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You can charge it with ANY wattage 12 volt solar panel.
The wattage of the panel will determine How Many Hours of sunlight you'll need to charge the 12 volt battery, so the next piece of information you need to consider is: what are you going to use that 12v battery for, and how quickly do you need it charged up?
Here's the math-
To figure out how many hours it will take to charge the battery, first figure out the output of the solar panel by dividing it's WATTS by it's Volts, which will give you it's output in AMPS. So. .
a 15 watt panel DIVIDED by 12v = 1.25 amps
Next, read the Amp Hour rating on your 12v battery. If we use a 50 amp hour battery for this example. . .
DIVIDE 50 amp hours [required to fully charge the battery] by the 1.25 amp output of the solar panel = 40 hours of direct sunlight to charge the battery. Then add another 10% of time to his number, so figure 44 hours.
Some more examples:
5watt/12vpanel=.42amp and 50amp hr/.42amp=119 +10% = 131 hours of sun
30watt panel works out to 22hours. 50watt=13hrs 80watt=about 8 hrs.
Of course all of these times are based a 50amp hour 12v battery.
BTW, I'm no expert... i just found this equation online 5 mins ago because i was wondering the same thing myself. . Now could anyone tell me how figure out quickly my computer or light or whatever will drain that 12v battery??
[Answer final question from above]
To determine how quickly your battery will drain, let's assume that same 50AH battery. You wish to run 2-5W 12V lamps for about four hours each evening and use your small laptop for an hour which has a 50W draw at 18V, so about 80W at 12V. Your use will be 80W/12V=6.7AH + ((2*5W)/12V)*4 hours=3.2AH, or a total of about 10AH per evening. If you allow the battery to discharge to 50% before wanting to recharge it, you can run as described for about 3-3 1/2 evenings per week. If you concurrently have a 30W solar panel charging the battery for 4 hours per day, you will be keeping the battery fully charged it (you will be putting back 10AH per day). This allows for a couple of cloudy days.
Hope this answers your question. Remember, watts/volts=amps. Multiply each load by the number of hours you need it to run to get ampere-hours. Add all these results together to determine the total draw on the battery.
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∙ 11y ago
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Can you charge a battery with solar panel producing 245 watts?
You can't charge the battery with those 245 watts unless they are being 'pumped into' the battery at a higher voltage than the battery puts out. If you can exceed the voltage of the battery, that 245 watts will definitely charge a battery.
How many watts solar panel do you need to charge 12v battery?
To charge any battery the voltage of the input must be more than the battery's output.
How many watts solar panel need to charge 12volts 7ah battery?
1 watt will do the job.
Can you charge a battery with solar panel producing 80 watts?
You sure can! I charge a marine battery with a 75 watt panel and it goes from a fairly good discharged state to fully charged in about four days.
How much power would it take for a 20 watts solar panel to charge a 12v battery?
about 500watts/meters of irradiance
How many watts solar panel do you need to charge my 12v 100amp battery in 6 hours if you use 5.5amp a hour?
There is too much information there. Charging a 100 amp-hour battery fully would take 18 hours at 5.5 amps, or 6 hours at 16.67 amps. At 5.5 amps the power would be 12x5.5 or 66 watts, and this is the rating of the solar panel required. That would be about 0.4 of a square metre.
How many watts are required to start a 7 HP 12 VDC motor you want to start the motor on solar panel?
For calculation purposes 1 HP is equal to 746 watts. So you have a total of 746 x 7 = 5222 watts. The amperage will be A = W/V = 7222/12 = 435 amps. You can not start the motor directly off of the solar panel. You would need a large 12 VDC parallel connected battery bank to obtain the amperage capacity to start the motor. The solar panels would be connected to the battery bank and used to charge the batteries after the start.
Can you leave a 5.5 watt solar panel attached to a boat battery while running the engine in other words alternator and solar panel charging the battery at the same time?
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
How many watts are in one solar panel?
It all depends on the size
How many watts in a solar panel?
It depends on the model, please specify.
How much energy does a solar panel generate?
I assume they come in different sizes, but a typical commercial solar panel generates about 50 watts.
How much solar energy does the sun give out?
About 1,000 watts per square meter of solar panel
