Battery Handbook

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ENERGIZERBATTERYMANUFACTURING
VERSION1.2
Figure11:OverviewofDifferentAirManagementTechniques
high
low
continuous inter mittent
noneorsmall
degreeofair
management
needed,sincecell
capacityis quickly
used
(1‐3months)
highdegreeofairmanagementneeded,
cellhashighairaccessbutisexpectedto
beinservicewithlongper iods of“off”
time(>3months)
DutyCycle
Discharg eRate
throttlingneededto
maximizeservice
time (>3months)
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3.2‐‐ElementsofAirManagement
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Twoelementsofasuccessfulin‐deviceairmanagementsystemareameansforallowingcontrolledair
accesstothebatteryandanairplenumforevenairdistribution.Anairplenumisanairgap,orvolume,
which has access to all of the air  holes on the battery.
The air plenum allows for more even air
distribution over the battery air holes, and it provides a reserve of air immediately available to the
batterytohandlepeakpowerneeds.Controllingairaccesstothebatteryisaccomplishedbycreatingan
access path to the sealed volume of air within
 a device.The air access path is designed to allow a
desired amount of air to flow to the sealed volume of air, which includes the plenum, either
continuously or intermittently.A sealed volume of air can be created by sealing an entire device, a
portionofthedeviceincluding
thebatterycompartment,orjustaplenumabovetheairholesideofthe
battery.Thepowerrequirementsofthedevicedeterminetherateatwhichairisrequiredtoflowtothe
battery.
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Figure 12 illustrates a  simple, cost effective air management solution designed into a device.The
compartmentdoorcontainsano‐ringwhichsealsagainsttheairholesideofthebatterywhenthedoor
isclosed.Theairplenumvolumeisdefined by the compartment doorandthesides  of the
o‐ring.A
slideswitchislocatedinthecompartmentdoortocreateanairaccesspoint.Theslideswitchactsasa
valve which seals the compartment when in the closed position and allows air to flow to the battery
when in the  open position.The slide switch could
be mechanically manipulated by the user or
electronicallycontrolledbythedevice.