We have a couple jet skis we keep on a lift at the lake, and we found that if we skipped two or three weekends going up there, the batteries in the jet skis may or may not start the machines. When that happened, instead of riding, we'd be dragging out the battery charger and long extension cord to charge the batteries up.
I bought a couple small solar chargers (available everywhere for about $15), figuring they would be perfect for insuring the batteries were always charged up and ready to go. The problem, however, was figuring out an easy way to mount them. A couple weeks ago I finally took the time to mess with them, and came up with a simple yet nice mounting solution.
Feel free to adapt it to your particular situation.
Solar battery charger
8" long mending strap/plate
Primer and paint
Step 1: Get the "Stuff" Together
The most important thing you need is an inexpensive solar charger. The ones I used were about $15 each at Harbor Freight, but they are available lots of other places as well. They only put out 1-2 watts, but remember, we aren't really trying to charge a dead battery here. We are just seeking to keep the battery from draining as the watercraft sits. These little chargers work well for that.
In addition to the charger, you will need a galvanized steel mending strap/plat. The one I bought was about 8" long and about 1 1/4" wide. It's not important that it be exactly this size. It just needs to be strong enough to hold the charger on the boat lift or pier without getting bent easily.
You will need some 1/2" plywood to make a base for the solar panel. I had a scrap I found in the shed that worked fine.
And finally, you will need some bolts/nuts to fasten the plywood to the solar panel, to fasten the plywood base to the mending plate, and to fasten the mending plate to the pier or boat lift (when you see the pictures it will all make sense!)
Step 2: Cut the Base to Mount the Solar Panel On
So the basic approach here is that we are going to cut a piece of 1/2" thick plywood just a little longer than the solar panel so that we can mount the solar panel on it. However, BEFORE we mount the solar panel to the plywood base, we will mount the mending plate to the wooden base.
Start by measuring the length of the solar panel and then cut a piece of plywood about an inch longer than the panel (this will give you a half inch of overhang on each side). I also cut the corners off of the base so there wouldn't be sharp corners to catch anything on. I also primed and painted the wooden base just to protect if from the elements.
The picture shows the base laying on top of the solar panel before I cut the corners off, painted it, or mounted the solar panel to it.
Step 3: Mount the Mending Plate to the Wooden Base
Once the wooden base is dry, mount the mending plate to it as shown. I used galvanized round-head bolts and tightened them tight enough to sink the round heads into the wood. When you are done with this step, it should look as in the picture.
Step 4: Mount the Solar Panel to the Wooden Base
Now that you have the base mounted to the mending plate, bolt the solar panel to the base as shown. Basically you end up with a T-shape. The solar panel is mounted to the wooden base and the metal mounting plate sticks down from the middle.
Step 5: Mount It to Your Lift
Using the mending plate as a guide, mark and drill two holes to mount the mending plate to your boat lift. Be sure to position it such that you can bend the bracket to get maximum sunlight on it. Also be sure to position it on your lift so that it will be close to the battery on your jet ski. In my case, we have one jet ski with the battery in the front and one with the battery in the rear, so I positioned the solar panels accordingly.
The bolts will need to be long enough to go through the plate and the lift, and also allow room for washers and lock washers. In my case, my lift was 2" tubing so I used 2 1/2" bolts. Once mounted, it should look like the second picture.
Step 6: Bend It Backward to Catch More Sun
Once you have the unit securely to the lift, the last step is to firmly grasp the ends of the wooden board and slowly and firmly bend it back (bending the mounting bracket) so that the solar panel tilts at a good angle toward the sun. You will be bending it so that the solar panel is covering the top of the lift post (see picture).
To finish it nicely, you can zip tie the wires to the lift post if you like. When I am not using the charger, I tend to clamp the terminals to the ends of the wooden board. When we are done with the skis for the weekend, we simply pull them onto the lift, remove the seat/hatch, and hook the charger up to the batteries. There is enough cord to accommodate the canvas covers,
The chargers take in sun all week, keeping the batteries and nice charged and ready for our next visit!