Hach SIGMA 900 - Manual (Page 45)

Page 45
8544apdx_batteries.fm Batteries and Chargers
Appendix B Batteries and Chargers
Lead-Acid (Gel Cell) Batteries
Lead-acid batteries are designed to prevent electrolyte leakage from the
terminals or case. The electrolyte is suspended in a gel, which ensures safe,
efficient operation in any position. Gel cells are classified as “Non-Spillable”
and meet all requirements of the International Air Transport Association.
Maintenance
These lead-acid batteries are maintenance-free.
Note: The use of chargers other
than those provided by
manufacturor for use with these
batteries is not recommended and
may damage the battery or shorten
its life. Charging
The lead-acid cells are designed to be fully charged in 22 to 24 hours using a
lead-acid battery charger. Do not exceed 24 hours or you may damage or
shorten the life of the battery. The charge rate is 500 mA dc.
Temperature
At higher temperatures, the electrical capacity that can be taken out of a
battery increases. At lower temperatures, the electrical capacity that can be
taken out of a battery decreases. However, excessive heat destroys batteries.
Avoid placing batteries near heat sources of any kind. To maximize battery
life, operated the battery at an ambient temperature of 20 °C (70 °F). The
permissible operating temperature range is -15 to 50 °C, however, use in the
5 to 35 °C temperature range is recommended.
Storage
Store lead-acid batteries in a cool, dry place. Their low self-discharge rate and
excellent charging characteristics permit storage for up to one year without
loss of efficiency or appreciable deterioration of battery performance.
At room temperature the self-discharge rate of lead-acid batteries is
approximately 3% of rated capacity per month. The self-discharge rate will
vary as a function of ambient storage temperature.
Figure 1 on page 45 shows the storage self-discharge characteristics of lead-
acid batteries at various ambient temperatures. Table 3 on page 46 shows
recommended storage times for lead-acid batteries.
Figure 1 Battery Discharge Characteristics
Gel Cell Self Discharge Characteristics
Remaining Capacity
Storage Time (months)
0 °C
10 °C
20 °C
30 °C
40 °C
0 3 6 9 12 15 18
0%
20%
40%
60%
80%
100%