Brand: OptiMATE Battery Chargers
Lithium batteries offer an incredible weight savings, but your old lead-acid battery charger will ruin them. This professional-grade battery charger is designed just for use with 12-volt nominal (12.8v) lithium (LiFePO4 / LFP) batteries.
The Optimate LFP 4s Battery Charger is an advanced multi-step charger that monitors battery condition with four separate tests before, during, and after the charging and balancing sequence. Selectable modes let you override internal BMS shutdowns to recover deeply-discharged batteries. "Tune" mode provides a steady 13.6 volt power supply so you don't burn up your battery by programming or tuning with the engine off.
Pre-Qualification Test - Checks battery condition and ambient temperature. This determines which charging program will be used.
SAVE - If necessary, a battery found to be over-discharged is charged at a low recovery rate. The battery is continually tested during this low-voltage recovery step to determine when the battery is ready to go on to the next charging step.
Bulk Charge - Charge current is adjusted according to battery capacity and condition in order to fully charge the battery as quickly as possible without causing new problems.
Dead Cell Check - Throughout all of the charging steps, the Optimate charger compares charging progress against an ideal charging curve for LiFePO4 batteries. If the charger detects one or more dead cells, charging will stop and a warning will light up.
Equalization - This 10-minute process delivers higher-voltage pulses of current to balance the charge in the individual cells.
Retention Test - Charging stops for 30 minutes while the Optimate tests and monitors the battery for 30 minutes. If the battery passes the first test, an extended (up to 12 hour) test for self-discharge is conducted.
Maintenance Charge - 30 minutes of charging, followed by 30 minutes of rest, followed by a test for lost voltage. If a parasitic draw is detected, the charge cycle will be extended until the draw drops below 1A. If battery voltage suddenly drops, the charger will automatically return to the Equalization step.
The Optimate 4s will start again at the Retention Test 24 hours after charging began, and will start again every 24 hours as long as the battery is connected. Although LiFePO4 batteries do not self-discharge like lead-acid batteries do, this charger is designed to be connected during long-term storage. This makes it especially useful when the battery is left in a vehicle with a small (below 0.5 Amp) parasitic drain. The charger can also be wall-mounted to save workbench space.
The charging routine is fully automatic, with no programming required. Suitable for use with any 12 volt LFP battery between 2Ah and 120Ah. Capable of charging a typical 50Ah battery in approximately 10 hours. Not for 6 volt or 16 volt lithium batteries, or for lead-acid batteries of any voltage.
Operates on 100 - 240 VAC input voltage (50-60Hz). This version has a 6 foot AC supply cord with a 2-prong North American (USA & Canada) plug. Draws less than 0.5W when not connected to a battery (listed by the California Energy Efficiency Commission). Includes clamp-type charging cable and weatherproof ring terminal cable, each with a quick-release 2-pin SAE plug that connects to the 6 foot charge lead on the charger. The charger body features built-in wall mounts.
Note: Prior to 2019, this model was labeled as the LFP 4s 12V 9.5A.