Solar Panel

[sport95hd]

what is a good solar panel to keep my batteries charged when in storage?
how to mount without drilling holes in my roof i have a fiberglass roof

[HarryStone]

search the 'going green' sub forum in the 'RV Forums.' Lot's of info there about solar.

[Gary RVRoamer]

One that has sufficient wattage to match the parasitic load on your batteries. In other words, any panel that is big enough to replace whaever amp-hours are lost every day. That of course assumes you have some reliable amount of direct sunlight each day while in storage. The biggest & most efficient solar panel won't help without direct sunlight for at least a few hours each day.

So, you need to provide some data about how much discharge your batteries suffer while in storage, and how much daily sunshine can be expected. From that you can size a panel (watts).

Note that a battery disconnect on the ground terminal of the battery bank would probably cut the loss to near zero and you might not need any panel at all. But if there is stuff daining power, you might need a big-ass panel placed in full sun so that it can deliver lots of amp hours.

[Rocky Larson]

3M makes a double sided tape for securing solar panels. My panels (in service for 12 years) are held on by 3M5200 adhesive. Just need a few days for it to completely cure.

[530ktm]

Originally Posted by Rocky Larson

3M makes a double sided tape for securing solar panels. My panels (in service for 12 years) are held on by 3M5200 adhesive. Just need a few days for it to completely cure.

I used this same tape on a previous coach with two large panels mounted to fiberglass roof. It is also known as VHB tape, Very Heavy Bond tape. Probably a good 100 watt panel will keep things charged if nothing is dragging the batteries down. You need a decent charge controller also to monitor the input so you do not over charge things.

[Persistent]

The general rule is to fully charge the battery bank for 14 to 18 hours. Next disconnect the batteries at the battery terminals. Flooded cells in good condition should last for 6 months before needing another 14 to 18 hours of charging. Keep terminal voltage above 12.4 volts to prevent sulfation and freezing.

Battery University https://batteryuniversity.com/

How does the Lead Acid Battery Work? https://batteryuniversity.com/learn/...ased_batteries

Charging lead acid batteries https://batteryuniversity.com/learn/...d_acid_battery

AGM https://batteryuniversity.com/learn/..._glass_mat_agm

How to Charge and When to Charge? https://batteryuniversity.com/learn/...o_charge_table

How to Store Batteries https://batteryuniversity.com/learn/...tore_batteries

Summary of Do’s and Don’ts https://batteryuniversity.com/learn/..._battery_table

[Isaac-1]

Since you are only concerned about battery drain during storage, get a big enough one that you can put on the dashboard and let it charge through the windshield. If you are facing south you should only take about 30% performance hit from being inside the windshield.


Something like https://smile.amazon.com/DOKIO-Monoc...dp/B0748GKHZ8/