Product # 6429B
Backpack User Guide
Page 4 of 7
2. Inside the Power Pack you will find two Battery Placeholders - one at each end of the Power Pack. These are for
use with eight Alkaline Batteries. If you plan to use ten NiMH (Nickel Metal Hydride) Rechargeable Batteries,
remove the two Battery Placeholders and keep them for possible later use.
Note: Alkaline batteries have a voltage of 1.5 Volts per cell, so only eight of them in series are required to
supply 12 Volts to operate the pump. Use of the two Battery Placeholders is required in the two remaining
open slots in the Power Pack in order to complete the circuit. The Battery Placeholders can go in any of the
open slots. NiMH Rechargeable Batteries have a voltage of 1.2 Volts per cell, so ten of them in series are
required to supply 12 Volts to operate the pump.
3. Replace the dead batteries with new ones, taking note of their alternating positive/negative orientations (the flat
end of each cell goes against the spring).
4. Close the Power Pack Lid and wrap the three Velcro Closures over the Lid to hold it tightly closed.
5. Reconnect the Power Connector by pushing it all the way into the Socket of the Power Pack until the Latch
engages, locking it in place. Replace the Power Pack back into the Battery Pouch of the Backpack and close the
Flap securely.
When storing or transporting your Backpack, slide the Power Switch Guard UP to prevent the Power
Switch from accidentally being turned on.
USING AN EXTERNAL POWER SOURCE:
The Backpack can be powered from an external 12V DC power source using the optional External Power Cord.
This is especially handy when the Backpack is used in or on a vehicle, eliminating the need for the Power Pack. To
facilitate easy connection/disconnection of the External Power Cord, the red & black Power Wire inside the Battery
Pouch can be routed externally as follows:
1. Insert the white plastic Socket on the end of the External Power Cord into the small opening in the bottom seam
of Battery Pouch (located about 1 inch to the right of the lower left corner).
2. Feed the External Power Cord into the opening until the Socket protrudes out the top of the Pouch, then plug
the white Connector on the end of the red & black Power Wire into the Socket.
3. Pull the External Power Cord back out of the opening until both the Connector and Socket come out. Continue
pulling until the entire length (approximately 14 inches) of the red & black Power Wire is exposed, and then
unplug the External Power Cord.
4. The Connector on the red & black Power Wire can now be passed under and through the Velcro Wrap on the
Backpack’s two Hoses so the Connector is retained near the Quick-Connect Fittings on the Hoses, keeping it
within easy reach when connecting the External Power Cord while wearing the Backpack.
DRAINING WATER BEFORE REFILLING THE RESERVOIR:
It's not necessary to turn the Backpack upside down to drain any of the water before refilling. An alternate method
is to simply press in on the round spring-loaded tip of the Male Connector at the end of the backpack’s Outlet Hose
with just the tip of your finger or fingernail to let the water stream out, as was shown in Step 5 of FILL THE
RESERVOIR. This can be accomplished even more quickly by turning the Power Switch ON at the same time.
Answers to Some Questions You May Have:
How long will the ice last?
The ice can last as long as four hours or more, or can melt in as little as 90 minutes in extreme cases. The actual
duration depends on many factors which can be divided into two groups: How much "cold" you start with and how
rapidly heat is absorbed.
It takes more heat to melt a pound of ice just removed from a deep freezer than a pound of ice that has been
sitting out and is beginning to melt, thus the colder the ice you start with, the better. When you add water to that
ice (which is necessary for circulation through the pump and vest), it "warms up" the ice, so adding only a minimal
amount of the coldest water possible (ice water) is best.
More body heat is generated by a person rigorously exercising than at rest. More heat will be absorbed when the
vest is worn tightly against bare skin as compared to loosely over a shirt. In addition, more heat is absorbed from
the surrounding environment when the ambient temperature is high and there is nothing worn over the vest. This
is why we recommend wearing at least a lightweight windbreaker-type jacket over the vest to minimize loss of
cold to the atmosphere.
