Samlex 24V 40A 2-Bank 3-Stage Battery Charger

The Samlex SEC-2440UL is a fully automatic charger designed for two 24V lead-acid battery banks in marine, RV, communications, backup-power, and mobile applications. Its switch-mode design keeps the charger relatively light and efficient while allowing both banks to charge from the same unit without a separate isolator. The normal charging algorithm uses bulk, absorption, and float stages to bring batteries back to capacity while limiting unnecessary stress after charging is complete. A DIP-switch setting can change the charging behavior when the batteries remain connected to an active DC load.

The charger can also operate as a DC power supply or as part of a battery-backed DC UPS arrangement, which makes it useful beyond routine battery maintenance. A half-power mode reduces maximum charging current for smaller battery banks that do not need the full output of the charger. Built-in voltmeter and ammeter functions give the operator direct feedback on charging conditions without requiring separate instruments. Fan speed responds to output current so cooling demand follows the actual work the charger is doing.

Protection is provided for short circuits, overload, reverse battery connection, and excessive temperature. The included temperature sensor helps compensate for large battery-temperature changes that can otherwise lead to undercharging or overcharging. The charger measures roughly 15 x 9.61 x 3.82 in and weighs about 9 lb, so it can be mounted as a permanent part of a larger onboard electrical system. Samlex specifies a two-year limited warranty and lists the unit to UL 1564, with FCC Part 15 Class B EMI compliance.

• Charges two separate battery banks without an external isolator
• Selectable charging behavior supports standalone or loaded batteries
• Half-power mode accommodates lower-capacity battery banks
• Included temperature sensor improves charge compensation

Install the charger where cooling air can move freely around the enclosure and where both battery-bank cable runs remain practical. Use appropriately protected AC input wiring and correctly sized DC conductors for the installation, especially when the charger will also serve as a power supply. For related multi-bank charging equipment, browse more 2-Bank Battery Chargers.