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Best external power pack

anyone every try or hear anything about those solar battery chargers? I have seen commercials about them and am kinda interested........

I assume you mean this solar panels with a build-in battery.

I've such a solar charger with a 3300mAh battery.
Charging the phone isn't a problem :)

But charging the the build-in battery of the solar charger by using the sunshine, that is a problem ;)
It works, but it needs about three sunny days to charge its build-in battery.

The reason for this delay is a general design error of this kind of solar chargers with build-in batteries.
The panel needs the sun, but the in-build Li-Ion battery hates the heat of the sun.

A Li-Ion battery to charge above temperatures of +45C (+113F) will be dangerous, so the charging circuit will shut off the charging when the battery reaches this temperature.
So there will be delays, because when the sun is the brightest the charging of the solar charger will be shut off :(

Far better are solar panels without a build-in battery. They can charge the phone directly or can charge a separate mobile charger's build-in battery for later use.

For such a "stand-alone" solar panel one should choose high quality.
Cheap panels won't become a joyfully toy ;)

Harry
 
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Hi,

I need advise for the following:

Charger A (Li-polymer battery) output : 5V, 1A
Charger B (Li-polymer battery) output : 5V, 500mA
Device input: 5V, 750mAH (Li-ion / Li-polymer)

When using Charger A, some people comment that it will limit the current of 750mAH for the device and the device's battery should be fine since both the charger and device are at 5V. However, some people comment that this will shorten the battery life of the device since it will perform a 'quick charge' using 1A.

When using Charger B, some people comment that the device will draw more current than it can deliver and causes it to heat up and reduces the charger's life. However, some people comment that Charger B will extend the battery life of the device since it performs a 'slow charge'.

I also read that USB pins on the charger denotes if the charger is a PC or a dedicated charger. If it is a PC, the device will limit the drawing current. If it is a dedicated charger, the device will draw more current to charge itself.

I am confused as to who is right and which charger should i be using.

Can someone enlighten me ?

Thank you very much.
 
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You shouldn't buy neither A nor B ;)

A mobile charger with 5V input should have an amperage of 1A or more for fast charging its own battery.
With only 750mA input current the charging of the charger's battery will take its time.

Another item, with your discription, the charger's battery capacity isn't shown (I take it, this 750mAh is a slip of the pen, it means 750mA input current).
Mobile charger' battery capacity should be at least twice as large as the phone's battery capacity.

To be sure, use a mobile charger like the Anker 5600mAh.
Input 5V/1A, Output 5V/1A,
Capacity 5600mAh.
With its microUSB adapter cable it'll charge your phone fast with up to 1A :)

Harry
 
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