• Pretzilla@lemmy.world
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    8 months ago

    That is a cheap shitty knock off scam panel, just looking at the specs. it claims:
    Power: 5W
    Working voltage: 5v
    Working current: 0-380mA

    but of course, you won’t get 5w from 5v * 380mA, only 1.9w based on the specs.

    the square area via the specs is 125cm^2 (assuming that’s the panel, not the package!)
    and the realistic maximum power possible is 200w / m^2, so 125 / 10000 * 200 = 2.5w for that dinky panel.

    get yourself a decent version of this if you really need a portable version.
    something more like this, or catch a better version on sale:
    https://amzn.to/3VqsztI

    Then there are these kick ass USB monitors that will tell you exactly what’s going on during charging:
    https://amzn.to/4ao74xU

  • NigelSimmons@startrek.website
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    8 months ago

    Are you going to wire the solar to a usb connector and plug it into the bank charging port? This is probably the safer way of approaching this.

    Also, sometimes the quoted voltage is a “nominal working voltage” kind of deal. Grab a multimeter and see how many volts the solar cell puts out at noon without any load, it might be in the 8v range that could pose an overvoltage problem to your bank (that’s expecting 5v ) if it fills up completely.

  • cooljimy84@lemmy.world
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    8 months ago

    Just cause it has a USB plug doesn’tmeans its regulated output… I suspect its just welded across the output of the panel…

  • pearsaltchocolatebar@discuss.online
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    8 months ago

    It might be, or it might not be. It depends on several factors.

    The first thing you’re going to want to do is check the output voltage of the solar panel. You can either use a multimeter or a dedicated USB tester. You’re looking for a stable voltage of 5V ± 0.2v. If your voltage is outside of that range, you’re going to want to throw a voltage regulator in between it and the battery.

    While the battery might be able to handle a larger range, there’s no guarantee that it will, so you could very well end up frying the circuitry, or it just never charging because you’re outside of the range.

    You can get solar charge controllers for under $20. That’s just an example of what to look for.