Alpha Technologies AlphaCell SMU - Manual (Page 11)

11 745-680-B9-001
4.2 Battery Life and Ambient Temperature
The expectant life-span of 10+ years is based on a 25°C ambient temperature. Temperatures
above this optimum increase the rate of plate corrosion and of water loss, which shortens
battery life. For temperatures above 25°C, the relationship between temperature and life-span
is expressed in the following equation:
t
T
= t
25
/ 2 (T-25)/10
Where, t
T
= the actual life span; T= the actual temperature; t
25
= the rated life span at 25°C.
For example, if the actual ambient temperature is 35°C then the expectant life-span is 5
years.
While an ambient temperature slightly below 25°C may help the battery reach its potential life-span, it will
not signifi cantly increase that life-span. In addition, the capacity of the battery and it’s ability to discharge
signifi cantly decrease at temperatures below 5°C. The battery’s optimal operating range is 15°C to 25°C.
NOTE:
A fl oat voltage set higher than specifi ed accelerates the corruption of the grid, shortens the life
of the battery, and increases the risk of thermal runaway. A fl oat voltage set lower than specifi ed
inhibits the battery from holding a charge; this increases sulfation on the plates, decreases the
capacity and shortens the life of the battery.
CAUTION!
4.0 Temperature, Battery Capacity, and Battery Life, continued
5.0 Charging
In order to ensure the battery performs to its potential, it is very important that it is:
•
Float-charged in order to remain in a fully charged condition
• Completely recharged as soon as possible after a discharge, in order to ensure maximum battery
life
• Charged properly
5.1 Floating Charge Voltage and Ambient Temperature
The fl oat charge keeps the battery in
a fully charged state with a small but
constant current which automatically
covers capacity lost from self and other
discharges.
In order to maximize capacity and life
span, the battery’s fl oat voltage must be
set for the ambient temperature range in
which the battery operates.
Ambient Temperature
(°C)
Float Voltage
(Vpc) +/-5%
0–10 2.29
11–15 2.26
16–25 2.23
26–30 2.21
31–35 2.20
36–40 2.19
Table 5-1, Floating Voltage and Temperature