400A car battery booster: the lightweight jump starter for city cars
This car battery booster with a 400 A peak current is designed for small 12 V cars: city cars, compact cars, and small petrol engines. Lightweight (around 600 g), it fits in a door pocket and is enough to restart an engine after a battery has been drained by the cold or lights left on, without having to wait for roadside assistance.
Why choose this mini car battery booster
- 400 A peak current: sufficient power for small engines, without paying for unnecessary capacity
- External battery: the lithium battery charges phones and tablets via USB, with fast two-way charging
- 3-mode LED lamp: standard, strobe, and SOS for nighttime roadside emergencies
- Multiple protections: overcharge, short circuit, and over-discharge are monitored
- Three versions: model with a red and black digital display, or standard red and black models supplied with their case
What vehicles is this 400A booster designed for?
A 400A booster is the right choice for a petrol city car, a small compact car, a 12 V quadricycle, or a motorcycle. It gives peace of mind to drivers who rarely drive and leave their car for several days without starting it. However, for a diesel car battery booster for a large-displacement engine, SUV, or van, you should aim for 1500 to 3000 A: this model will not reliably start them, especially in extreme cold.
400A booster or jump cables?
Cables require a second car and careful connection. The mini car battery booster is self-sufficient: you connect it yourself, completely safely thanks to electronic protections. For a small car, it is the simplest and lightest solution, to keep on hand all year round.
Technical specifications
Voltage: 12 V. Peak current: 400 A. Stated capacity: 18,000 to 20,000 mAh (manufacturer's stated value). Lithium-ion battery, 4 cells, stated conversion rate of 85 to 90%. Full charge in 5 to 6 hours. Weight: around 0.6 kg. USB ports for charging your devices.
Instructions and safety
Turn off the ignition and accessories. Connect the red clamp to the + terminal, the black one to the - terminal or a metal ground. Turn on the booster, wait for the clamps to signal, then start. If the engine does not start, wait a minute before trying again, without making more than three attempts in a row. Disconnect in the reverse order. Recharge the booster after each use and at least every 3 months.
Frequently asked questions
Is a 400A booster enough for my car?
Yes for a city car or a small 12 V petrol car. For a diesel, SUV, or van, choose a more powerful model.
What is the difference between the three versions?
The display version shows the charge level in numbers; the standard red and black versions are supplied with a storage case.
Can it charge a phone?
Yes, via its USB output, like a standard power bank.
How long does it hold its charge?
Several months when stored. Recharging every 3 months ensures it will be ready for the day you need it.
Does it work in cold weather?
Yes, but the cold reduces the performance of any lithium battery: store it in the cabin rather than the boot in winter.
The right size for a small car: lightweight, simple, always ready in the door pocket.
Type: Compact 12 V car battery booster
Peak current: 400 A
Capacity: 18,000 to 20,000 mAh (stated)
Recharge: 5 to 6 h
Weight: Around 0.6 kg
Versions: Red and black digital display, standard red with case, standard black with case
Compatibility: 12 V city cars and small petrol engines
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