Is there an easy way to know if you are actually getting 5 watts from a solar panel advertised at 5 watts? Some bargain panels look as good as pricey ones and I know there are differences, but the main one I would like to check out is if it delivers what it claims. Thanks for whatever you can tell me.
How to check a solar panel for it's wattage?
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well, one way to figure, Watts
Watts=Volts X amps, or P=ie. You need to clean the pannel point it to the sun and measure the amps (in series) then measure the volts ( in parellal) multiply the two together that will give you Voltamps or Watts. Maybe 70 to 80% of stated value John
Watts=Volts X amps, or P=ie. You need to clean the pannel point it to the sun and measure the amps (in series) then measure the volts ( in parellal) multiply the two together that will give you Voltamps or Watts. Maybe 70 to 80% of stated value John
You will have to make the measurments
as stated in the preceeding post but you must make them at the same time. If for example you have a 5 watt panel you will need a 5 watt 12 volt lamp bulb for a load on the panel. the ampmeter goes in series with the load and you read the voltage across the load. Then multiply volts times amps to get the actual power output. Much of the difference in cost is the quality of the weather proofing on the panel. if it say weather resistant, just how well does it resist?
as stated in the preceeding post but you must make them at the same time. If for example you have a 5 watt panel you will need a 5 watt 12 volt lamp bulb for a load on the panel. the ampmeter goes in series with the load and you read the voltage across the load. Then multiply volts times amps to get the actual power output. Much of the difference in cost is the quality of the weather proofing on the panel. if it say weather resistant, just how well does it resist?
You can use your digital multi-meter in series
to measure the current flowing from the solar panel to a light bulb. Just don't use your multi-meter to try to measure current coming from your battery banks or chargers or anything of higher current. For higher currents, you need a shunt. Cheers, Bob s/v X SAIL R 8
to measure the current flowing from the solar panel to a light bulb. Just don't use your multi-meter to try to measure current coming from your battery banks or chargers or anything of higher current. For higher currents, you need a shunt. Cheers, Bob s/v X SAIL R 8
It is a trickle charger
It is clearly a trickle charger at 5 W. Lets see P=IV so I=P/V=5/13.6=0.368 Amps!!!! To answer your question, connect it to the battery and record the voltage (the sun must be shining on the panel) on the battery. Disconnect the panel (circut breaker, fuse, wire etc..) and read the voltage on the battery. If the voltage went down then it is charging (at the max of .368 amps). For the record a 100 AH battery @ 50% discharge would take 50AH/.368A=135 Hours of full sun or something like 27 days to reach full charge. Maybe it is a lunar charger!
It is clearly a trickle charger at 5 W. Lets see P=IV so I=P/V=5/13.6=0.368 Amps!!!! To answer your question, connect it to the battery and record the voltage (the sun must be shining on the panel) on the battery. Disconnect the panel (circut breaker, fuse, wire etc..) and read the voltage on the battery. If the voltage went down then it is charging (at the max of .368 amps). For the record a 100 AH battery @ 50% discharge would take 50AH/.368A=135 Hours of full sun or something like 27 days to reach full charge. Maybe it is a lunar charger!
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