Best solar trickle charger???

I have a 12 watt one and gave up on it. It was too much trouble keeping it aimed at the sun to get near the 1 amp it is supposed to provide. It was useful for charging flashlight batteries with some trouble hooking them up.

Our 100 watt panel flat on the roof of our class C motorhome, with Renogy charge controller, provides all the electric energy we need in summer but I can’t use it much in winter due to snow on the panel. I simply disconnect the house batteries and check voltage once a month. If down to 12.4 volts I put a charger on them (usually once every 2 or 3 months).

Im on the fence with your concern. I understand that the phantom loads are draining ur battery while in extended storage, but I would just pull the 30A fuse on the tongue before leaving it...problem solved.

If you want to keep it "up and running" and put back more than the phantom loads take out then its going to take at least 25-40W of solar, wiring, charge controller etc to accomplish this. If its a portable system are you confident it wont be stolen?

Unless you want to install a somewhat robust solar system for true charge capabilities I would just install an inexpensive cut off switch and use it in storage. Those tiny/cheap solar "maintainers" are in my mind simply useless in rv's and a cloudy week may mean you still show up to a dead battery. Just my .02

100 watts or less will keep you charged while in storage but why not do it "right" and rig for solar recharging while camping too? Do an energy survey. I'll wager 200 to 300 solar watts.

For the effort to mount a panel I would go at least 100 watts.
Then you can put the RV away without having to worry about a full charge either.

DinTulsa wrote:


That’s on the list as well. I was going to pick up one of the 1/4 turn switches that disconnect the power.

Don't buy the cheap red key type of switch, they take on water and fail quickly. I use a Blue Sea like this.

CA Traveler wrote:
Put a switch on the battery post so that everything is off.

Except your solar tender, of course. :B

IF....your batteries are healthy and fully charged when you park the rig....you should be able to let it sit with little to no discharge over at least 90 days IF YOU COMPLETELY DISCONNECT THEM.

While a switch is convenient, if the batteries are easily accessible, then disconnecting the negative cable(s) works just as good.

P.S. There is no "good" trickle charger. It needs to include a "smart" controller to prevent overcharging. Then it is an automatic battery maintainer.

Put a switch on the battery post so that everything is off.

Lynnmor wrote:
The Battery Tender 021-1164 10W Solar Panel Charger and Maintainer with Built-in 3-step Automatic Microprocessor Controller should work well. Be sure that you always turn off the battery switch whenever the trailer is not in use. You do have a correctly wired switch, right?

No sir,

That’s on the list as well. I was going to pick up one of the 1/4 turn switches that disconnect the power.

The Battery Tender 021-1164 10W Solar Panel Charger and Maintainer with Built-in 3-step Automatic Microprocessor Controller should work well. Be sure that you always turn off the battery switch whenever the trailer is not in use. You do have a correctly wired switch, right?

To maintain the charge on your batteries 20 watts should be sufficient. Here's one available on Amazon for $58.06:

https://www.amazon.com/ECO-WORTHY-IP65-Solar-Panel-Polycrystalline/dp/B00PFGP0EA/ref=sr_1_4?keywords=20+watt+solar&qid=1551790029&s=gateway&sr=8-4

It includes a charge controller which will prevent overcharging.