To estimate how long a 12V 20W solar panel will charge a 200Ah battery, you first need to consider the panel's output. A 20W panel at peak sunlight (about 5 hours of effective sunlight per day) produces roughly 100Wh daily (20W x 5h). To fully charge a 200Ah battery at 12V, you need 2400Wh (200Ah x 12V). Therefore, it would take around 24 days of optimal sunlight to fully charge the battery, assuming no energy loss and ideal conditions.
A few variables are involved like, does the solar panel have a charge controller, what condition the battery is before you start and how much sun is the solar panel receiving.
No set answer to that. It depends on the capacity of the battery, the size and efficiency of the solar panel and the intensity of the sunlight.
That depends on the amp-hour capacity of the battery.
The time it takes to charge a 12-volt battery with a 13-watt solar panel will depend on various factors such as the battery's capacity, its current state of charge, weather conditions, and efficiency of the charging system. On average, it may take around 8-10 hours of good sunlight to fully charge a depleted 12-volt battery with a 13-watt solar panel.
A very long time. I would guess 48 hours of sunlight at the very least. Even that may not be enough to fully charge the battery. It really depends on how much amperage the solar panel is putting out.
I did not locate a solar panel laptop itself, but there are solar panel laptop charger for the laptop battery. these will last many years and substitute for buying a laptop battery every year.
Most likely not. In order to charge the battery to its nominal rated 4.8 volts, youreally need a source capable of more than 4.8 volts open-circuit.You need to take the solar panel and a voltmeter, and measure the output voltageof the solar panel with no load connected to it. If it's more than 4.8 volts, then itwill charge your battery.But . . .That's not saying anything about how long it will take. 0.4 watt is not an awful lotof power, and your solar panel will not even deliver that much before its outputvoltage sags to 4.8 . So I would think that this solar panel will not be an acceptablecharger for that battery.
You need to provide many more details. So assuming that the panel voltage is reasonable, the panel is clean, it is sunny and the panel is pointed at the sun. Then it will take about 225/7 hours to charge the battery. About 300 hrs. But in fact charging is only about 85% efficient (charge at 14 V get energy out at 12V or so). This ups the charge time to maybe 350 hrs or so. Charging can be improved by inserting a MPPT charger between the battery and the panel. This bit of electronics decouples the battery voltage and the panel voltage allowing the panel to be operated at its' most efficient voltage. That might knock off 15% of charge time bringing you back to 300 sunny hours.
It depend on the capacity of the battery. This question has been expertly answered by others on wiki-answers with explanations of the physics of it.
A very, very, long time. Only a guess but I would venture to say at least 15 hours.
A solar panel on the roof, absorbs light from the sun to produce electricity, sufficient to power the home, and charge a battery in a generator. When rain clouds impede the sunlight or when nightfalls, the battery powered generator is automatically switched on, to power the home, and also power-up its own battery, so that if solar light for some reason does not happen to reach the home's solar panel for a very long time, the generator can keep going.
Yes, you can. The alternator on your boat is voltage regulated, so it will automatically taper off the charge current to maintain about 14.6 volts regardless of what the solar panel is doing. The panel is not regulated if you do not have a charge regulator installed between it and the battery, but at 5.5 watts, the most it will put out is about one half an amp. As a rule, you can take the current rating on a panel and divide it by 50, and as long as the amp hour capacity of the battery is not less than the resultant number, you do not need a charge controller, the panel will never put out enough current to overcharge the battery. If the sun is shining while the motor is running, the alternator will simply reduce its output enough to accomodate the panel, no other action is required. If you want to read more about this, look in the library for a book called, "The Complete Battery Book," by Richard Perez. Take care, Rudy