Looking for a small solar panel

I'm looking for a small panel (portable is a plus) for charging batteries. Anything that could do AAA-D or a cell phone would be great. Does anyone have any recommendations?


  • BB.BB. Super Moderators, Administrators Posts: 32,804 admin
    Re: Looking for a small solar panel

    With solar power, you really need to know the amount of power you will need (in watts or watt hours), how much sun you have, and the voltage/current needs of the charging devices.

    For example, here is a CCrane battery charger that is ~7"x5"x2.5" and weighs almost 3/4 of a lb...

    Outputs around 150 mAmps at 5 volts... The typical AA rechargable AA NiMH battery is around 2,000 mAmps at 1.5 volts.

    This charger can two AA batteries at a time--that works out to:

    2,000mA/150mA=13.3 hours minimum...

    In summer, the typical sunny region will have about 5+ hours of sun per day--so it will take you three days to recharge to AA NiMH batteries.

    If this meets your needs--great. If not, then you are looking at buying a much larger charger and solar panel to go with it...

    For example, I have a 1 hour fast charger for 4xAA/AAA battery batteries.

    The transformer is rated at 15.5 volts a 1.3 amps (~20 watts).

    The charger comes with a car charger adapter--assuming it can take the voltage from a standard "12 volt" solar panel (solar panel Vopencircuit of ~21 volts is much higher and could damage the battery charger without some sort of voltage regulation circuit), then I would be looking at a 20 watt panel with Vmp=15.5+ volts... This setup will recharge 4xAA batteries every hour or two...

    At our host's store, a 20 watt 12 volt panel will cost around $200 (without shipping) and you would be carrying an 20"x17"x1" framed piece of glass around (and just about as fragile).

    So--there is the range of possibilities--you have to figure out your needs and how much you can pack (if the system needs to be portable).

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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