Personal Ambulatory Oxygen System
Provider Technical Manual
20771733 D 11
Figure 6: Battery Pack Status Gauge
While the eQuinox Battery Pack allows the concentrator to operate at
its full range of capabilities, the primary purpose of the Battery Pack
is to allow a patient to ambulate while they are moving between
stationary power sources. The eQuinox’s Battery Pack, like all lithium
ion batteries, is susceptible to permanent damage from excessive heat.
Exposure to excessive heat may significantly shorten the service life of
the Battery Pack.
Each Battery Pack contains multiple temperature sensors to monitor
battery cell temperature. The amount of heat the Battery Pack can
safely endure varies depending on how the Battery Pack is being
used. During discharge, the eQuinox software will alarm when internal
battery cell temperature exceeds 60°C, and will shut the system down
if internal battery cell temperature exceeds 75°C. While the Battery Pack
is charging, software will interrupt charger operation when the internal
battery temperature exceeds 45°C or temperature is less than 0°C . In
both of these cases, when internal battery cell temperature falls within
these limits, the eQuinox will resume normal operation. Operation near
these temperature limits will not damage the Battery Pack, but are in
place to ensure that the service life of the Battery Pack is preserved.
Heat in the Battery Pack is generated during discharge, and can also
be the result of operating the eQuinox in high ambient temperatures.
The amount of internally generated heat varies with the flow setting –
higher flows induce greater Battery Pack heating. While high ambient
temperatures are typically the result of operation on a hot day, running
the eQuinox with inadequate ventilation can also add additional
heat. Always ensure that the eQuinox is operated in a well-ventilated
space, the air intake filter is clean, and intake and exhaust vents are
unobstructed.
Charging Algorithm
The charging algorithm is performed by the Power Manager software
and involves three basic decisions:
1. When to start charging
2. How fast to charge
3. When to stop charging
Charging begins when Battery Pack voltage falls below 90% charge.
The charging current is limited by the charger capability and the rated
capacity of the Battery Pack. Under certain conditions, the eQuinox
may not have enough external power available to charge the batteries
at the full rate. In this case, the charging rate will be limited to the
available power.
The software will only charge when the Battery Pack temperature is at
or below 45°C. The software will always run the cooling fan whenever
the charger is enabled. The Battery Pack charger is disabled and the
cooling fan is set to maximum whenever the Battery Pack temperature
exceeds 45°C. The Battery Pack charger is disabled when temperature is
less than 0°C.
All lithium ion batteries self-discharge at very low rates when not
in use. eQuinox Battery Packs are shipped from SeQual in a partially
charged state (nominally 30%). When stored in a cool, dry location, the
Battery Pack can sit unused for up to 12 months without appreciable
self-discharge occurring. Nevertheless, CAIRE recommends a first in,
first out rotation of Battery Pack inventory for maximum Battery Pack
service life.
