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Lithium batteries

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DavidA:
I had another look at this tablet.

And I had actually made a mistake.

There are, as I mentioned, three connections from the battery to the PC board.

So I clipped them off close to the PC board (leaving enough for any future 'modifications) and connected the red and the black to a parallel pair of cells I recovered from one of my old lap top batteries.

So I have, when fully charged, 4.2 Volt at some as unknown Amp Hour capacity. I'm doing a complete discharge/recharge on a similar 2 cell pack that will hopefully give me the capacity.

Anyway, it works nicely. I haven't let it get down to minimum voltage yet (3.3 Volt) but it looks promising and certainlt runs for longer than the faulty original.

At the top I mentioned I made a mistake.

This effects the recharging.  At the moment I have to disconnect the  cells and put them on charge. No big deal as I have spare cells and I fit them with plug and sockets to make it an easy job.

But closer examination of the original (flat pack) battery I removed, complete with it's charge controller (Where all three wires from the PC board terminate) shows that there are only two connections from the charge controller to the actual battery. A Pos' and a Neg'.

So all I have to do is disconnect the faulty cell(s) from the charge controller at these points, then connect my new cells to it at the same points.

I can then re-connect the three charge controller wires to the PC board and I believe I can charge as normal via the mini USB connector. I have a 'charge Doctor' volt/current monitor that shows what the battery is drawing when charging.

Dave.

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