Many battery options present themselves. Remember, your Z-11Pro will work well with as little
as 8 volts. Let's assume that you'll make 20 tunes per day: 15 memory tunes and 5 full tunes.
That amounts to 2 mAh per day
. Here are some estimates of battery life for various
combinations of cells:
Qty
Type
mAh Days
Notes
Three
AA Lithium
2100
1050 (these are 3.6 volts each)
Eight
AAA NiMH
850
425
Eight
AAA Alkaline 1150 575
Eight
AA NiMH
2000 1000
Eight
AA Alkaline
2850 1425 (almost 4 years!)
Note that these estimates do not account for self-discharge in NiMH batteries. Choose NiMH for
more frequent or heavy use, Alkaline or Lithium for long shelf life. Lithium batteries are more
expensive, but are quite a bit lighter than Alkalines of the same size, and you only need three 3.6
volt Lithium cells instead of eight Alkalines. This makes them an attractive option for portable
operation, adding minimal weight.
Also note that while a single 9V battery is within the voltage specification, it does not produce
enough current to properly power a Z-11Pro.
Suitable battery holders are readily available. Radio Shack (
) sells holders
for 4 and 8 cells. Mouser (
) and Digikey (
3, 4, 6 or 8 cells.
To install a battery or battery pack inside, disconnect your Z-11Pro. Open the case by removing
the four screws (two on each side) and carefully lifting the top clear. You'll find room inside for
the battery or battery pack on top of the relays; use double-sided foam tape to attach it there.
There are two terminals on the Printed Circuit board for battery power. They are round lands with
holes, immediately behind the DC power jack. The one directly behind the jack is for the Positive
lead from the battery connector or holder (usually Red), the one offset slightly toward the center
of the circuit board is for the Negative lead (usually Black; see the detail inset in the photo
below). Carefully solder the leads into place, taking care to avoid solder "bridges" to other parts
of the PC board. If you are using AA or AAA batteries in a holder, put a length of tape over them
to keep them securely in their holder.
2
The tuner draws 250 mA average while tuning and virtually no current while idle. Memory tunes take 0.1
seconds, full tunes 3 seconds on average. Your battery life will depend on how you operate, how often you
tune, and whether you use full or memory tuning.
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