Buying a car jump starter: how to choose the right one

A flat battery often strikes at the worst possible time: in a car park, on a camping trip or just before you leave for work. With a car jump starter, you can sometimes start a 12V vehicle yourself, without another car or traditional jump leads. However, many models appear more powerful and versatile than they are in practice.

The main pitfalls usually come down to three things:

• Peak current is mistaken for actual starting power. A high amp rating alone doesn’t tell you whether a jump starter is suitable. Compatibility with petrol and diesel engines, battery condition and the connecting cables all matter too.
• A high mAh rating doesn’t automatically mean more usable energy. Manufacturers may state capacity in different ways. So check the weight, dimensions, charging time and stated starting current as well.
• Extra features can distract from the main job. An air compressor, power bank or LED light can be handy, but first check that the device is suitable for your vehicle and that its safety features are clearly described.

Pay attention to the product type too. A car battery charger runs from mains power and charges the battery gradually. A car jump starter, emergency car starter or portable jump starter, on the other hand, delivers a high current for a short time to start the engine. A charger doesn’t automatically replace a jump starter.

Which specifications matter?

1. 12V compatibility and engine size

Check whether your car, motorbike, campervan, boat, tractor or van uses a 12V battery. Then check the maximum engine capacity the manufacturer states for petrol and diesel engines. Diesel engines generally need more starting power than petrol engines.

A model rated for, say, petrol engines up to 6.0 litres and diesel engines up to 4.0 litres isn’t automatically suitable for a heavy van or lorry. For SUVs, campervans and larger vehicles, it can make sense to allow for some extra capacity. Use the stated figures as a guide and check your vehicle handbook if you’re unsure.

2. Peak current, starting current and cables

Peak current is a brief maximum rating. Starting current gives you a different idea of what the car battery booster can deliver when starting the engine. So don’t just compare 1200A, 3000A or 6000A. Also check:

• the stated compatibility with petrol and diesel engines;
• the thickness and length of the jump leads;
• the quality of the clamps;
• whether there’s a BOOST function for very low battery voltage;
• the maximum starting time and cooling period stated in the manual.

Smart jump leads with protection against reverse polarity, short circuits, overheating and overcurrent reduce the risk of incorrect use. They don’t remove the need to connect everything correctly.

3. Safety, storage and ease of use

A portable jump starter should be easy to read and carry. An LCD screen may show the charge level, temperature or connection status. An LED light with an SOS or flashing mode is useful if you break down in the dark.

Also check:

• whether the jump starter needs to be fully charged before first use;
• how often the manufacturer recommends charging it during storage;
• whether it needs to be kept dry and protected;
• whether the manufacturer warns against using it with a damaged, leaking or frozen battery;
• what warranty period and contact details are provided.

Claims such as ‘starts dozens of times’ or ‘stays charged for months’ are brand or product claims. Don’t treat them as guaranteed results in all conditions. Actual performance depends on factors including temperature, battery condition and vehicle type.

Our recommendations for different users

Suitable for: Budget-conscious beginners

GOOLOO GP2000 Car Jump Starter Power Bank

Why it suits this type of user: According to the product description, this 2000A car battery booster is designed for 12V vehicles with petrol engines up to 8.0 litres and diesel engines up to 6.0 litres. That makes it suitable for many cars, SUVs and motorbikes.

How this product avoids the pitfall

The stated vehicle and engine sizes make it easier to compare than relying on a high amp rating alone. According to the product information, the smart cables have several safety features.

Main benefit and highlights

Power bank with two USB outputs, a 400-lumen light and a stated weight of around 545 grams.

Suitable for: Buyers looking for premium quality

GOOLOO GP4000 Jump Starter Power Bank

Why it suits this type of user: This model is aimed at drivers of larger 12V vehicles. The product description states a peak current of 4000A and support for petrol and diesel engines up to 10.0 litres.

How this product avoids the pitfall

Vehicle compatibility is clearly stated. According to the product information, it has ten types of protection and comes with metal clamps.

Main benefit and highlights

Two USB ports, a USB-C input, an LED light and a BOOST function for very low battery voltage.

Suitable for: Specific needs and frequent users

YUSMAN Car Jump Starter 5000 A with air compressor

Why it suits this type of user: For anyone who wants to carry a tyre inflator as well as a car jump starter. The product description states that the compressor reaches up to 150 PSI and that the device supports 12V vehicles.

How this product avoids the pitfall

According to the product description, the LCD display shows tyre pressure and device status. The smart clamps warn you if they’re connected incorrectly.

Main benefit and highlights

5000A peak current, stated capacity of 21800mAh, an air compressor and four LED modes.

Suitable for: Outdoor enthusiasts and campervan owners

Porbi S306 Car Jump Starter 1200A

Why it suits this type of user: At around 330 grams, its compact body is handy for a motorbike, boat or car, or to keep in a rucksack when space is limited.

How this product avoids the pitfall

The specifications state both a peak current of 1200A and a starting current of 600A. This makes the difference between the two figures clear when comparing models.

Main benefit and highlights

Stated battery capacity of 12800mAh, LCD display, USB output and LED lighting with SOS and flashing modes.

How to use a car jump starter safely

Always read the manual for your chosen model. The usual steps are:

1. Switch off the car and put it in park or neutral.
2. Connect the red clamp to the positive terminal.
3. Connect the black clamp to the negative terminal or a suitable unpainted metal grounding point, depending on the instructions.
4. Switch on the jump starter and start the engine within the stated time.
5. Let the engine run briefly, then remove the clamps in the order given in the manual.
6. Recharge the jump starter after use.

Don’t use a booster if the battery is visibly leaking, cracked or frozen. Don’t keep trying to start the engine over and over either; allow the device to cool down between attempts. A jump starter won’t fix a worn-out or faulty battery in the long term.

Frequently asked questions

Can a jump starter start a diesel car?

It can, as long as the model is suitable. Check the stated diesel engine capacity and 12V compatibility specifically. A model listed only for small petrol engines isn’t a sensible choice for a diesel campervan or van.

How often should I charge a portable jump starter?

Follow the manufacturer’s instructions. Product information for various models recommends charging every two to six months when the device isn’t in use. Check the charge level before a long journey and recharge it after use.

Is a jump starter with a power bank also a car battery charger?

No. The power bank function is usually for charging phones, tablets or other USB devices. A car battery charger is designed to charge a vehicle battery in a controlled way from mains power. So, to maintain a lead-acid battery, you’ll need a suitable smart charger, not just a jump starter.