Quote:
Originally Posted by itakatz
The information on the battery is the total capacity, not current (therefore it is measured in mAh, which is milliamps per hour. 1920 mAh means you can get a current of 1920 mA for one hour, or 192 mA for 10 hours, etc. But it doesn't give information about the maximal current you can draw from the terminals without damaging the device. Since each LED needs about 20 mA for regular operation, I guess 2 or 3 won't be a problem. Btw, they must be connected in parallel, since the output is only about 4V, which means the currents will be additive (20mA per LED).
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The general rule for the type of battery used in the Kindle is, the peak current draw is twice the mAh rating. This is a "surge" rating not a continuous rating.
Which is why Kindles have batteries with a 1500 mAh or larger "storage capacity" rated battery.
The 3G modem/radio card draws 3 amps (1500 mA * 2) while actively transmitting. (these are "burst" transmissions done at the battery's "surge" rating).
The battery in a Kindle is
not the size it is because Amazon wanted you to be able to go a month between re-charges. That's the smallest capacity battery that will run the 3G card.
None of which applies to what the limit of the current draw from the top lamp connector might be.
That is a "switched" power connector.
The limit is that of the electronics used to do the switching.
If the (solid state) switch is only rated at 20ma - then you can only pull that much current from the connector.