Increasing Solar Panels 45watt OEM to 200watt

[rlbarkleyii]

I have a factory installed 45 watt solar system that is on my Winny Journey. I assume it was designed to keep a trickle charge on coach batteries when in storage? I want to increase the number of panels on the system to bring it to 200 watts. My thought is that this would support electronics such as computers, cell chargers and the like when boondocking. I can not locate a control box for the OEM charger unless it is built in to the utility controls in the hallway. That only has a LED to indicate that solar power is being produced.

My question is, would the increase in panels and wattage require a new control? Can the solar 200 watts go straight to the coach battery without a control of some kind?

[dickandlois]

rlbarkleyii,

Charging batteries with solar power is great on the environment and for batteries. Charging and maintaining batteries through solar will result in better battery performance and longer battery life. With solar chargers rated 15 watts or more, it is recommend one use a controller. It's no surprise that if a battery reaches full charge, but the sun keeps on shining, you risk overcharging the battery. Solar controllers regulate the voltage output from the solar panel and prevent batteries from being overcharged.

Rich.

[bobndorine2]

You need a controller. I use a Blue Sky which works great. You also must use larger wire to carry the amps safely.

[desertdeals69]

It might be difficult to expand the system you have. I would install a complete new system using a MPPT charge controller. The larger the wattage the higher the charge current. What kind and size is your battery bank? I have 6 agm golf cart batteries and 600 watt panels and it will charge up to over 40 amps, depending the state of charge of the batteries and the amount of sunlight. I have parked under a LED parking lot light and charged 5 amps all night!

[evolvingpowercat]

200 watts will take a lot of roof space, you may want to evaluate what you have room for on top and still be able to access things on your roof you might need to someday.

You will need a solar panel charge controller that can handle about 7 amps charging current per 100 watts of solar panel minimum, chances are high that Winnebago used a small solar charge controller that will have to be replaced. Or you can leave the OEM system as is and just add in a totally separate new system, this may make more sense

Winnebago might not have even used a solar charge controller with a small 45 watt panel, as their engineers might have thought this output less all the small constant load drains (refrigerator 12 volt board, propane gas sensor) would be below the "trickle charge" threshold of 12 volt lead acid batteries where they don't lose water.