> Am 14.11.2017 um 18:29 schrieb Xavi Drudis Ferran <xdru...@tinet.cat>: > > El Tue, Nov 14, 2017 at 10:20:12AM -0700, j deia: >> you can get universal battery chargers in Ebay, they are spring loaded and >> have charge pins that can be moved side to side to accommodate most cell >> phone batteries >> > > But are they safe for those batteries ? Did you try them? > > I half remember most smartphone batteries include a charger chip > and GTA04 batteries do not (the chip is in the phone and should be > in the charger). > > But maybe I got it wrong, I remember having read about it loooong ago.
There is a bq27000 fuel gauge in the GTA0x batteries - it remembers the fuel level even if the battery is taken out. There must be some charger which which knows how to safely charge LiIon batteries until they are full. The GTA04 has a twl4030/tps65950 with some optional software control. For the separate charger I want to use the bq24040. Both (twl4030/b24040) need some external power, usually 5V from an USB wall charger. Safely building such a device is beyond my plans... So the idea is to use existing Mini/Micro-USB-power supplies. BTW: I'd prefer to use USB sockets because there you can assume 5V and a specific polarity. Barrel connectors can be reversed or have 12V or even 19V which will damage the bq24040. For the daisy-chaining I have found a plug for µUSB that can be soldered to the opposite edge of the socket so they should fit. I have ordered some sample and then we will see... BR, Nikolaus _______________________________________________ Community mailing list Community@tinkerphones.org http://lists.goldelico.com/mailman/listinfo.cgi/community http://www.tinkerphones.org