Solar Trickle charger -- any good?

I have the same model on the front of my trailer. it does a good job of keeping the battery "topped off". I used to have the battery be low after a month of sitting, one time it was dead. since I installed the solar battery maintainer, the battery has always had a full charge, I installed it about 3-4 years ago!

No you can`t dry camp with it! but it does what it is intended to do.

I tried a 2watt charger for my pickup which sits a lot in the winter. It didn't help much. Now I have a 5 watt charger and it keeps up with whatever draws on the batteries when shutdown for weeks. yes, I know-drive it occasionally. That is fine when circumstances allow.

The 2 watt module may just keep up with typical self-discharge of a single battery but I doubt it's an effective solution. I would be looking more towards 50w-60W to get the job done.

I used one similar to that with little luck. However, location is everything since I wasn't getting many hours of direct sunlight where I was having to park the RV. If I had parked in full sunlight, my results may have been different.

Reviews are good. I have a solar charger on the roof of my MH, that was a factory install. Does nothing for the house batteries, Friend shifted his over to his engine battery and said it worked. Less drain on chassis battery.