Monday, October 1, 2012

Cordless telephone chargers (Solar)

Three years ago (Feb 2009) I bought the following Panasonic cordless telephone system from Amazon consisting of 4 cordless telephones; a base unit and another three separate chargers. It works great and can't complain about it.  
Targeting to transform my house into a Zero-energy building, it was time to look at this small energy consumer and upgrade it to charge the telephones (not the base telephone since this needs power 24/7) using small solar panels.
I happened to have previously bought some submersible fountain pond water pumps from eBay for another project. I did use the small pumps but never had found any use for the 7.2v 1.12W panels, well until today! These panels match exactly the chargers for the separate cordless telephones. I plugged in a panel instead of the charger and it has worked OK for the past 45 days, i.e. the small solar panel was enough to keep the telephone batteries fully charged. Obviously, one panel per telephone is needed and the panel placement (in full sunshine) is of great importance to get maximum output from these small panels.

Below is a panel, 7.2v 1.12W
I have posted here details for building a simple battery based power supply for the base station.