ES Energysafe 12V 4A Smart Battery Charger – DUO Maintainer for Lead-Acid and LiFePO4 Lithium

ES Energysafe DUO 12V 4A smart battery charger: lead-acid and lithium in one unit

This battery charger from the ES Energysafe Battery range combines charging and battery maintenance in a single fully automatic unit. It is designed to keep the battery of your motorcycle or car in good condition when the vehicle sits unused for long periods, for example over the winter, and to recharge it after it has gone flat. It works with 12V lead-acid, AGM, GEL, EFB and LiFePO4 lithium batteries.

Charging modes of the charger and maintainer

Use the MODE button to pick the right program for your battery. A long press of 5 seconds switches between the group of normal modes and the group of additional functions. The unit remembers the last mode you selected and resumes it every time it is plugged into the mains.

Normal modes

• 12V STD: up to 14.5 V, for standard lead-acid batteries.
• 12V AGM: up to 14.8 V, for AGM batteries.
• Winter mode (snowflake): charging at ambient temperatures between -20 °C and +5 °C.
• 12V M (maintenance): up to 14.4 V and 1 A, to keep the battery topped up during periods of inactivity.

Additional functions

• Recond: up to 16.5 V and 1.5 A, for deeply discharged 12V batteries.
• 12V LFP: up to 14.6 V, for 12V lithium iron phosphate (LiFePO4) batteries.
• SUPPLY: works as a 12V power supply with a maximum output of 3 A.

Battery charger for motorcycle and car

It is a versatile motorcycle battery charger and car battery charger: it suits 12V starter batteries in cars and motorcycles, whether lead-acid, AGM, GEL, EFB or LiFePO4 lithium. With a maximum current of 4 A it is ideal for recharging and maintenance; for large-capacity batteries, bear in mind that charging will take longer.

Lithium battery charger: LiFePO4 only

The LFP mode is designed only for 12V LiFePO4 lithium batteries. The manufacturer expressly forbids charging any other type of lithium battery with this unit.

Battery maintainer for the winter

As a battery maintainer, it keeps the charge in your motorcycle, car or seasonal-vehicle battery while the vehicle is parked, preventing it from going flat. The 12V M maintenance program and the winter mode are designed for this use. Remember: never charge a frozen battery.

Safety and protections

• Short-circuit protection.
• Overload protection.
• Overheating protection.
• Reverse-polarity protection (the display shows "Err").
• IP65 waterproof rating and protection class II.
• On-screen indicators: "bAd" (faulty battery), "FUL" (fully charged) and "Err" (reverse polarity or short circuit at the clamps).

How to use the battery charger

1. Check that the battery is 12V and clean the terminals. Work in a well-ventilated area.
2. With the charger unplugged, connect the red clamp (positive) to the battery's positive terminal.
3. If the battery is still in the vehicle, connect the black clamp (negative) to the chassis, away from the battery and the fuel line. If you have removed the battery, connect it to the negative terminal.
4. Plug the charger into the mains (220-240 V) and select the mode with the MODE button.
5. When finished, unplug the charger and remove the negative clamp first, then the positive one.

How long does it take to charge?

The approximate time is the battery capacity divided by the charging current: hours = Ah ÷ A. For example, a 40 Ah battery at 4 A would take about 10 hours to charge from flat. A partially charged battery needs less time.

Technical specifications

Frequently asked questions

Can it charge lithium batteries?

Yes, but only 12V LiFePO4 lithium batteries, in LFP mode. It must not be used with other types of lithium battery.

Is it a charger or a battery maintainer?

Both. It recharges flat batteries and, once they are full, can hold them at their optimum level with the maintenance program.

Does it work with 24V batteries?

No. This charger is for 12V batteries only. Do not charge batteries of any other voltage.

Can I leave it connected over the winter?

It is designed to maintain a motorcycle or car battery when the vehicle is not used for long periods. Select the maintenance program or the winter mode depending on the temperature.

What does "bAd" mean on the display?

It indicates a faulty battery. The manufacturer recommends replacing it. The same applies to a lead-acid battery that has stayed below 3 V for a long time and cannot be brought back up by the charger.

What does "Err" mean?

The clamps have been connected with reversed polarity or there is a short circuit across them. Unplug the charger and check the connection.

What is the Recond mode for?

It is a program of up to 16.5 V and 1.5 A for deeply discharged 12V batteries.