Car batteries can be counted on to fail at the most inopportune time. Imagine you're about to return home from shopping and your battery simply hasn't got enough juice in it to start your car. Now you're immobile and stuck away from home. Sure, you could put on your charm and see if you can borrow a jump off a stranger or call a breakdown service, but these options are far from ideal.
The best way to avoid this is to buy a portable battery charger. Keep one of these in your car and you'll be able to start your stricken car with ease. We've found the best portable battery boosters so you'll never let a flat battery flatten your day.
If it's a battery charger for conditioning and charging your battery at home that you need, read our article on regular car battery chargers.
The best portable battery chargers
1. NOCO Boost Sport GB20
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A powerful and compact offering from NOCO, this battery booster can restart an engine up to 4.0-litres from dead with ease. Spark-proof protection and reverse polarity protection will ensure you won't ruin your battery. It also comes with an LED torch and USB slot so you can use it as a power bank too.Pros:Powerful enough for most carsGreat qualityCons:A hard case to protect it costs extra
2. CTEK CS FREE
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The brand new CS FREE portable battery charger is the both the easiest and smartest portable battery charger. It can charge a dead battery with enough power to start in 15 minutes and thanks to its Adaptive Boost, does so without damaging the vehicle's electronics. If you hook it up to a solar panel or 12V battery, it can also be used as a proper battery charger too. It has the usual power bank functions too, and can hold its charge for up to a year. Recharges via USB-C. Pros:Simplicity of useJump start, charger, and power bank Can charge dead batteries Comes with UK and EU adaptorsCons:Pricey
3. Halfords Advanced Lithium Jump Starter
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A pricy but effective portable battery charger from Halfords, this portable battery booster will be able to recharge an engine up to a 3-litres in size. It should be noted that this battery is no good for restarting totally dead batteries but will help jump batteries with the power of units far bigger in size. It also comes with a USB port and torch.Pros:Plenty of power for its sizeCons: Cannot jump start dead batteries
4. Ring RPPL400 High Power Lithium Jump Starter
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Ring's RPPL400 is ideal for those who have own a car with a large engine. The RPPL400 is suitable for petrol engines up to 6.0 litres and diesels up to 3.5 litres. It's still small, which is crucial, weighing about 1kg and being 25cm in length. We like how the unit manages the power between the jump starter and the vehicle, which helps protect the battery. It is, of course, a power bank too, has an LED light, and charges via micro USB. Pros:Good for up to 6.0-litre enginesRemains light and compactRing Automotive qualityCons:Overkill for most people
5. Solar Car Battery Trickle Charger
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A trickle charger is a great way of preventing your battery from going flat and this solar-operated model will keep your battery powered up for even longer. Completely water-resistant it'll be ideal if you're leaving your car idle for an extended period of time. And when you're done simply chuck it in the boot until needed. Pros:Keep your battery from going flatAmorphous solar panel means it'll charge without direct sunlightCons:Will not restart a dead batteryThis portable example is waterproof too
6. 12V Portable Car Jump Starter
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If you're wanting a portable battery booster with an air compressor on a budget, this product is ideal. Offering a torch, battery charger, air compressor and 12V power supply it's still a versatile tool. Suitable for cars with engines up to 2.0 litres. There is no three-pin socket or USB slot however, so charging your phone up may be a bit harder.Pros:includes several useful features in one packageCons:Lacks modern USB socket
What you need to know about portable battery chargers:
What do I need to bear in mind?
Before you buy a booster you should check that it'll work with your engine. The bigger your engine, the more power will be required for it to work. Our picks will cover most new cars meaning you'll have peace of mind with one of these - just make sure to double-check. It's also worth mentioning that some of these boosters will not work with cars fitted with Stop-Start.
What other features should I look for?
Aside from charging your car's battery, there are a number of useful features that you should look for in a portable battery booster. Look and see if it has a torch, most do and it can be invaluable if you're stranded at night.
Also look for USB charging, this'll mean you'll be able to plug your phone in and charge it up, again a great feature if you've broken down and your phone battery is low.