LOKITHOR JTC4250 LiFePO4 12 V Jump Starter, 6/12 V Charger and Tester with App, 4250 A

The LOKITHOR JTC4250 combines a powerful 12 V jump starter, 6/12 V battery charger, battery and charging-system tester, power bank and multifunction LED light.

Battery-test results can be viewed on the device or transferred through the app for storage, evaluation and printing. The 13.3 mm² jump-start cables and heavy-duty clamps provide reliable current transfer.

The unit can be charged from a 100–240 V mains supply using the included EU or UK cable, or through USB-C.

Important: The jump-start function is suitable only for 12 V batteries. The device can charge 6 V batteries but cannot jump-start 6 V vehicles.

Main Functions

• 12 V emergency jump starting
• 6 V and 12 V battery charging
• Battery reactivation and maintenance charging
• Battery-condition and internal-resistance testing
• Cranking-system testing
• Alternator charging-voltage and current testing
• App-supported test-result storage and evaluation
• USB-A and USB-C power-bank output
• Work, warning and strobe lighting

Supported Battery Types

6 V and 12 V

• Lead-acid
• Flat-plate AGM
• Spiral AGM

12 V only

• LiFePO4
• Gel
• EFB

Safety Functions

Before starting or charging, the device checks the battery connection, resistance and internal resistance. It can detect:

• Reverse polarity
• Internal short circuit
• Poor clamp contact
• Battery unsuitable for starting or charging

Automatic shut-off occurs after 60 seconds in functions such as jump-start mode.

Technical Specifications

• Internal battery type: lithium iron phosphate (LiFePO4)
• Nominal voltage: 12.8 V
• Voltage modes: 6 V and 12 V
• Charging current: 6 A at 6 V and 12 V
• Suitable battery capacity: up to 120 Ah
• Starting current: 3000 A
• Peak current: 4250 A
• Internal capacity: 89.6 Wh / 7000 mAh
• Petrol-engine capacity: up to 10 L
• Diesel-engine capacity: up to 8 L
• Battery life: more than 2000 charge and discharge cycles
• Jump-start cable cross-section: 13.3 mm²
• LED light: 300 lm
• Light functions: three brightness levels, yellow warning light and strobe
• Power output: USB-A and USB-C
• Mains input: 100–240 V
• Operating temperature: −20 to 60 °C
• Charging temperature: 0 to 45 °C
• Storage temperature: −20 to 50 °C
• Dimensions: 264 × 146.2 × 109.5 mm
• Weight: 2300 g
• Protection rating: IP65
• Languages: German, English, French, Spanish and Chinese
• Certifications: CE, FCC, RoHS and UL

Scope of Delivery

• 1 × LOKITHOR JTC4250 jump starter
• 1 × USB-A to USB-C charging cable
• 1 × USB-C to USB-C charging cable
• 1 × jump-start clamp set with 13.3 mm² cables
• 1 × EU mains charging cable
• 1 × UK mains charging cable
• 1 × accessory storage bag

Supported Functions

After selecting a function, the device display provides step-by-step instructions, such as starting the engine or increasing the engine speed.

Standard Jump-Start Mode

With a starting current of 3000 A and a peak current of 4250 A, the device can start vehicles with severely weakened batteries.

All safety functions are checked before and during the starting process to help prevent hazards and damage.

With its capacity of 89.6 Wh, it is suitable for petrol engines up to 10 l and diesel engines up to 8 l.

If the vehicle battery is completely discharged below 1 V, defective or missing, Forced Start Mode can be selected.

Forced Start Mode

This mode is intended for starting vehicles with a deeply discharged, defective or missing 12 V battery. It cannot be used with 6 V batteries.

Warning: Some safety functions are disabled in this mode. Follow all instructions in the operating manual and carefully check the polarity and connections for possible short circuits before use.

Standard Battery-Charging Mode

The JTC4250 can charge and reactivate deeply discharged batteries with a remaining voltage of at least 1 V. For batteries below 1 V, Forced Charging Mode must be used.

Compatible battery types:

• 12 V: lead-acid, flat-plate AGM, spiral AGM, LiFePO4, gel and EFB
• 6 V: lead-acid and AGM

Forced Charging Mode

This function is designed to reactivate vehicle batteries with a voltage below 1 V. It ends automatically after five minutes.

If the battery voltage has risen above 1 V, continue charging with Standard Battery-Charging Mode.

Warning: Some safety functions are disabled in this mode. Follow all instructions in the operating manual and carefully check the polarity and connections for possible short circuits before use.

Battery Maintenance and Reactivation Mode

Regular use of Maintenance Mode helps preserve the battery’s condition by reducing sulphation, discharge and internal deterioration.

The battery is initially charged before the JTC4250 automatically switches to a four-hour pulse-charging programme. This can help the battery accept more charge and improve its cycling stability.

Battery Test

The JTC4250 can test lead-acid, flat-plate AGM, spiral AGM, gel and EFB batteries.

It supports battery-rating standards including:

• CCA
• DIN
• IEC
• EN
• SAE

Battery-Test App

The “Bat Test” app provides detailed test data that can be evaluated and saved.

This allows workshops to store test reports and transfer the results to a computer or printer.

Alternator Test

The alternator test checks its voltage and current output.

During the test, the vehicle’s electrical consumers are switched on and the engine speed is increased to 2500–3000 rpm. Follow the instructions shown on the device display.

Cranking-System Test

This function checks important basic conditions required for successful engine starting.

The results may indicate problems such as:

• A defective starter motor
• A defective battery
• Damaged or incorrect wiring
• Internal short circuits in the starter motor or battery

Power-Supply Mode

Power is supplied through the USB-A and USB-C connections. The JTC4250 offers two operating options:

• Voltage-converter function: When connected to a 100–240 V AC supply using the charging cable, the digitally regulated output supports devices from 5 to 20 V, with up to 6 A and a maximum output of 90 W.
• Power-bank function: Without a mains connection, the internal battery supplies a digitally regulated output from 5 to 20 V, with up to 5 A and a maximum output of 60 W.

High-Power LED Work Light

The integrated 300 lm LED light offers the following modes:

• Continuous light with 100%, 50% or 10% brightness
• Yellow warning light
• Strobe light