Temperature
1. Temperature impacts on the battery capacity
BACS’ Battery Capacity display is based on this capacity compensation per degree Celsius and adds this factor into its calculations of Battery Capacity.
2. Temperature influence on battery life span
BACS records the battery temperature over the long-term and the average temperature is shown so that the user knows what the life-span for his or her batteries should be.
3. Temperature influence on Battery self-discharge
BACS shows the trend of the battery voltages over time; also measured is the historical Equalization/Balancing activity in %. If balancing is indicated at 0% but the charger is running, this would indicate either that the battery breaker may be open and the self-discharge is draining the battery – OR – the temperature is too high so that the self-discharge is greater than the current from the charger, which has to be altered to compensate the behavior of the temperature increase or aging effect of the batteries.
4. Temperature influence on Battery charge current
At a given constant voltage, the float current passing through a fully charged stationary battery increases progressively with increasing battery temperature.
BACS shows this increasing current and balances this out within the limitations of the system. Typically, this is enough to avoid battery damages because the UPS or charger automatically decreases the charge voltage (and the current) if the external sensor reads higher temperatures.
5. Influence of ripple currents on battery temperature
BACS monitors and indicates AC and DC ripple currents, allowing for corrective action before such an effect causes an increase in battery temperature.
6. Temperature differences due to a poor design of a battery installation can cause battery faults
BACS is able to balance the voltages within the string, whether the voltage differences come from the poor layout or from chemical differences within the batteries. This ensures that performance reduction owing to temperature differences due to poor design in the battery layout is otherwise negated.
7. High temperature differences for a time period > 24h can cause a thermal runaway
BACS: If the charger is setup correctly and BACS can balance the voltage differences due to thermal or electrical differences, the risk of such a thermal runaway under float conditions can be dramatically reduced or avoided entirely.
8. High Temperature
BACS cannot prevent overheating of batteries due to room ventilation issues, but BACS can warn the user about such conditions and, if connected to the appropriate automation interfaces (GXRAUX), it can automatically switch on Air conditioning or trigger to open windows, fans, etc. to solve the situation.
9. Real Cooling Demand
BACS: The cooling demand is determined by the difference recorded by BACS; it generally increases with age due to the increased current consumption during trickle charging and thus indicates an increasing risk of thermal runaway.