rated for 750 mA all-fire current, 5 x 750 = 3750 mA, so that 300 mAH/20C battery that can put
out 6,000 mA would be just fine.
Regardless of what kind of batteries you choose, charge or swap out your batteries before
every session, and check the voltage with a digital voltmeter before every flight. The
votlage/percentage meter on the Status page is a guideline to tell you about how much battery
you have left, but it’s not as accurate as a decent DVM. You don’t want to spend all the time to
find the “perfect” battery combination for your 54mm minimum-diameter Mach-buster only to
realize after you dig it out of the ground after lawn-staking it that you forgot to charge the
battery.
Now, you may be wondering what happens if your igniter fires and causes a “dead short”.
We’ve seen that happen a few times, interestingly enough with very low current ematches,
probably because their wires are very close together so any mechanical thrashing about after
firing can cause the wires to touch.
Unlike deployment controllers that use FET’s on the output, the “smart” drivers in the Quasar
provide current-limiting to the output igniters, generally around 10A. Especially with a LiPo,
this helps prevent dead-shorts from damaging the battery and/or the output drivers. The drivers
will also shut off the outputs if the input voltage drops below 5V, which prevents the dreaded
“brownout” (which causes the altimeter to reset when the input voltage drops too low). Unlike
other altimeters, the Quasar doesn’t have a large “brownout capacitor” on the power… it doesn’t
need one. We’ve intentionally dead-shorted the Quasar’s outputs in testing, with no harm to the
Quasar at all.
If you’re using an ematch, you only need to set the deployment on-time to ONE second… if they
don’t fire in a few hundred milliseconds they probably won’t fire at all. If you’re using a hot-
wire (for example, to cut a cable tie or nylon fishing line) you’ll need to experiment with the on-
time. You’re going to want to do this on the ground, of course… flight-time is NOT for
experimenting with your deployment parameters!
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