maemo.org - Talk - View Single Post - Question about Nokia's charger

	Karel Jansens	2009-02-24 , 15:33
	Posts: 3,220 \| Thanked: 326 times \| Joined on Oct 2005 @ "Almost there!" (Monte Christo, Count of)	#10

Originally Posted by jthiemann

Oooh, that's a nice device. However, I don't think you really want to _fully_ charge your internal battery from AA's. The way I understand Li-Ion batteries, they charge fast (and efficiently) up to to 80% or so, but then the remainder is difficult to get in and goes really slowly. I think Nokia has designed it such that in "emergency charger" mode you always stay in the "efficient" region and don't try to charge the battery to the full capacity unless you're on a mains charger.

A proper battery expert can probably tell you that I'm completely wrong and talking out of my a**, but that's the way I understand it. :-)

Ah, but I also have this huge beast of an external LiPol battery, designed for laptops. It has oodles of amp-hours on board and with my regulator I can step down the voltage from 16 to 6 easily and, because it's a switching one, with rather good efficiency (80%+) as well.

Also, the idea is not so much to recharge the tablet, but to give it extra juice running. Like, when I'm way out in the wild, far (like, more than four steps

) from any AC outlet, I could plug the tablet in and let it run off the external battery. Some claim it's even more efficient to run of an external battery with a fully charged device than to recharge the internal battery with external battery power.

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