PV Gap

Catherine Said:

how do you charge a solar powered calculator?

We Answered:

A light bulb won't do it as fast as full sunlight, but it will work if the light is bright enough.

Marjorie Said:

Why don't we have a solar powered graphing calculator yet?

We Answered:

You are right solar cells do improve over time. However the cheapest ones (as used in calculators) haven't changed much. Hence their efficiency is still very low. So in order to get the power you need for a decent graph display you need a big area of solar cells. Unfortunately big cells are rigid and easily damaged. Multiple small cell would be okay but they would take up alot of space and look ugly. Hence there are no cheap serious calculators that are solar, yet.

Samuel Said:

Solar Powered Calculator Help Please (10 Points)?

We Answered:

It will use the solar whenever it can, even charging the battery. THe battery gets used only when there is not enough light.

Jim Said:

My calculator is solar powered -how do i recharge the battery in it?

We Answered:

No u dont have to do all this.... it will charge everything a light source is around.
:)

Brent Said:

My solar powered calculator was packed away in a box in the basement for 3 1/2 years?

We Answered:

You need to go and look at small installations that collect solar energy during the day - these include garden pathway lights, decorative hangings, and security motion lights. Outside the house where I am visiting and typing, there is a decoration with hanging glass balls with LED lights inside and a disk at the top with solar cells and batteries. Shown at the bottom of this page http://www.mikegigi.com/firthm/chimes.ht…
It receives sun for much of the day and turns on at dusk - it glows for about 3 hours, gradually fading.
Outside my kitchen window is a lantern shape with solar cells on top and a AA size battery inside with a single LED - it glows like a candle for a 2-3 hours dimly in the night.
Pathway lights, which I used to sell, have a post with a dozen or so solar cells and a battery pack underneath with a wire leading to 3-4 LED post lights so the cells can be put in the sunlight as long as possible and the lights can be put under trees, etc. We regularly used to kill off sales or get them back because people wanted them to last all night and they were good for about 4 hours. Okay in the summer, but having the lights die at 8:30 pm in the middle of the party didn't function.
Security solar only turn on the lights when someone is under them, thus lasting longer.
And all of these are using LED lighting. So to do stuff in your house and have it be safe lighting, you need to change out the incandescent for focused LED's, put in low voltage wiring to get from the batteries to the lights, have substantial batteries matched to the watt-hour needs of the lights and then have enough solar cells to charge the batteries even on days when the sky is cloudy and output is way down.