Anyone have a solar cell phone charger?

David Trammel's picture

In relations to the California Canary thread and lack of power, does anyone have an alternative way to charge your cell phone? A dead phone cuts you off from so much like information and contact with family.

I have a small hand crank radio/flash light with a solar cell, that has a usb port to charge things. Though half an hour of hand cranking didn't increase the bars on my cell phone. I wondered if anyone has real experience with alternative ways to keep your cell phone charged.

I've read where enterprising people set up carts with solar panels and offer cell phone charges for money in an emergency.

lathechuck's picture

Today (Jan 1, 2020) I tested both the Nomad 7 and the ES500 as chargers. My phone is an LG 440G flip phone, which charges at 430 mA at 5 VDC (as measured by the USB Doctor device (see below)), and both solar devices were up to the challenge. Conditions: bright sunshine, low sun angle, solar panels vertical (propped indoors, against double-glazed south-facing windows), late morning. The Nomad 7 is rated to produce 7 W of DC power, the ES500 rated to charge a phone at up to 5W (5V@1A), but that includes drawing down the internal battery, which it will charge from solar at just 1 W.

I also use them to recharge the batteries in my GP-5/SSB AM/FM/shortwave every-day carry radio, which draws 250 mA.

The ES500 is pocket-sized, includes a 5000 mAh battery, and has a built-in LED flashlight. Walmart is currently selling it on-line for $11.89 ("list price: $21.89"). (Walmart has a variety of such solar panel / battery / flashlight / USB charger units. I see one that claims "300,000 mAh", which might be plausible as "10,000 mAh battery, which you can recharge 30 times before it wears out." That CAN'T be the actual battery capacity.) The Nomad 7 has no internal battery, and lists $60 from Goal Zero, but can also charge/run 12V devices, and can probably support phone charging under less favorable conditions, since it has much greater panel area.

The crucial factor to consider is that a solar panel needs to be completely in the sunshine. Any shadow is likely to substantially reduce its output. 10% coverage of my roof-top solar panels, when snow builds up at the bottom, is as bad as complete coverage. The angle of light hitting the panels also has an effect, but not as much as a small shadow.

A possibly helpful accessory is called "Charger Doctor", which plugs into a USB port. It displays the present voltage and current flowing through the device to whatever is plugged into its own USB port. So, while you're cranking a generator or sitting in the sunshine, you can see immediately how much current is getting to the phone. ($7.50 at, though currently out of stock).

Blueberry's picture

Have a Big blue folding panel and a Dork meter great for camping and hiking. i find it best to charge a battery pack and charge the phone off the battery pack can run a led camp light off the same battery pack. Meter

lathechuck's picture

But, I can see how "dork-meter" might apply to those of us obsessed with our USB devices...

Looking at the description of the Drok, I think there's some potential misunderstanding. It mentions measuring "capacitance", which is a term usually used to describe a capacitor, when I think they meant to say "capacity", which refers to batteries. The distinction may be too subtle for Chinese-to-English translation. Capacitance has units of coulombs per volt (usually expressed in microFarads), while capacity is just coulombs, but usually expressed as mAh (milli-Amperes * hours).

Blueberry's picture

Ok so I like plug and play the jackery giant is about 3 years old ( have 2 ) .The cost has gone from under 20 to 35.99. The HF battery has under 100 cycles but looks to be KID PROOF. It was out in the rain over 2 inches. With a coupon cost is under 20 plus tax. Camp light NOT KID PROOF need to fold wires over switch and tape to switch

Sweet Tatorman's picture

If you own an automobile your least cost option will be a charger that plugs into the auto cigar lighter receptacle. Auto chargers with the 5V usb receptacle can be had for $10 or less.

lathechuck's picture

Looking at a car as a mobile generator is an approach that I've considered for powering my ham radio station in a grid-down situation, if I can't use my big solar panel (because of clouds or night-time), but of course it assumes the availability of fuel (or "charge", if it's an electric car). The ES500 solar panel that I describe above is not much more than $10.