fiberglass roof, but not to a rubber roof or on top of a rubber coating. You can use self-tapping screws to go through the L-bracket and into the panel (careful to not screw into the actual solar cells or wires or glass) or you can pre-drill / use existing holes and use bolts (stainless steel).
You can screw into the roof also, but use Lap sealant liberally.
The panels on the roof will not see highway speed wind when you are driving highway speeds, there is turbulence on the roof so the forces are not that great so close to the roof. Some RVers use four 3-inch wide L-brackets and adhere them to the roof and the panel. I use 24 inch long angle irons (same shape as L-bracket just longer) and screw to the panel. I have metal roof so used VHB tape to secure to the roof. Leave room under the panel for air flow and for the wires to exit. Cool panels work better.
This is really all you need to know...
