Alpha Technologies AlphaCell SMU-HR - Manual (Page 9)

9 745-680-B2-002, Rev. B
1.3 Operating Conditions
Because SMU-HR batteries, which are valve regulated and virtually sealed, do not give off
perceptible amounts of gas under normal operating conditions, they can be installed in the
same environment where people live and work.
Acceptable ambient operating temperature: -40ºF to 131ºF (-40ºC to 55ºC) •
Ideal ambient operating temperature: 68ºF to 77ºF (20ºC to 25ºC) •
Ambient humidity: ≤ 95% •
Operating room or area: ventilated and not fully sealed •
1.4 Capacity
Battery capacity is rated in Ampere hours (Ah) and is the quantity of electricity that can be
supplied during discharge (See Table 1-1).
The actual capacity is related to the utilization ratio of the active positive and negative
materials within the battery. The utilization ratio is influenced by the depth of discharge, the
structure of the battery, and the manufacturing technology. During normal usage, the factors
that influence the actual capacity are discharge rate, depth of discharge, end voltage, and
temperature.
The higher the discharge rate, the lower the available capacity. •
As batteries get colder, the available capacity is reduced. This is related to the kinetics of •
the electrochemical reactions and the resistivity of the electrolyte (See Fig. 1-1).
NOTE:
Although the battery can be operated at temperatures below 5ºF (-15ºC), the capacity and ability to
discharge will be dramatically decreased. Similarly, temperatures approaching 122ºF (50ºC) will increase
water loss and corrosion of the plates, resulting in a shorter battery life.
1.0 Introduction, continued
Fig. 1-1, Available Capacity vs. Ambient Temperature
Capacity (%)
Ambient Temperature (ºC)
-40 -30 -20 -10 0 10 20 30 40 50 60
0
20
40
60
80
100