Amorphous Solar Panel — 7 Watts

I keep mine attached to my battery 24-7. No issues at all. Been hooked up for several months now.

No. It wont do much charging, but you can leave it plugged in.

This solar panel does not have to be disconnected at night. It features a blocking diode to prevent the 12 volt battery(not included) from discharging during nighttime hours.

Yes, but what would work better is two batteries, hooked positive to positive, negative to negative, brought to a full charge, and THEN put a panel on each battery (the same as two on one battery).
The reason I suggest two batteries, is the deeper a battery is discharged, the more current it takes to bring it back up to a full charge. Adding a second battery will buffer the drain you put on your setup, allowing for a faster full recharge.

Yes I have 2 hooked in my house right now on a single battery. but im thing of going two 4 and see how it works.In full sun I get any where from 13.8 to 20.8 volts and that seams darn good to me.But I mite add another battery to get more amps.

Two of these seven watt solar panels can be hooked up to a single battery. To be safe a charge controller should be used to prevent over charging.

Absolutely...

This solar panel can be connected to a battery when a power inverter is being used. This panel provides the battery with 7 watts per hour in ideal conditions(placed in direct sunlight, not cloudy). Your battery charge will drop accordingly if the items running off your inverter draw more than 7 amps.

Yes you can hook it up to the battery. The power inverter will emit a beeping sound when the batteries go below a set voltage amount.
I think one 7 watt solar panel is a bit small in watts to use it to charge a vehicle battery in less it is more or less just a Trickle charger for more than one day.. However, if you do want it to do that you need to get a Charge Controller of some type shown in the catalog. It may take a couple days to charge a vehicle battery using this small unit.
I have three 7 watt panels going through a charge controller and charging two Aux batteries in my Motor home.
I keep the Power Inverter hard wired to the batteries, however I do not use the inverter unless the batteries are fully charged.
It takes my three panels up to two days to fully charge them.

I have one hooked up to cover the drain on my battery for the exact same reason. The battery is never disconnected And I have no issues what so ever. In My instance I mounted a pipe flange on the tongue of the trailer. the panel on a painted and sealed piece of plywood, another flange centered on the back of the plywood, a 45 degree elbow on that flange and a eight foot pipe in between the panel and tongue (2 4 ft pieces and a coupler) . I painted the pipe, and replaced the clamps with rubber trailer type 2 conductor connectors to the battery cable that I already had set up for a maintenance charger, Been running this for four years without a hitch. (my panel DOES have a reverse polarity blocking diode, If the new ones don't they are easy to install, and can be bought for a couple bucks at radio shack as rectifier diodes, you will want something that will handle a minimum of 30 volts 15 amp, to handle any heat issues from sitting in the sun, NOT a small signal diode, other than that, there are no critical specifications, even a 1n9001 or similar would work but if put in the housing it would cook in a relatively short time

This solar panel can be connected to the battery while it's still hooked up to the travel trailer. It will work for your application provided the battery drain from the trailer(including the propane leak detector) is minimal. This panel provides the battery with 7 watts per hour in ideal conditions(placed in direct sunlight, not cloudy).

Yes BUT the big question comes in where you live, and store the boat. first make sure the battery is topped off with DISTILLED water (cooking off water with deposits or chlorine in it will kill the battery). Next The panel needs light to work... use accordingly

Yes, you can use with a boat battery as long as it is 12 volt. It should work, but may not if for some reason there is still a large draw on the battery when idle.

This is basically a trickle charger - as the battery voltage comes up the battery itself will act as the regulator. I have one of these hooked directly to a 100AH deep cycle battery on the boat and it works fine without a secondary controller - doesn't overheat the battery or cause electrolyte loss.

If you're charging a very small wet cell battery or using it for other kinds of work you may need a secondary controller.

This panel, as well as any system under 15 watts, will be safe to use without a charge controller. It has built in protection and will not overcharge the battery.

The temp range for this unit is -40 to 185 degrees F.

This solar panel is safe to use with any 12 volt automotive style battery. The DC output produced by the panel will vary due to sunlight conditions, but a 22 volt output is not abnormal.

This charger will provide .6 amps of 12 volt power. It can work on two batteries that are connected to each other in a 12 system, but a panel on each battery would charge better. A charge controller is not required for solar panel that provides less than 15 watts.

This solar panel cannot be connected directly to a DC fan. If both the DC fan and this solar panel are connected to the same 12 volt battery, the output from the panel is enough to keep the fan running without the battery's charge diminishing.