Lithium Series

OptiMate has developed a special Lithium battery charger series for vehicles! Why? You can read all about it below. If you want to go to our Lithium battery chargers directly, click here.

Lithium batteries are popular replacements for bulkier and heavier lead-acid batteries. A Lithium battery is lighter, smaller and delivers better engine start performance than the equivalent lead-acid battery.

A 12V lead-acid battery has 6 x 2V cells-in-series, each cell charges up to 2.4V, together the total battery charging voltage is 14.4V. As a result, all 12V vehicle systems are designed to match lead-acid battery technology with normal operating range of 12V to 14.4V.

The matching Li-Ion battery technology on the other hand is Lithium Ferrous Phosphate (LiFePO4 / LFP). A 12.8V LFP battery has 4 x 3.2V cells-in-series. Each cell charges up to 3.6V, together the total battery charging voltage is 14.4V. A 4S (4-cells-in-series) LFP battery has a safe operating range of 12.8V to 14.4V.

When the engine is cranked (turned over) the starter motor draws very high current (measured in Cranking Amps / CA) from the battery. To deliver cranking amps the battery needs to have reserve energy stored that is measured in Amp-hours (Ah). A LFP battery needs less reserve energy (Ah) to deliver the same cranking amps (CA) as a lead-acid battery. To keep cost down, a LFP engine start battery typically has 2-3 times less reserve energy capacity (Ah) than the equivalent lead-acid battery for the same vehicle.

State Of Charge (S.O.C.)
A battery needs a minimum State Of Charge level (S.O.C. %) to deliver its rated cranking Amps, below that level the cranking amps (CA) it can deliver reduces and the engine will struggle to start. Voltage is a good indication of the battery’s State of Charge (S.O.H. %), a lower voltage means less charge / reserve energy remains. A LFP battery works best if its voltage is at 13V (±30% S.O.C) or higher. A sealed AGM lead-acid battery works best from 12.4V (±50% S.O.C.) and higher.

During long term vehicle storage (e.g. over winter) the vehicle’s ‘always on’ electronics slowly uses up the reserve energy (in Amp-hours) of the battery. In the same vehicle, an LFP lithium battery with lower rated reserve energy capacity (Ah rating) discharges faster than a larger lead-acid battery. OptiMate Lithium LFP battery chargers have a special lithium 24-7 SAFE maintenance program that continuously monitors the LFP battery’s voltage and will automatically keep it at a 70% or higher energy level.

State Of Health (S.O.H.)
Lithium LFP batteries can normally receive high charge current when the battery is at 12V or higher, but below 12V it loses the ability to accept high current charge. The further below 12V the less the battery’s ability to accept normal charge. Below 8V it is in a critical State Of Health (S.O.H.) however. At low voltage the LFP battery can only tolerate low current until its voltage is above 12.8V again. An OptiMate Lithium LFP battery charger delivers a SAFE low current recovery charge. It continuously checks cell health as it slowly nurses the lithium LFP battery back towards full health (above 12.8V), when it once again can receive normal charge.

Battery Management System (BMS)
Some lithium-ion batteries have a smart resettable BMS— Battery Management System— to protect it from damage, it shuts down if it senses the battery’s voltage is too low. All OptiMate Lithium LFP chargers therefore have a BMS pulse wake-up system that will reset and reactivate the battery correctly.

Lithium batteries are more expensive than lead-acid batteries. Therefore, to protect your investment use an OptiMate Lithium LFP battery charger. It will guarantee your Lithium LFP battery will last longer and always perform stronger.

Lithium Series FAQs

General lithium LFP FAQs