AA Power board¶
The AA Power board is a small board which can generate a stable 3.3V from a single AA battery (Alkaline or NiMh), sufficient to power a JeeNode, for example:
The board uses an ultra low-drain LTC3525 boost regulator chip which draws only 7.. 30 µA in idle mode (depends on input voltage). The input can range from 1.0V to 5.5V, so this can also be used with 2x or 3x AA battery packs (even 4, if NiMh), and it will continue to work when hooked up to a 5V power supply in a lower efficiency “burst” mode. The regulator continues to operate with input voltage fading to less than 0.5V - squeezing the last bit of energy from the battery.
The board was specifically designed for use with a JeeNode with several different mounting options, but can be used with anything that needs 3.3V. An AA or AAA cell can be mounted directly onto the board. The maximum output current is 60..150 mA, depending on input voltage.
Caution: Check the battery clips are clear of the target board parts/tracks when plugged ’inverted’.
There is one solder jumper, which is left open in most cases. When used, it selects which power source feeds the PWR pin :
- 3V (the output of boost regulator) * BAT (direct from the on-board battery)
The BAT+ choice is useful if you want to track the actual battery voltage - on the connected JeeNode, just link PWR to an ADC pin (see the Weblog link below).
Dimensions: 21.1 x 68 mm
CadSoft EAGLE design files: see below.
How to Get It¶
The JeeLabs Shop
N.B. There is a 5V version of this board available at Modern Device
Identical circuit, different part number for the LTC3525.
Related Weblog Posts¶
- 2010-09-06 - Running off a single AA battery
- 2010-09-16 - Meet the AA Power board
- 2010-09-17 - Long live the AA battery!
- 2010-09-18 - AA mounting options
- 2010-09-19 - AA power options
- 2010-09-20 - Lots of AA’s
- 2011-06-20 - AA boost ripple
- 2011-06-21 - MCP1702 current draw
- 2013-05-15 - What if we want to know the battery state