3 This is a simple but effective, dual-rate, standalone charger for Lithium
4 Polymer batteries. It supports tho different charge rates selectable with
5 a swtich, of approximately 100mA and 500mA. The 500mA rate is good for
6 batteries of 400 mAh and higher including the 900mAh cells sold with
7 [TeleMetrum](../TeleMetrum) starter kits, while the 100mA rate is more
8 appropriate for the 110mAh cells often used with [TeleMini](../TeleMini). A
9 standalone charger is essential for use with TeleMini since it does not
10 have on-board charging capability.
16 * Micro USB connector for power input
17 * 2mm JST-style connector for battery
20 * green when charge complete
21 * both on, or "yellow", when battery is disconnected or bad
22 * 1.0 x 0.4 inch board
24 ### Developer View ###
27 * [Microchip MCP73831](http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en024903) Li-ion battery charger chip
29 * [gEDA](http://www.gpleda.org/) for schematic capture and PCB layout
31 * The hardware is licensed under the [TAPR](http://www.tapr.org) [Open Hardware License](http://www.tapr.org/ohl.html)
35 The design files can be found on [git.gag.com](http://git.gag.com) in the
36 project [hw/lipocharger](http://git.gag.com/?p=hw/lipocharger;a=summary).
40 After some iteration, we have settled on a design that meets our needs.
41 Boards will be available for sale soon.