PV Gap

Johnnie Said:

Why wont my blackberry charge using a solar charger?

We Answered:

Have you considered that the solar charger might not be generating enough electricity to charge the blackberry? I'm not sure which blackberry you have, but check around on the net for the power requirements of the blackberry, then check and see what the output is of the solar charger.

Oscar Said:

Can someone help me with Solar Panels?

We Answered:

Please ignore the "2000 hour" answer. Obviously, a terrible mathematical error was made. If you are thinking of running this cooler directly off the batteries, Please be advised that your cooler is most probably AC and the batteries are DC. You will need an inverter to change the DC to AC on this system. Your cooler runs 80 watts at 120 volts. This equals .66 amps of current.

Your source of power, however, is only a 12 volt battery. You still need 80 watts of power from your battery. To get .66 Amps at 120 volts, you will need 6.6 amps at 12 volts. Now take your 115 amp-hours and divide by 6.6 and you get 17.4 hours. But you not done....

Battery-type inverters, together with other losses and inefficiencies on the system, will only yield about 80% from battery to appliance. add 20% to 6.6 and you now need 7.9 amps from your batteries. Your new number is 14.56 hours. But you are still not done....

It is very hard on batteries to run them down to the reserve. At this rate, the battery will only have a 2 to 3 year life. To prolong the life of the battery, you should never run it down below a 50% DoD (depth of discharge). Now your number is about 7.3 hours of running your cooler. Give yourself some wiggle room and say 7 hours of cooler operation before you need to charge the battery back up.

One more quick note. the 115amp-hours is at a 20-hour rate. Our discharge rate was about 14.5 hours. Because this less than 20-hours, the amp-hours will go down. Most batteries also list an Amp-hour at 5 hours. You will probably be about half-way between these two numbers.

Byron Said:

Can one use a small AC unit to cool tent? How?

We Answered:

Sorry, but a 5,000 BTU window unit is about as small as you can get for a unit that has a compressor in it.Normally a 5,000 BTU unit draws about 1200 watts with the compressor running. When the unit cycles or it reaches the desired room temperature the compressor shuts off leaving only the blower fan running at approx. 20 to 30 watts.In order for your unit to run a min. of 90 minutes the compressor would need to cycle approx. every 5 minutes.

Mae Said:

solar energy question?

We Answered:

The converter comes with ever solar installation you will ever buy. Now... the hard part is to actually put 100m^2 of solar modules on your clients lawn every time you need to use the drill or electric rotary saw.

Might be a bit expensive, too. To make 2kW of power you would need solar panels worth $10,000. That is kind of a lousy idea, especially since you would keep breaking them all the time (they are not meant to be moved after installation).

To put it into perspective: on a good day, as a contractor, you will use between 10 cents and a couple dollars worth of electricity.

Terry Said:

Can chargers with an Output Voltage of 5.5V / 8.4V / 12V , charge a video camera with a 9.6V ?

We Answered:

No, the selection of your chargers isn't close enough to charge the 9.6 volts correctly. The 5.5 volt and 8.4 volt won't fully charge the camera and the 12 volt will overcharge and damage the battery in the camera.