Invertek SS-30C, Инструкция по установке и эксплуатации

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8-2
may be needed to balance the individual cell voltages.
Other Sealed Batteries:
Automotive and “maintenance-free” batteries are also sealed. However, these are not
discussed here because they have very poor lifetimes in solar cycling applications.
NOTE: Consult the battery manufacturer for the recommended solar charging
settings for the battery being used.
8.2 Flooded Batteries
Flooded (vented) batteries are preferred for larger cycling solar systems.
The advantages of flooded batteries include:
• ability to add water to the cells
• deep cycle capability
• vigorous recharging and equalization
• long operating life
In cycling applications, flooded batteries benefit from vigorous charging and equalization
cycles with significant gassing. Without this gassing, the heavier electrolyte will sink to the
bottom of the cell and lead to stratification. This is especially true with tall cells. Hydrocaps
can be used to limit the gassing water loss.
Note that a 4% mixture of hydrogen in air is explosive if ignited. Make certain the battery
area is well ventilated.
Typical equalization voltages for flooded batteries are from 15.3 volts to 16 volts. However,
a solar system is limited to what the solar array can provide. If the equalization voltage is
too high, the array I-V curve may go over the “knee” and sharply reduce the charging
current.
Lead-Calcium:
Calcium batteries charge at lower voltages (14.2 to 14.4 typically) and have strong
advantages in constant voltage or float applications. Water loss can be only 1/10th of
antimony cells. However, calcium plates are not as suitable for cycling applications.
Lead-Selenium:
These batteries are similar to calcium with low internal losses and very low water
consumption throughout their life. Selenium plates also have poor cycling life.
Lead-Antimony:
Antimony cells are rugged and provide long service life with deep discharge capability.
However, these batteries self-discharge much faster and the selfdischarging increases up to
five times the initial rate as the battery ages. Charging the antimony battery is typically from
14.4V to 15.0V, with a 120% equalization overcharge. While the water loss is low when the
battery is new, it will increase by five times over the life of the battery.
There are also combinations of plate chemistries that offer beneficial tradeoffs. For example,