NIMH battery gauge


Submitted by: Volhout Project Website: N/A


In remote controlled airplanes, a 4.8V (4 cel) battery is used to power electronics. To prevent flying an airplane with an empty battery, this battery condition checker is developed. It is based on a PICAXE 08M2, powered from the NIMH battery, measuring the voltage with the A/D converter. The value is compared to set levels in software (4.2V / 4.8V / 5V / 5.2V) and drives 4 LED's. Since the 08M2 is short on IO pins, the LED's are multiplexed. The software cycles fast enough to detect glitches (if servo's draw much current, and the battery is older (higher internal resistance). Especially these glitches can cause a hard reset of the RC receiver, causing loss of control for up to 2 seconds. (2 seconds is lethal for an RC airplane).
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  • Posted by HeinzB

    Hi Volhout,

    looks good and it seams I could use it my own.

    But the picture is to little to see your logic. Can you share the bigger picture and share your code.

    Regards Heinz

  • Posted by Volhout

    Dear HeinzB

    Saw your comment just today. Will get to it this week. Sorry for the delay. Will have to find out how to post code on this site.

  • Posted by Volhout

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