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Return to Neo FreeRunner Battery.

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Key pages on:
Neo FreeRunner

GTA02 1200 mAh Smart Battery

  • Internally, uses the SANYO 1200mAh cell (note that the Sanyo cell by itself does not have the Coulomb-counter and thus can not be used as a replacement for the Neo FreeRunner battery)
  • Battery Technical information: Detailed Battery Information
  • 1200mAh Smart Battery with Coulomb-counter and protection circuit
  • The Smart Battery keeps track of maximum and current capacity for precise prediction of remaining battery power and time until shutdown, based on actual power dissipation.

For more information, see the GTA01 battery info at Neo1973 Battery

Notes about expected battery life

Battery life is a work in progress. The power saving software is in a very rudimentary state. At the moment 12h is about the most (note though a recent result of at least 21h, mostly in suspend, with multiple short wakeups, on the predecessor device GTA01). A week standby and 6 hours talk, 20 hours mp3 might be attainable when power saving software is complete.

Known Issues

Make sure your battery never discharges completely.

This is an issue because the internal charging circuitry can not be turned on until the FreeRunner has booted, and booting through USB power alone does not work on early A5/6 devices. If your FreeRunner boots to the point of showing something on screen when battery removed and connected to OM-wallcharger, your device isn't affected by this issue.

Depending on NAND bootloader version there might also be a red flashlight on AUX indicating postponed boot while charging battery to a required minimum - just keep your FR hooked up to the charger then until it boots. Or boot to NOR if it doesn't recover during some ten minutes.

What to do if your battery has become completely discharged

See the workarounds here.

More tricks

Q: Does anyone know WHY it don't charge when it is off? My logic says that it is very important to have the option charge the battery when it is flat.

A: I can't give you a simple answer. Charging is controlled by the PCF50633 chip, based on configuration values that are written to it by u-boot, Linux, and userspace programs. Some of these settings are preserved across a power-cycle (the PCF50633 has a small backup battery that's also used to keep the RTC running) so the behavior at startup depends on the software that you used during your last session.

Another complication is that some Freerunners are capable of starting up without a battery while others are not (possibly due to different capacitor values on the internal power rails).

I can give a few hints:

  • The current (Sep. 2nd, 2008) u-boot has a bug that means it will not properly charge from the wall charger. Try a USB cable into a PC instead.
    • Feb. 2009 -- Is the preceding comment still correct? Bug number?
  • Try booting through NOR u-boot instead (hold aux and then power) with both the wall charger or a 500mA USB connection, then try booting Linux.
  • Try to boot into the NAND u-boot menu (hold power and then aux) and then select "power off". This may leave the device in a state were it will charge. Wait 15 minutes and then try to boot Linux.
  • If the device shuts off during one of the above attempts, let it sit for a few minutes and then try that same item once again

Kudos to Mike Montour on the Community mailing list.

Another trick to get a Freerunner with a flat battery up and running would be to press and hold AUX, and then plug in the wall charger. Suggested by joerg, confirmed to work by user azmodie, user jhenkins.

Compatible Replacement Batteries

Other known FreeRunner-compatible batteries include the BL-series (BL-4X, BL-5X) from Nokia, and their third-party equivalents. These may not work to revive a device and may not report charge information. It is probably a good idea to check that your battery is not greater than the stock battery's voltage of 3.7V (the above suggests that 4.5VDC should be fine) unless you know what you are doing.

Battery Model Capacity (mAh) Charge info reported Notes
NOKIA BL-4C 750 no Slightly thinner than original.
NOKIA BL-5B 760/890
NOKIA BL-5C 950 no
NOKIA BL-6C 1070 no
NOKIA BR-6C ? no
Garmin GPS 10x 1100 no

Alien Charging of Battery

Nokia devices (phones and stand-alone chargers) usually will not charge non-Nokia batteries, most likely because they can't be sure they have the correct charging parameters (and of course Nokia isn't interested in supporting use of alien batteries with their phones).

Most after-market or no-name brands of Nokia-compatible chargers don't test the make of the battery, most likely because adding the capability to perform this test would add to the cost of the charger and limit it's universal character (that's not the interest of second source manufacturers).


  • You can use a Nokia or Nokia-compatible BL-4C, BL-5C, or BL-6C in the Neo
  • You can charge the Neo battery in a Nokia-compatible charger that is not Nokia branded
  • You can NOT charge the Neo battery in a Nokia branded phone or charger

Alternatively, the Garmin GPS 10X, a Bluetooth GPS device, uses a compatible battery to the OpenMoko FreeRunner. The device can be used to charge FreeRunner batteries at 100mA, 500mA or 1A over miniUSB (including deep-discharged batteries).

For more information about USB battery chargers that can be used with the Neo FreeRunner see

Main article: USB charger

DIY external battery pack from a Minty case


Charge from a couple of AA batteries: Minty Boost!, report on a Neo FreeRunner application.

Adding the 47k resistor to the minty boost so that the Freerunner fast charges at 1A is a poor idea for a couple reasons, the biggest one being that the minty boost can't supply 1A the max is 600mA. as far as I know, there is no magic resistor to identify a 500mA charger to the Freerunner, it depends on USB host telling it that it can provide 500mA. Second, the ID pin is in the USB micro connector, so you would either need to put a micro connector on your minty boost (with the correct resistor installed) or use a hacked cable.

Even if the Linear Technology step up voltage converter is supposed to be able to do 600mA, the AA cells seem to have a problem with supplying 500mA. They get a little toasty :-). One powerpack built using D cells doesn't seem to have any issues with supplying 500mA.