[Lenny400] Replacement batteries

[Dr. H. Nikolaus Schaller]

Hi,

Am 06.04.2015 um 16:18 schrieb Daniel Glöckner <daniel-gl at gmx.net>:

> On Mon, Apr 06, 2015 at 02:23:28PM +0200, David Boddie wrote:
>> What constraints on the battery, other than 7.4V, the size

In my experience the dimensions are the main constraint if you want comparable
capacity (2100 mAh).

I did not yet find any battery for replacement and the originals are nowhere obtainable
any more (not even on strange chinese web pages).

Pointers are welcome. We can then even add them to the shop.

>> and maybe also
>> the capacity do I need to be aware of?

Please think about short circuit/high temperature protection.

>> I'm mostly thinking about issues
>> related to the recharging circuit in the minibook itself.
> 
> The capacity is not a constraint.
> 
> The Letux 400 uses a TI BQ2057W for charging. It will stop charging
> when the battery reaches 8.4 V:
> http://www.ti.com/product/bq2057w/description
> 
> The sense resistor is 0.2 Ohm and it uses high side sensing, so the
> battery must sustain being charged with 0.7 A.
> 
> Both R_T1 and R_T2 (see BQ2057 datasheet) are 1.5 kOhm resistors,
> if you want to add a thermal protection circuit to the battery.


BR,
Nikolaus