On Sun, 18 Aug 2019 15:19:22 +0200 "H. Nikolaus Schaller" <h...@goldelico.com> wrote:
> Hi, > > > Am 17.08.2019 um 20:17 schrieb Andreas Kemnade <andr...@kemnade.info>: > > > > Hi, > > > > I have these kind of replacement "batteries" for the gta04. > > > > https://misc.andi.de1.cc/gta04-batteries-small.jpg > > Nice! > > > > > The right one works, but dimensions are not perfect and feels > > more fragile. The left one worked shortly but then I had no output at > > the terminals. There seems to be some problem between the gta04-side > > battery - terminal and the B- test point. > > > > A picture of the protection circuit is here. > > https://misc.andi.de1.cc/prot-circuit-small.jpg > > > > As I do not have too much spare protection circuits, do you have > > any advice what I should take better care of for the next one? > > The role is to protect the battery cell and not the device powered > by it. > Well, it is just the best mechanical fitness I have. > Well, you can bridge it if you connect an external power supply > and not a battery which does not survive a short-circuit. > > > > > Furthermore with the right one looking at the display is easier > > and I could check current consumption. > > > > The whole thing is interesting because it would allow me to run > > git bisect run with a closed gta04a5. Currently I am using the letux3704 > > for it. > > I remember there was a schematics of the HF08 battery (fuel gauge > and protector) but I did not find it any more. > > Here is an application note by TI and I assume that the HF08 > battery is not very different: > > http://www.ti.com/lit/an/slua456/slua456.pdf > > Most important is that the current sense shunt resistor and the > battery protection FETs are in the - side of the battery. So > if there is a GND connection between the power supply and the > USB shield this effectively bypasses the protection and the > shunt resistor. > Well, I guess the shunt resistor is low compared to that bypass. > Or did I misunderstand the problem and you are looking for better > mechanical design? There you might use three small screws contacting > the battery springs of the GTA04. > yes, it is about the mechanics. I just want to avoid trashing another protector pcb. I do not know the reason why that one got apparently damaged. The microsd adapter is already better than my screw approach. I have checked power consumption of wifi in 2.6.32 (which does not have hdq) using such a screw-based adapter. > Yet another idea would be to design a new "protector PCB" which > only has the three golden battery contacts on one side and some > solder points on the other. Since they are quite small, they > are not expensive to be produced by e.g. aisler.net. > hmm, the contacts are just thing chemical NiAu? Or is hard gold needed here? Regards, Andreas _______________________________________________ Gta04-owner mailing list Gta04-owner@goldelico.com http://lists.goldelico.com/mailman/listinfo.cgi/gta04-owner
