My Beach Sand & Cement battery at 5 months.ASF
This shows my “Beach sand & cement battery” still powering a small clock after 5 months. The device sits in my kitchen window and receives direct sunlight in the morning. The clock display will get brighter in the morning and go dimmer late at night. I don’t know the reason that this is happening. The temperature range in my house does not seem to account for it. Perhaps it is receiving solar energy in the morning and storing it. The chunk of cement dried out long long ago. It is just a rock now—-powering a clock.