That sinking feeling when your engine won’t turn over is one of the most unwelcome of emotions, but almost every driver has been there at some point or another. While a call to your breakdown service wll fix the issue, the best car battery chargers can help you mitigate the disruption to your day, at your own will.
But buying a car battery charger isn’t the most straightforward task. First, there are different types of car battery chargers to choose from. There’s also a choice of connectors, depending on whether you’re regularly maintaining your car battery or just recharging as a one-off.
From traditional car battery chargers to portable and solar-powered ones, there are options available to suit a range of budgets. However, buying the cheapest doesn’t always mean bagging a bargain. If you’re caught with a flat battery, the very last thing you want to find out is that the tool you’ve invested in to remedy the matter is a dud.
With that said, read on for our buying guide on how to buy the right car battery charger for you, alongside our roundup of some of the best options available.
Bag a saving on the CTEK 12V Portable Charger
This supremely versatile charger is currently available for just £260, £11 lower than its average price on Amazon. Considering the CTEK 12V boasts a slew of enviable features, including the ability to charge laptops and mobile devices, this is a deal to take advantage of.
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How to choose the best car battery charger for you
How do car batteries work?
The electronics in our vehicles are configured in a very smart way, in that they are almost always powered by the engine. As the crankshaft spins, not only does it force the pistons to propel the vehicle, but it also turns an alternator at the other end. This creates electricity to power the lights, computer units and put charge back into the car battery.
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When a car isn’t driven, low-power features, such an immobiliser or alarm, continue to draw from the battery since there’s no power being generated by the alternator. At the end of lockdown restrictions, many drivers found that their car batteries were dead from their vehicles not being driven for several weeks.
Car batteries are not power banks, so they don’t store electricity. Without going into the science of it all, they generate the energy needed through lead-acid chemical reactions. When a car is started, a very high current is sent in a very short burst to the crankshaft to get it moving. The alternator then does all the work on the electricity front.
It’s important to note that car battery chargers are not jump starters. A jump starter will offer the engine the short burst needed to get it going, but from that point on, it’s the alternator that recharges the battery. This is why, if you’re ever jumpstarting your car, you’re asked to run it for a good while to replace enough of the battery, so that you don’t require a jump start when you come to drive again immediately afterwards.
Which car battery charger is best?
The first question you should ask yourself is what you plan to use a car battery charger for. If you have a motorcycle or classic vehicle, you might wish to purchase one with eyelet connectors. These hook onto the positive and negative terminals of the battery permanently and are secured with nuts. The battery is then connected and disconnected from the charger through a cable, which enables easy access.
If you’re only needing a one-off charge, then easy-snap-on crocodile clips might be better. If you’re a flat dweller or your off-street parking doesn’t have convenient access to mains power, you might need to consider a portable or solar power charger.
For more information, see our extended buyer’s guide below our mini-review roundup.
The best car battery chargers you can buy in 2022
1. NOCO Genius10 Smart Charger: Best portable car battery charger
Price: £130 | Buy now from Amazon
One of the best names in the business, NOCO has a reputation for delivering innovative features with its battery devices. The compact NOCO Genius10 offers great value for money, and it’s smart enough to monitor the ambient temperature and adjust its charging rate to avoid degradation of the battery.
With a comprehensive array of modes, terrific build quality and intuitive functionality, the Genius10 is a bit of a, er, genius. If the price is a little bit beyond your budget, or you have a smaller vehicle, there are other NOCO Geniuses (Genii?) with lower amperage that will deliver enough for your needs.
Key specs – Size: 18.3 x 9.4 x 6cm (LWH); Weight: 1.5kg; Voltage: 6V, 12V; Max current: 10A; IP rating: IP65 Crocodile clips: Yes; Eyelet connectors: Yes; Torch feature: No; Mains or portable: Portable; Battery compliant: Lead-acid/AGM/Lithium+; Stop/start compliant: Yes; Maintaining: Yes; Jumpstarting: No; Operating temp: 20-40°C
NOCO GENIUS10UK, 10A Fully-Automatic Smart Charger, 6V and 12V Portable Heavy-Duty Car Battery Charger, Battery Maintainer, Trickle Charger and Battery Desulfator with Temperature Compensation
£123.70 Buy now
2. AA 12V Solar Trickle Charger: Best budget solar panel maintainer
Price: £43 | Buy now from Amazon
Got a vehicle that sits in the sun a fair bit between uses? This is a brilliant battery charger that uses solar power, so eventually it will earn its keep. While it won’t save you from an immediate flat battery situation, the solar panel sits on the dash, collecting sufficient energy to trickle-charge the battery.
Now low-power functions, such as the immobiliser, won’t have such a frustrating effect when you do come to start the car (after disconnecting first). What’s more, it switches into maintenance mode to protect the battery once it has been fully charged.
Key specs – Size: 44 x 34.5 x 6.2cm (LWH); Weight: 2.2kg; Voltage: 12V; Max current: <1A; IP rating: N/A; Crocodile clips: Yes; Eyelet connectors: No; Torch feature: No; Mains or portable: Portable; Battery compliant: Lead-acid/AGM/Lithium+; Stop/start compliant: Yes; Maintaining: Yes; Jumpstarting: No; Operating temp: Unspecified
AA 12 V Car Solar Battery Trickle Charger 4.8 W AA1432 - for Vehicles and Caravans - Battery Connectors Included
£41.99 Buy now
3. Ring Automotive RSC806 Smart Battery Charger: Best budget battery charger
Price: £31 | Buy now from Amazon
Ring, alongside NOCO and CTEK, has a good reputation in combining cutting-edge tech with affordability. With a clear display, the RSC806 is lightweight and fairly intuitive to use (even if the instructions aren’t the best). Configured with “smart” technology, the RSC806 not only reconditions the battery, but also features a cold weather mode for drivers in cooler climes. Depending on your levels of patience, budget and type of vehicle, the Ring smart charger also comes in 8A and 4A versions, better suited to vans and city cars respectively.
Key specs – Size: 18.3 x 10.1 x 6.3cm (LWH); Weight: 1.13kg; Voltage: 6V, 12V; Max current: 6A; IP rating: IP65; Crocodile clips: Yes; Eyelet connectors: No; Mains or portable: Mains; Battery compliant: Lead-acid/AGM/Lithium+; Stop/start compliant: Yes; Maintaining: Yes; Jumpstarting: No; Operating temp: 20-50°C
4. CTEK (CS FREE) 12V Portable Charger: Best battery charger for versatility
Price: £286 | Buy now from Amazon
If you’re shelling out this kind of cash, you want something that will deliver. The CTEK (CS Free) is a portable charger and a power bank. A hugely versatile device, the internal power bank supports laptops and mobile devices as well as your car battery. It can provide an “‘Adaptive Boost” jump in up to 15 minutes and stays charged for up to a year: perfect for glovebox storage.
There’s an optional solar panel accessory (albeit as a not-so-budget friendly £320 add-on) but the reputation of CTEK doesn’t falter. The build quality of this 4-in-1 charger is brilliant, easily justifying the higher price.
Key specs – Size: 24.8 x 9.8 x 7.8cm (LWH); Weight: 1.4kg; Voltage: 20V; Max current: 130A; IP rating: IP65; Crocodile clips: Yes; Eyelet connectors: Yes (extra ££); Mains or portable: Portable; Battery compliant: Lead-acid/AGM/Lithium/LFP/EFb+; Stop/start compliant: Yes; Maintaining: Yes; Jumpstarting: Yes; Operating temp: -20-50°C
CTEK CS FREE Portable Charger 12 V, 4-in-1 Power Bank 12 V, Power Bank Solar, Outdoor Power Bank for Car, Phone, Computer, Intelligent Battery Care, Power Bank Jump Starter with Adaptive Booster
£277.68 Buy now
5. Halfords Advanced Smart Battery Charger Plus: Best charger for simple use
Price: £45 | Buy now from Halfords
Supporting a wide range of battery types and start/stop technology, what this Halfords charger lacks in clear instructions it makes up for with its intuitive functionality, decent performance and lower price. The interface doesn’t feature a fancy LED screen, just simple lights and buttons that do exactly what you need.
A nicely sized, mains-powered device, you can indicate if it’s cold weather and the device will manage power delivery more intelligently to protect the battery. What’s more, there’s a choice of eyelet or crocodile connectors.
Key specs – Size: 16.8 x 6.5 x 3,8cm (LWH); Weight: 0.6kg; Voltage: 12V; Max current: 5A; IP rating: IP65; Crocodile clips: Yes; Eyelet connectors: Yes; Mains or portable: Mains; Battery compliant: Lead-acid/gel/Lithium+; Stop/start compliant: Yes; Maintaining: Yes; Jumpstarting: No; Operating temp: 10-40°C
6. Draper 53491 6V/12V Smart Charger and Battery Maintainer: Best budget portable battery charger
Price: £67 | Buy now from Amazon
Using 10 steps (from battery devulcanisation to maintenance charge) to recondition the batteries it’s attached to, the Draper 53491 Smart Charger and Battery Maintainer supports lead-acid and lithium batteries. The digital display gives an indication of the power delivery and status of the programme and enables drivers to scroll through the different modes, including ‘winter charging mode’ (which it supports to a very chilly -20°C), very easily.
There’s a 12-month warranty on parts and labour, though Draper is a brand associated with rigorous professional workshop quality, so you’re unlikely to experience issues with this battery charger. Its portability also makes it great for flat dwellers and other motorists without mains access near to where they park.
Key specs – Size: 30.9cm x 16.3cm x 7.6cm (LWH); Weight: 1.14kg; Voltage: 6V, 12V; Max current: 10A; IP rating: IP65; Crocodile clips: Yes; Eyelet connectors: Yes; Mains or Portable: Portable; Battery Compliant: Lead-acid/AGM/Lithium+; Stop/Start compliant: Yes; Maintaining: Yes; Jumpstarting: No; Operating temp: -20°C-40°C
Best car battery chargers: Extended buyer’s guide
What else should I consider?
You also have to consider what kind of battery you have: lead-acid, AGM (an advanced version of lead-acid) or lithium-ion. Some batteries are versatile enough to support multiple technologies, others not so much. You often find versatility has a direct correlation with price.
Finally, you’ll want to consider the maximum current the charger can support (the higher the current, the faster the charge) and what IP (ingress protection) rating it has. This basically tells you how dust- and waterproof the device and device casing is. For instance, IP68 is a great rating: it’s a completely sealed unit that can tolerate being submerged in up to one metre of water. IP44 can protect against dust particles bigger than 1mm and a light splash of water.
Can’t I just replace my car battery?
The materials used in a battery are susceptible to degradation, and user behaviour (among other factors such as weather and age) can affect the life of the battery’s materials.
Charge and discharge rates of mobile phone, electric vehicle and regular 12V car batteries are heavily researched by manufacturers to best understand what kind of life expectancy consumers can anticipate from their devices. Age can give you an indication of whether the battery is completely dead or just flat, but trying to recondition an existing battery with a smart charger is ultimately cheaper than replacing it.
FAQs
Is there a battery charger that will charge a completely dead battery? ›
If you're looking for a charger that can restore a sulfated battery, we suggest the X2Power 7.5 amp charger, which comes with a Recovery mode for deeply discharged or sulfated batteries.
Is it better to disconnect a car battery or use a trickle charger? ›Trickle chargers are designed to maintain a charge equal to the self‐discharge rate of the battery ( 2.23 to 2.25 volts per cell) and it is recommended they be disconnected from the battery to prevent the possibility of overcharging.
What to look for when buying a car battery charger? ›- Voltage. A battery charger's rated voltage is the measure of its strength, essentially. ...
- Amperage. Amperage is the measure of current the charger will put through it while it's working. ...
- Automatic Function. ...
- Safety Features.
- Limit short trips. Quick car rides prevent your car's battery from fully charging. ...
- Keep your battery tightly fastened. ...
- Turn off all lights when you get out of the vehicle. ...
- Control the corrosion. ...
- Test your battery often. ...
- Don't use electronics with the engine off.
The safest amp to charge car batteries is from 4 to 7.5 amps. Charging within this range ensures the vehicle battery won't overcharge, overheat, or be damaged in the process. Yes, you can safely charge a minimum voltage 12-volt battery with this amp rating, though it will be pretty slow.
Can you charge a completely drained car battery? ›If that does not seem to work, however, car battery chargers can regenerate all of the charge into a battery. Keeping a car battery plugged in for twenty four hours can fully recharge your battery, and chargers are typically quite affordable.
Can I leave a trickle charger on a car battery overnight? ›Some trickle chargers can safely be left connected for months without doing harm to your battery, providing an easy long term battery maintenance strategy. Others may only be left connected for a few days at most.
What's the difference between a battery charger and a battery maintainer? ›The two main options for achieving this are either a battery maintainer or a trickle charger. A battery maintainer is designed to keep the battery fully charged, while a trickle charger is meant to slowly recharge the battery over time.
What is the safest way to charge a car battery? ›- PREPARE THE BATTERY. ...
- TURN OFF ALL ELECTRONICS. ...
- REMOVE THE NEGATIVE CABLE FIRST, THEN POSITIVE. ...
- CLEAN THE BATTERY TERMINALS. ...
- CONNECT THE CAR BATTERY CHARGER. ...
- REMOVE THE CHARGER AFTER CHARGING IS COMPLETE.
- Baseus 160W USB PD 3.0 car charger. The 160W Baseus car charger is one of the fastest and best car chargers out there right now. ...
- NekTeck USB Car Charger. Nekteck 18W 4-port USB-Car charger. ...
- Spigen ArcStation 65W PD charger. Spigen 65W ArcStation Car Charger.
What shortens car battery life? ›
Factors that can shorten its life include an extended period of partial or full discharge, vibration from not being properly secured, under- or overcharging, extreme temperatures, water loss, electrolyte contamination and corrosion on terminals.
How long can a battery sit in a car before it dies? ›A car battery can last 3-4 weeks maximum when left idle before it dies. So, it's essential to start the car at least once a week to keep its charge. Routinely maintaining your battery by cleaning the corroded terminals and topping up its electrolyte will improve battery life.
How long can a car battery sit unused? ›If you know your car battery is relatively new and has been kept in good condition, it can probably sit unused for about two weeks before it goes flat. If you've left your car unused for over two weeks, it's quite likely you'll need professional assistance.
How long does it take to charge a 12 volt battery at 10 amps? ›Step 3: Charge the battery at a 10-amp rate. Take the amount of amp-hours needed by the battery and divide it by 10 amps. Using the example above, it would take around 4.5 hours to recharge that battery. (The best charger to use to charge a car battery is a 3-stage automatic 12 volt/10 amp charger.)
How long can you leave a 2 amp charger on a battery? ›How long to charge a battery at 2 amps? It takes 24 hours to fully charge a 48 amp battery at 2 amps. A battery has around 48 amps, so divide 48 by 2 and you arrive at 24 hours.
How long does it take to charge a car battery at 6 amps 12 volts? ›However, as a general rule of thumb, it would take approximately 8-16 hours to charge a completely drained car battery at 6Amps.
Why is my car battery draining so fast? ›“Electrical devices or lights left running, a defective charging system or alternator, and extreme weather are some common reasons but maybe it's just time to get a new battery.”
How long should you leave your car running to charge the battery? ›How long should you leave the car running after a jump? It's best to drive the car around or let it idle for at least 30 minutes after you jump-start it. Ideally, you should drive the car around for 30 minutes to allow the alternator to charge the battery to a good level.
How do you revive a dead car battery with baking soda? ›Cleaning Battery Corrosion with Baking Soda and Water
Apply baking soda over the entire area that's affected by corrosion. This will neutralize the battery acid. Add a small amount of water to activate the baking soda and cause a chemical reaction which will remove the corrosion.
A: If you leave the charger connected continuously, even at a mere 2 amps, the battery eventually will die. Overcharging a battery causes excessive gassing — the electrolyte gets hot and both hydrogen and oxygen gas are generated.
How long can you leave a car battery on a trickle charger? ›
A trickle charger can take up to 48 hours to charge a battery to full capacity as most only use one to two amps of power. You can even leave some smarter trickle chargers for days or weeks at a time, but it's best to check with the manufacturer if this is suitable.
Is it OK to leave a battery maintainer on all the time? ›So, can you really leave your battery maintainer on all the time? Fortunately, the answer is yes! Battery maintainers are designed for constant and long-term use. When used correctly, they should be perfectly safe to use as long as you need.
How long can you leave a battery maintainer on a battery? ›Is It Okay to Leave a Battery Maintainer On All the Time? Unlike standard and trickle chargers, a battery maintainer can be attached to a battery indefinitely without any fear of overcharging. This makes them perfect for seasonal vehicles that will remain idle for longer periods of time.
What is the difference between a car battery charger and a trickle charger? ›Regular battery chargers are designed to deliver higher constant voltage to the battery charging it much faster, however the trickle chargers deliver a slow charge to your battery and are designed to be left on your battery for extended periods of time.
What are the two types of battery chargers? ›The two most common types we offer are manual battery chargers and automatic battery chargers. These two charger types have key differences in their operation.
How long to charge a completely dead battery with battery charger? ›A normal-sized car battery can be fully charged in 2 to 4 hours with a 20 Amp charger, and with a 4Amp charger, it takes around 12 to 24 hours. You can also jumpstart your car's battery using another vehicle. If you can get it started, idling is also an option for charging the battery.
Can you charge a completely dead battery with a trickle charger? ›Yes, a trickle charger can fully charge a battery; it will just take a very long time. Because trickle chargers only emit between 1-3 amps, you can expect to wait days for a fully charged battery. For example, a 1-amp trickle charger will take a full 100 hours to completely charge a dead Battle Born 100 ah Battery.
How long does it take to charge a dead battery with a battery charger? ›“A deeply discharged battery, given 15 to 30 minutes on a 40-amp charger, should be able to start the car, giving the alternator a chance to finish charging the battery," said Jerew. "But you should never charge at such a high rate longer than this.
What happens if you leave a battery charger on a car battery for too long? ›A: If you leave the charger connected continuously, even at a mere 2 amps, the battery eventually will die. Overcharging a battery causes excessive gassing — the electrolyte gets hot and both hydrogen and oxygen gas are generated.
How long does it take to charge a completely dead 12v battery? ›How long does it take to charge a car battery with a 12 volt charger? Car batteries usually hold 48 amps, so it will take about 12 hours to reach a full charge using a 12 volt charger.
Should I charge my car battery at 2 amps or 10 amps? ›
You would use 10 amperes on a car battery and 2 ampere on whatever small batteries you might want to charge that still use the same voltage. For example, a motorcycle battery could use the 2 ampere charging option.
Can you leave a car battery charger on overnight? ›Even though there is no risk of overcharging with the use of a high quality charger, the battery should not remain connected to the charger for more than 24 hours.
Should I disconnect car battery before charging? ›Q: Should I disconnect a car battery before charging? A: It isn't necessary to disconnect a battery before charging. Any drain while the car is turned off will be minimal. The charger's voltage won't be high enough to do any damage to the car.
How often should you trickle charge a car battery? ›Here's what we do know. Most batteries are not fully-charged when vehicles are parked. In fact, we recommend connecting your car battery to a quality battery charger once a month, just to make sure your battery does get fully-charged.
Does idling a car charge the battery? ›Do Car Batteries Charge While Idling? A car with an idling engine will still recharge your battery, but at a much lower rate than if you were driving. The reason for this is that modern cars have a lot of additional electronics that use up power.
How long does it take to charge a car battery with a 10 amp charger? ›Take the amount of amp-hours needed by the battery and divide it by 10 amps. Using the example above, it would take around 4.5 hours to recharge that battery. (The best charger to use to charge a car battery is a 3-stage automatic 12 volt/10 amp charger.)