The following article which explains a 20 cell phone charger station using solar power was requested by Mr.Bertini. Let's learn more regarding the request and the proposed set up procedures.
Discussing Solar Panel Installation in Villages
"Good day Sir,
I am so interested on your DC to DC for cellphone charger circuit . But I could order the complete mobile charging circuit from you because I can find other parts locally (solar panel, battery charger and batterry). How much this can cost me? this is for solar mobile phone charging station to charge up to 4 cellphones at once.
Could you also build mobile charger circuit that can support up to 20 mobile phones at once for charging?
On the other hand , can you build a battery cellphone charger circuit using up to 20 pieces of universal battery charger, this solution would be charge most mobile phone battery available in the whole market?
All my design would power by solar panel. I would like to purchase all my mobile charger circuit componenets from you.
A prompt answer would be appreciated .
I appreciate your interest and business.
The costs will depend on the quantity of the order, kindly let me know what will be your minimum quantity. once I know that I'll be able to calculate the costs.
I'll be able to make all that you have requested, won't be a problem for me.
Awaiting your kind reply!
Best Regards, Swagatam
Good day Mr.SwagatamThank you for your kind email . I am developing Solar Mobile phone charging for rural village in my location( Africa).
As start , let us work on solar mobile phone charging system and solar mobile phone battery charging system. the finished product would be assembly locally.
1st - Solar mobile phone charging solution
this would charge up to 20 mobile phones at once . Autonomy would 5 days(if this is not sun). Please tell me the size of the solar panel, battery charging circuit, battery and mobile charger circuit board. so i would need as start about 30pieces to 50 pieces of mobile charger circuit board. for each output, i would like to use multi charge usb retractable cable( 10 connectors), also send me the cost of cable (50pieces)
2nd - Solar mobile phone Battery charging solution
This would be able to charge up to 20 pieces of batteries for mobile phone at once. Autonomy 5 days. Please tell me the size of the solar panel, battery charging circuit, and the universal battery charger circuit board. tell me the type of DC universal battery charger that i will need. so i would need as 30 pieces to 50 pieces of universal battery charger circuit board and 50 pieces of DC universal battery charger. the finished product would be assembly locally.
Kindly send me the cost of required items as above.
Mr. Bertini Monthe
I can suggest you a simple and effective way of completing this project with minimum hassles.
Thank for your prompt reply . Yes you can go ahead with your own suggestion. As soon as you finish with the design, kindly send me the link of your blog for me to view the details.Hope you can also supply me electronics components if I need some? Do you speak French ? Looking forward to hear from you soon. Kindest.
Application Engineer , Solar Visionary and Writer.
The Circuit Design:
According to me, assembling the entire station using ready made units would be a lot better idea instead of building the individual circuits. This approach will be quicker, easier and will avoid many difficulties which are normally a part of manufacturing processes. The cell phone charger requirement can be solved by procuring and installing 20 nos. ready made cell phone chargers and by connecting their mains inputs in parallel to a small solar inverter. Charging a cell phone Li-Ion battery can be very critical and requires high grade smart chargers with auto shut-off features for charging them safely.
Manufacturing such smart charger requires a lot of expertise and experience, so I won't recommend making these units.
Instead 20 nos. second hand cell phones may be procured (example NOKIA1280) and may be used as Li-Ion battery holders cum chargers.
All cell phones have a built-in smart charger which charge the involved battery with utmost care and automatically shut off the process when the charging is completed. The display provides the necessary information with a beep sound once the charging is completed, so that's a cool way of charging the Li-Ion batteries without taking any risks.
The cell phones may be used normally when they are not being employed for charging the above batteries. The following block diagram illustrates the different stages that may be employed for installing 20 solar powered cell phone station:
How to Bulk Charge Cellphones using Solar Panel in Villages
The first four blocks represent a standard solar electrification set up. The solar panel voltage is first tailored to the required battery voltage through a solar charger/controller module.
The output from the solar module is then fed to an inverter battery for charging it.
The charger/controller automatically cuts off the charging of the inverter battery when it's fully charged and resumes when it reaches the under charge threshold level.
The battery is used for driving the inverter whenever required.
The output of the inverter is used for charging the proposed cell phones and the Li-Ion batteries.
20 cell phones would roughly consume 20 to 30 watt hour of power, so a 100 watt inverter would adequately serve the purpose.
A 40 AH car battery is recommended here, which would happily satisfy the 5 day autonomy requirement.
The solar panel is not very critical here, a 60 watt panel having an open circuit voltage of 30V and a short circuit current of 3 amps will be quite suitable for the present application.
The solar charger/controller is the only equipment that may be manufactured at home. I have already discussed one such circuit in this 3 step charger circuit article, which may be effectively employed for the present application (the transformer should be replaced by the solar panel terminals).