From our long experience of providing
industrial battery charger solutions to our customers and partners, we have seen that there are some
basic questions that are always asked. Here we are sharing some of the common questions and their answers regarding the industrial battery charger for your convenience.
How do you know when the charger should operate in float or equalize mode?
Regardless of the intended purpose of increasing the charger’s voltage there needs to be a way to start and end charging at voltage higher than float.
The most common control methods are shown below.
Control method: Manual switch
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Advantage: Simple, cheap
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Disadvantage: High risk of forgetting unit is operating at elevated charging voltage
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Comment: Not recommended
Control method: Manually initiated timer
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Advantage: Simple, and automatically terminates charge
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Disadvantage: Requires user intervention
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Comment: No way to know when battery would benefit from elevated voltage charge. No way to know what the right time setting is.
Control method: Automatically initiated timer
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Advantage: Suited for remote sites where users do not visit frequently
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Disadvantage: Time must be pre-programmed.
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Comment: The correct pre-programmed time cannot be predicted since depth of discharge is likely to vary
Control method: Automatic initiation with battery-determined end
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Advantage: Termination of elevated charge voltage is based on battery needs, not a program
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Disadvantage: High continuous current can trick system into staying at elevated voltage too long
When is battery temperature compensation needed? How important is it?
It is well known that all
storage batteries –
vented or VRLA lead acid or
nickel cadmium – require different charging voltage at different temperatures. When cold, the battery requires higher than normal charge voltage in order to deliver maximum possible performance. When warm, charging voltage must be reduced to prevent overcharging and consequent loss of electrolyte.
When the battery is located in a well-controlled environment temperature compensation adds little value. In contrast, temperature compensation is absolutely essential when batteries are located in
outdoor cabinets or other areas subject to extremes of temperature. These facts illustrate the value of temperature compensation:
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When a battery that is 90 degrees F in temperature is charged at the correct voltage for 50 degrees F it will be boiled dry in three months.
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When a battery 20 degrees F is charged at the correct voltage for 50 degrees F it will fail to charge – and thus fail to deliver its specified performance.
Using a charger equipped with automatic temperature compensation can prevent both of these problems.
I am thinking about disabling the temperature compensation feature because the charger and battery are not in the same location, and I am worried about overcharging the battery.
Temperature compensation should only be disabled if the batteries can always be guaranteed to be at room temperature (25°C, or 77°F).
Remote temperature sensing (RTS) is the correct way to provide temperature compensated charging where battery and charger are in different ambient. It is always preferable to both non-compensated and locally compensated charging. Using a sensor attached directly to the battery eliminates all variables of charger temperature and different room temperatures. There is no downside to using RTS. Compared with either disabled or in-charger temperature compensation, RTS will absolutely, positively increase battery performance to the maximum possible. Regardless of conditions, RTS causes the charger to deliver the exact voltage needed by the battery.
EverExceed made a provision to disable temperature compensation mainly for customer acceptance testing – to demonstrate that the voltage setting agrees with the actual output voltage. This can be difficult to determine in a temperature compensated charger.
EverExceed designed its RTS system so that if the remote sensor is damage or becomes disconnected the charger reverts to non-compensated operation. This change is indicated on the charger front panel.
Why do nickel cadmium batteries need to be “boost” charged?
Nickel cadmium batteries offer the highest reliability of any battery, and are more resistant to mechanical and environmental abuse than lead-acid batteries. They do, however, need special charging in order to deliver maximum performance.
If a nickel cadmium battery is charged only at the float rate it will typically deliver only about 70% of its rated capacity. This is a more serious problem for high rate applications, such as engine starting, where even small reductions in capacity have a significant impact on performance.
The most effective way to insure full capacity is available in a nickel cadmium battery is to periodically charge it at an elevated voltage. This can be initiated either manually or automatically, depending on the charger. Automatic equalization is easier to use, and reduces the risk of forgetting to switch back to float voltage.
Conclusion:
