Re: solar cell phone chargers
Car batteries are sort of similar. A lot of people seem to think that you can jump dead battery and in ten minutes it's all charged up and ready for action but it doesn't work that way. Say you have an 800CCA battery and a 100A alternator. That would take 8 hours to fully recharge that battery but then you have to figure in what the engine is drawing to run and it's not like the cars of yesteryear that were all mechanical and could run on a magneto. They need electricity to run. Add in lights, A/C and a heater fan and you've loaded that alternator up pretty well. You could easily break 10 hours of running to fully recharge a car's battery with its alternator.
Re: solar cell phone chargers
Quote:
Originally Posted by
streaker69
Figured I'd show the math just to make it clear.
The panels on those units output 1.5W at around 6VDC. To find the current we divide 1.5/6=.25A or 250mA
The battery in the OP's post is an 8000mA/H. To find the time, and since we're using like units, we can just divide 8000mA / 250mA = 32 hours.
That means you'd need 32 hours of perfect sunlight to fully recharge the battery pack from the supplied panel.
That is of course a perfect model without account for any other losses. It would actually take more than that.
How long if I put it under a sun lamp ?
Re: solar cell phone chargers
How big are these cell phones?:confused: I can plug mine into the lighter of my truck , or battery tender plug of my motorcycle and in an hour or so , it's full.
MC battery is AGM 12v 500cca 32amh
Re: solar cell phone chargers
Quote:
Originally Posted by
abner13
How big are these cell phones?:confused: I can plug mine into the lighter of my truck , or battery tender plug of my motorcycle and in an hour or so , it's full.
MC battery is AGM 12v 500cca 32amh
Do the math on what the output of the connector is. I have the ones in my vehicles now that are 3.4A for output it's common to see 2.1A devices.
10000ma / 3400ma = 2.94 hours to a full charge from dead.
From an 80% charge.
2000ma / 3400ma = .58 hours
Re: solar cell phone chargers
Quote:
Originally Posted by
streaker69
Do the math on what the output of the connector is. I have the ones in my vehicles now that are 3.4A for output it's common to see 2.1A devices.
10000ma / 3400ma = 2.94 hours to a full charge from dead.
From an 80% charge.
2000ma / 3400ma = .58 hours
I didn't say it was a smart phone. I still have a 15yr old Samsung flip-fone. It's a phone only. No data , net , text , etc.
Yeah , it would take a bit more to fully charge my Moto G7 Power.
Re: solar cell phone chargers
Quote:
Originally Posted by
abner13
I didn't say it was a smart phone. I still have a 15yr old Samsung flip-fone. It's a phone only. No data , net , text , etc.
Yeah , it would take a bit more to fully charge my Moto G7 Power.
Smart phone doesn't matter. It's based upon the battery and the input current. The same formula can be used for any battery that needs charging.
Re: solar cell phone chargers
Quote:
Originally Posted by
streaker69
Have you seen who's president? There's a lot of foolish people out there.
Let's assume perfect conditions:
3 Panels is now 1.5W@6V: 4.5/6=750ma
You need to recharge your phone from the device and that uses 2000ma.
2000ma / 750ma = 2.67 hours of perfect sunlight to recover the energy lost by charging.
I just want people to realize the marketing is all under perfect conditions, something that rarely happens when you're outdoors. The panels would need to be stationary under full sun to charge properly. That means you can't be under tree cover, you can't be hiking with it hanging off your bag and you'd have to adjust it's angle to the sun while it's charging.
Maybe you kids do things differently than when I backpacked in my teens. But in my day we used to hike during the day, and sleep at night. We were never still for 2.67 hours during the day. Those things may be fine for stationary camping, but actual real hiking, not so much.
Rubber band chin strap. Wear it like.
Re: solar cell phone chargers
Quote:
Originally Posted by
DukeConnor
How long if I put it under a sun lamp ?
Longer than plugging it in next to the lamp.