Ibex Battery Systems

General Description



General Description


Operation Manual


12V Chargers

General Description: This microprocessor-controlled, enhanced 3 mode, bare-board charger may be used as a combination charger and switching power supply. A charger status signal is available that may be interfaced to TTL circuitry or can power a front-panel LED.

The output voltage is temperature-compensated to prevent over-charging at high temperatures and under-charging at low temperatures and may be field adjusted.

The charger withstands a continuous output short circuit or reverse battery connection. Conservative ratings and 105C rated filter capacitors allow a long service life in industrial environments. The unit may be operated in an ambient temperature of -40C to +65C at full output current or to +85C at reduced output current and can be powered from either 115 or 230VAC (jumper selected). Above +65C the unit automatically reduces its maximum output current. Above +85C, the unit automatically shuts down but restarts when the board temperature goes back below +85C.

Combination Charger/Power Supply This unit is designed to be permanently connected to the battery and the application load. When AC mains power is available, the charger will charge and maintain the battery while also powering the application load. When the mains power fails, the battery continues to power the load with no service interruption. The current draw by the load does not interfere with the operation of the charger.

Enhanced 3-Mode Charging: The 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 ( App note 6, "Why some chargers fry batteries" ).

Mode 1 - Bulk Mode: The charger initially is in current-limit and delivers its maximum rated current to the battery. 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 automatically switches to absorption mode.

Mode 2 - Absorption Mode: The charger is now in a constant-voltage mode delivering approximately 14.7V to the battery. The charger's microprocessor calculates how long to keep the charger at the elevated absorption mode voltage. It doesn't matter whether a load is across the battery during charging. The charger completely recharges the battery by altering its charging schedule to compensate for any current stolen by the load. When the charger determines that the battery is 100% recharged, the charger automatically switches to float mode.

Mode 3 - Float Mode: This is for battery charge maintenance. The charger is now in a 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. The battery may remain connected to the charger for all of the battery's service life with no damage to the battery.

The charger remains in float mode, maintaining a 100% state of charge in the battery, until the charger is needed to perform another charging cycle. If this happens, the chargers automatically switches back to bulk mode and the entire 3-mode charging cycle repeats.

Switching Power Supply: Because the unit uses a switching power supply, the heat generated is greatly reduced and, without bulky heatsinks, the board height is lower. Some enclosure ventilation is still needed, but much less than with a linear supply.