QuarterHorse Battery Life

We get asked, “How long will the battery on the QuarterHorse last?”

Unfortunately, we can’t give you a straight answer to this.  It’s not because we’re trying to be difficult – it’s because there are a LOT of variables.

Some things that impact battery life:

  • How much the QH sits vs. the car runs.  The battery on the QH is only used when the key is turned off.  If you drive the car more, the battery will last longer.
  • The temperature that the unit is stored at has a huge impact on battery chemistry.  Self-discharge increases dramatically with storage temperature.
  • The temperature that the battery operates at has a huge effect on its performance.  Lower temperatures decrease the useful life of the battery.
  • Extremely high temperatures (>60C) contribute to extremely rapid death.
  • Batteries discharge while being stored.  We try to buy the freshest stock possible.  We do production runs annually to minimize the time that batteries sit on a shelf prior to being deployed in the field.
  • The conductivity of anti-static bags (like what we use to ship the units) is such that sitting on a shelf prior to sale can adversely affect the battery life.  A technote from Panasonic recently highlighted this. (we’ve altered our storage methods to combat this)
  • There is a decent amount of variation among individual batteries.

The “show car” in a cold climate (i.e. comes out a few times a year) that stays in an unheated garage is pretty much the worse case imaginable.

For a healthy QuarterHorse, we’ve come up with a worst case figure of about 2.5 years and a best case figure of about ten years for battery life.

The chips (F3, F8) that we sell use non-volatile Flash chips that (at least on paper) have guaranteed memory retention of at least 20 years.

While many people think of the QH as a chip and leave it in their vehicle full time, the QH was never intended to be a permanently-installed piece of gear.  It was intended as an emulator, a tuning tool, something to be tethered to a laptop for use.  In cases where the vehicle will no longer run on a factory computer, a dead battery on an emulator will strand you unless you have a laptop handy to re-load the tune.  Like all of our other emulator products, we recommend that a chip be used for long-term operation.