Ibex Battery Systems

Operation Manual

Mounting The output voltage of the charger is temperature compensated to match the requirements of a sealed lead-acid battery. The charger and battery should be mounted in the same enclosure so they experience the same ambient temperature.

Ambient temperature differences between the charger and battery have little effect during battery charging (bulk mode or absorption mode). If, however, the temperature difference is greater than 10C during float charging, the charger's output voltage may no longer be correct for long-term battery charge maintenance.

The charger is designed to be mounted inside a chassis or equipment rack on four 3/16" (minimum height) standoffs.

Because the charger is a switch-mode power supply, it generates much less heat than a conventional linear supply. However, the power transformer can get warm at full load, so some ventilation is still needed if the enclosure is small.

The unit supplies up-to the full specified output current to +65C. Above +65C, the available output current is gradually reduced to the +85C specification. If the board's ambient temperature rises above +85C, the charger shuts down. It automatically restarts when the temperature falls below +85C.

Enhanced 3-Mode Charging This unit automatically charges the battery in three modes (bulk, absorption, and float charging). Because the charger is controlled by a microprocessor, it has the "intelligence" to determine whether or not a load is connected across the battery as it is being charged and to compute the ideal charging time for each charging mode. Because of this, the charger can be used to charge stand-alone batteries or as a combination charger/power supply. In either application, the charger properly charges the battery, using each of the three charging modes, with no danger of the charger locking itself into the absorption mode.

Mode 1 - Bulk Mode The charger is in current-limit and delivers its maximum rated current (1.0A to 2.0A) to the battery. The "LED" signal is flashing. It is in this mode that the battery receives most of its recharge. When the battery voltage rises to approximately 14.7V, the battery is at a 75% to 90% recharged level and the charger switches to absorption mode.

Mode 2 - Absorption Mode The charger is in a constant-voltage mode delivering approximately 14.7V to the battery. The "LED" signal remains flashing. It is in this mode that the battery is brought to a 100% recharged level. The charger's microprocessor calculates how long to keep the charger at the elevated absorption mode voltage. It doesn't matter if a load is across the battery during charging. The charger compensates for any current stolen by the load and completely recharges the battery.

When the battery is at a 100% recharged level, the "LED" signal becomes steady. However, the charger may remain at an elevated voltage for several more hours before switching to the float mode voltage. This helps to equalize the charge in all of the battery's cells.

Mode 3 - Float Mode The charger is in constant-voltage mode at a lower voltage than in absorption mode (approx. 13.8V) This allows the battery to draw just enough current to make up for its internal leakage current. When the charger is in this mode, the battery may remain connected to the charger for all of the battery's service life with no damage to the battery.

If the battery is removed while being charged (the "LED" signal flashing), the charger attempts to continue charging the (now-disconnected) battery. It automatically resets itself to the float voltage after several hours. If the battery (or a different battery) is connected to the charger during this time, the charger re-calibrates its charging times to properly charge whatever battery is connected to it.

Output Connector The output connector has four pins with the following connections. Please see the mechanical data sheet for connector specifics.

low temp sla lead acid battery charger
LED The charger has a signal available to power a customer-supplied LED or to interface to TTL circuits. The signal is a 0V sink or +5V source in series with 470 ohms. When the battery is fully charged, the signal is held high (LED is on). When a battery is being charged, the signal flashes - 0.5 second on, 0.5 second off. If the battery is reverse connected to the charger output, or if the line power fails, the signal is off. If using an LED, connect the LED's "+" lead (anode) to the "LED" pin and the "-" lead (cathode) to the charger's "-BAT" pin.

TSENSE This pin is no longer used. Do not connect to it.

+BAT This is the charger's current output pin and should be connected to the "+" terminal of the battery and, optionally, to a load. When off, the charger draws very little leakage current from the battery (less than 0.5mA) and so may be permanently connected. The load does not have to be disconnected when charging the battery (provided it doesn't consume all of the current). The charger detects when a load is across the battery and adjusts its charging algorithm to properly charge the battery.

The charger is not damaged by a short circuit at the battery terminals. However, in the event of a short circuit, even though the charger is not damaged, the battery may deliver a very large current that may melt wires or cause a fire. The battery should be fused close to one of its terminals - PolyFuses work well. Size the battery wires and the fuse according to the current draw of the application.

-BAT Connect this pin to the battery's "-" terminal. Also, use this pin as a return for the LED signal.

Input Power The six pin input power connector must be jumpered as shown below. It is important that both transformer primary windings be used. Do not use the charger with just one winding connected.

high temp sla lead acid battery charger
The S12-1.0/115AC charger is designed to be powered from a 115/230VAC line at 50 or 60Hz. The line input should be externally fused at 1A (115VAC) or 0.5A (230VAC).

Recommended Battery Size   6Ah or larger

Note that some batteries can not be charged at a C/3 rate (this corresponds to a 6Ah battery charged at 2.0A). Check with the battery manufacturer. It may be necessary to use a larger battery. Also, at cold temperatures, the charger's output current can reach 3.0A. Because a battery's maximum charging current value is specified to prevent thermal damage (which won't happen at cold temperatures), a battery need only be rated for the charger's maximum current at room temperature (which is 2.0A).