Quarterhorse Battery and Resistor Check


This note only applies to older QuarterHorse hardware version 1.3 (fw ver 1.6) units which have the battery soldered to the QH.  Production of this style QuarterHorse stopped around 2016 and was replaced with the current model that features a circuit to draw power from the keep-alive 12V power supplied to the ECM and uses a socketed CR2032 coin cell battery designed to be replaced by the end user.

The battery and circuit on the original QH v1.3 is designed to last 5+ years before needing replacement.  If the BR2330A battery on the QH has become low (<2.0v), the QH will lose its tune memory when the USB is disconnected.  If this has happened, you have two choices:

  1. Order a replacement battery (BR2330A-GAN $3 from us, also available from the usual places), desolder the old one and replace it yourself.  You can expect the new one to last about as long as the last one did.  Be warned: this is not a trivial task unless you have the right tools.  Removing the battery without damaging the circuit board requires care.  If you are not comfortable with circuit board soldering, please do not butcher your QH.
  2. Use the trade in program for End Of Life Hardware.  (for $100, you can trade in your old QH for a brand new unit with the removable battery)

Checking the Battery

To check your QH, mheasure the voltage of the battery (leads are accessible at the bottom of the QH). Record value (good = 2.5v or better, bad = 2.0v or less typically <1v by the time there is a problem).




Very Old QuarterHorse issues – Manufacturing Errors

Many years ago, a number of QH units were shipped with the incorrect resistor in location R4. This can lead to premature battery drain (less than a year). These units were primarily shipped out during 4Q2012 as a result of undetected assembly error (our bad, sorry!).  At this point (2020) we expect that they’ve all been replaced but this stub of information exists as a historical record.  Please note: less than 1% of QuarterHorses ever shipped had this issue before we caught and corrected it.

In order to determine whether your QH is affected by the manufacturing error, measure the resistance (ohms) across R3 and R4.   The correct resistors will give readings of  R3=1.0k and R4=10k (within 5% or so). If R4 instead measures 1.0k, then the unit is affected and R4 needs to be changed to the correct value of 10k. R3 should be fine at 1k on all units.

Measure the resistances across R3 and R4. The ohm readings should be R3=1k, R4=10k.


If the R4 reading is 1k instead of the correct 10k, then contact us for special RMA instuctions.