See here the list of Top 10 best car battery chargers. Read the buying guide and other important factors before making a selection for you or any of your dear ones

SaleBestseller No. 1
Schumacher SC1281 6/12V Fully Automatic Battery Charger and 30/100A Engine Starter with Advanced...
  • Features 30A quick boost and 100A jump start, powerful enough to start SUVs, trucks and large batteries
  • Battery and alternator tester provides charge level and helps diagnose electrical problems
  • Features multi-stage charging and auto-voltage detection for added precision, safety and battery life. UL Safety Certifications
SaleBestseller No. 2
Battery Tender 12 Volt Junior Automatic Battery Charger
  • Spark proof during lead connection, reverse polarity protected and includes a 12-foot output cord and 5-year warranty
  • Perfect for charging all 12-volt lead-acid, flooded or sealed maintenance free batteries (AGM and gel cell) and safety timer-80 hours
  • Complete 4-step charging program (Initialization, Bulk Charge, Float Mode) allows for optimization of battery power, without overcharging
Bestseller No. 3
DieHard 71219 6/12V Shelf Smart Battery Charger and 2A Maintainer
  • Micro processor controlled, fully automatic, 5-stage charging process for precise charging and monitoring batteries
  • LED indictor will flash if clamps are reversed and charger will not operate
  • Features battery maintaining to prevent overcharging, charging will resume if battery becomes discharged
SaleBestseller No. 4
NOCO Genius G3500 6V/12V 3.5 Amp Battery Charger and Maintainer
  • The most versatile all-in-one battery charger any vehicle owner would need to quickly recharge its battery in hours, including cars, boats, trucks, RVs, tractors and much more up to 120 amp-hours.
  • Perfect for keeping your vehicles fully-charged and maintained during year-round battery maintenance or long-term storage for improved performance and longevity.
  • Works with all types of 6-volt and 12-volt lead-acid batteries, including Wet, Gel, and AGM, or any common automotive, deep-cycle, marine, or maintenance-free battery.
Bestseller No. 5
Schumacher SC1280 6/12V Rapid Battery Charger and 15A Maintainer
  • Features 15A to charge and 3A to maintain your battery
  • Auto voltage detection automatically detects 6 or 12V batteries
  • Automatically selects charge rate for charging and maintaining
Bestseller No. 6
BMK 12V 5A Smart Battery Charger Portable Battery Maintainer with Detachable Alligator Rings Clips...
  • 【UPGRADED DEFECTIVE BATTERY DETECT/FAST CHARGING CAR BATTERY BOOSTER】Updated with battery condition diagnose to detect the defective battery before charge. DC Output 13.8V/5A, AC Input 100-240V,...
  • 【UPGRADED 72-HOUR SAFETY FEATURES/MULTI SAFETY PROTECTIONS - BATTERY RESCUE & RECOVER】Updated with 72 hours safety feature to commence anytime the charger is onto protect marginal batteries from...
  • 【4-STAGE SMART CHARGING - FULLY AUTOMATIC BOAT BATTERY CHARGER】 12V battery charger operated with 4 stages automatic charging process by MCU controller, 25%/50%/75%/100% to indicate quantity of...
Bestseller No. 7
BEATIT QDSP 800A Peak 12V Portable Car Lithium Jump Starter (up to 7.2L Gas or 5.5L Diesel Engine)...
  • BEATIT B10 PRO is the most compact portable size and light weight with heavy duty feeling construction for emergency car jump starter.
  • With a peak of 800 Amps (UL2743 Certified) - it's able to jump start flat batteries up to 20 times on a single charge. Work with all 12V battery cars, vans, trucks, motorcycles, snowmobiles, ATV, UTV,...
  • 12,800mAh power bank designed with dual USB output(5V/2.1A) 10W and type C port(5V/3A) which is both in and out, used to recharge this charger and also to charge your USB devices, battery standby time...
Bestseller No. 8
NOCO Genius G7200 12V/24V 7.2 Amp Battery Charger and Maintainer
  • The most versatile all-in-one battery charger any vehicle owner would need to quickly recharge its battery in hours, including cars, boats, trucks, RVs, tractors and much more up to 230 amp-hours.
  • Perfect for keeping your vehicles fully-charged and maintained during year-round battery maintenance or long-term storage for improved performance and longevity.
  • Works with all types of 12-volt and 24-volt lead-acid batteries, including Wet, Gel, and AGM, or any common automotive, deep-cycle, marine, or maintenance-free battery.
SaleBestseller No. 9
DEWALT 12V/20V MAX Car Battery Charger (DCB119)
  • Charges all DEWALT 12V and 20V MAX Li-Ion batteries from a vehicle's power outlet
  • Enables batteries to be charged while driving to work or on a job site
  • Charges the battery in 1 hour or less, minimizing downtime
Bestseller No. 10
5 Amp 12V Automotive Smart Battery Charger/Maintainer for Car, Motorcycle, Lawn Mower, Boat, RV,...
  • 5 amp battery charger maintains and charges all type of AGM, GEL, SLA, Flooded(WET), Calcium type deep cycle automotive or marine 4Ah-100Ah 12V battery.
  • Fully automatic high frequency charging delivers 3 stage charging, automatically switching from fast charge, to top-off, then to trickle charge.
  • Built in circuit protection guards against against reverse polarity, sparks, overcharging, over-current, open-circuits, short-circuits and overheating.

The nightmare of every car driver: a cold winter morning, the car may have just been laboriously cleared of snow and ice, but turning the ignition key causes nothing more than a tormented slow turn of the starter – the engine does not start. It does not look any better if a power-consuming device is turned on accidentally overnight and the radio or interior lighting consume the battery power indispensable for starting. Chargers for car batteries promise remedy and prevention. An overview of the fundamentals of technology, central features of common models and well-known manufacturers, forms the basis of a long-term satisfactory purchase decision.

1. Technology

Strictly speaking, the so-called car batteries are not batteries in the classical sense, but accumulators, ie charge storage with the possibility of recharging. The term car battery has prevailed, however. Actually, there is no need to recharge a car battery. Car batteries are pre-charged sold and charged while driving, by electricity generated by the alternator. For an average life of five years, commercially available starter batteries should ensure such a smooth start.

Under certain conditions, such as the more common short-haul trips, however, it is not possible to generate enough charging current to compensate for the daily consumption, resulting in a long-term discharge. If the car battery has fallen below a minimum charge level, the voltage is no longer sufficient to cover the high demand for starting – the vehicle does not start.

Especially in the cold winter months, the risk of a critical discharge increases. Due to the cold, the capacity of the car battery is reduced because chemical reactions in the interior are slowed down. Specifically, a car battery at -10 ° Celsius has only two-thirds, at -22 ° even only about half of their nominal capacity. At the same time increases by cold, associated increased friction, viscous engine oil and a worse combustion and by winter usual additional consumers of the voltage requirement, which even a partial discharge can cause problems when starting the vehicle.

2. Battery types

Car batteries can basically be distinguished on the basis of their design and their technical specifications. Common variants are batteries with a rated voltage of 6 volts, for use in motorcycles, 12 volts in normal cars and 24 volts rated in trucks. Furthermore, one differentiates according to the capacity of a battery, which is indicated in ampere-hours (Ah). Small starter batteries used in motorcycles have, for example, over 4 Ah, cars usually, according to vehicle size and motorization between 36 and 64 Ah, and trucks have correspondingly powerful batteries, with 200 and more amp hours.

3. Starter batteries are usually lead-acid batteries.

According to their construction, one differentiates

– Wet batteries or flooded batteries, the most common type of car battery, with electrodes made of lead-antimony alloy in dilute sulfuric acid

– Calcium batteries, which are similar to the wet batteries, but as electrodes are used plates made of a calcium alloy

– AGM (absorbent glass mats) Batteries also called dry batteries, as the most modern variant, in which the sulfuric acid is bound in glass fiber fleece

– GEL batteries in which the sulfuric acid is converted into a gel by the addition of silica

Another basic distinguishing criterion relevant to maintenance is the division into open and closed automotive batteries. Open car batteries are usually provided with screw-top closures, which allow access to the individual battery cells (each two volts nominal voltage resulting from a battery cell, a normal car battery with 12 volts is thus made of six separate cells). These cells are filled with dilute sulfuric acid, the so-called electrolyte and must be checked with open car batteries, before filling to fill level and optionally filled with distilled water.

The second variant are closed car batteries, also called maintenance-free. With them, the opening of the battery cells is not provided and refilling is not necessary. They only have a pressure valve, which allows gas to escape when overcharged. However, all types of car batteries have the described discharge characteristics, although they are subject to varying degrees.

4. Characteristics

Lack of recharge by short trips, Increased consumption by low temperatures, discharge by accidentally activated consumers for a long time in stand or even simple self-discharge by long service life, which always cause the failure of the battery, an exchange is not always mandatory. In any case, a recharge that is possible in the majority of cases is cost and environmentally friendly.

The trade offers a variety of suitable chargers, all promise to be up to the task to be optimally, yet a comparison makes sense and even necessary in some areas. Even when it comes to the basic function of recharging, there are sometimes significant differences between individual models.

4.1. Fitness

In principle, all named and common types of car batteries can be charged with standard car battery chargers, without having to pay particular attention to the battery type. Only in conjunction with GEL batteries should you check in advance with the help of the operating instructions of the charger, if it is suitable for charging them.

4.2. Fast Chargers

The idea of ​​shortening the time required to recharge a discharged car battery by using a charger with the highest possible charging current seems obvious. Nevertheless, it is generally discouraged by so-called rapid chargers, which use just this principle, since they can lead to a shortening of the life of a car battery by so-called lattice corrossion on the one hand. In this case, the electrodes made of lead compounds disintegrate, which in the medium term can lead to the failure of individual battery cells and thus to the irreparable defect of the battery.

A quick charge of a car battery is used when the charging current is up to one third of the rated capacity of the battery. However, it is advisable to use a slower charge with at most one tenth of the capacity. Under no circumstances, however, when charging a 12 volt car battery, the applied voltage should exceed 14.4 volts. However, to allow a charge, it must also not be less than 13.8 volts.

4.3. Smart Chargers

Especially for motorists who are less interested in technical issues and still do not want to dispense with the independent reloading of a car battery, offer so-called intelligent, microprocessor-controlled charging devices. These devices not only recognize with a battery of what nominal voltage they are dealing, they also adapt the entire charging process to the connected battery. The charge level is measured and the optimal charging current is given out at all times until the car battery is fully charged.

4.4. Designs

For many years, the usual form of professional workshop equipment is the design of a good shoe-box-sized sheet steel housing, with a carrying handle on the top and analog scales on the front. Often here the choice of charging voltage and a selection of the charging current still manually by rotary control. As well as visually and practically contemporary variant are also devices with plastic housing in the form of a portable radio. Both versions are equipped with power supply and charging cables with a higher cable average and are usually equipped with large, completely plastic-coated pole tongs.

Especially for non-commercial, private use, however, decidedly handier devices have prevailed in recent years. The plastic cases are usually a little larger than a pack of cigarettes and inform the user by means of an LED display about the current charging process. Cables and pliers are usually much smaller dimensions. Most of them are microprocessor-controlled devices that completely dispense with setting options.

4.5. Battery care

The field of application of a modern battery charger goes beyond the mere recharging of a discharged car battery significantly. A car battery is exposed to natural wear in addition to the aforementioned extreme stresses, which significantly affects their lifespan. Therefore, battery care and battery maintenance are important additional features that make a meaningful car battery charger.

4.6. Sulfation

The term sulfation describes a natural chemical process that also happens inside a car battery. The chemical processes which form the basis for the provision of the necessary electrical current lead at the same time to an accumulation of lead sulfate crystals on the electrodes. This leads to reduced conductivity. In addition, these crystals can dissolve by vibration, which can lead to the so-called silting of the battery cells – the long-term accumulation of crystals at the bottom of the cell.

Collecting these crystals up to the height of the electrodes can lead to a short circuit in the worst case. Sulfation occurs especially when a battery is not in use for a long time, ie no currents are flowing. This is always the case, for example, when a vehicle is not moved for a long time, as is the case, for example, with vintage cars or seasonal vehicles.

4.7. Desulfation

The reversal of the process described is called desulfation. Under normal circumstances, with regular discharge and charging of the car battery in daily operation, the described lead sulfate crystals are dissolved. If this is not the case, the described accumulation of crystals on the electrodes and in the cells of the battery occurs. Here a desulfation by a suitable car battery charger can improve the condition of the car battery.

The best means of doing this is theoretically an over-voltage charge, so charging the battery with increased voltage. However, this would contribute to the aforementioned lattice corrosion and damage the car battery irreparably. The solution to this problem is extremely short surge charge current pulses. At an optimum frequency, the voltage delivered by the charger is increased for a few microseconds, which leads to a resolution of the crystals, without damaging the battery at the same time.

4.8. Trickle charging

Whether motorhome, second car, classic car or just little used vehicle, long service life lead to a discharge of the car battery and can damage them as described. To prevent this, it is recommended to charge an unused car battery during its lifetime. However, a permanent connection to charging current would lead to overcharging and thus to damage to the battery and in the worst case to the risk of explosion due to gas formation.

Therefore, modern car battery chargers have a function of the so-called trickle charge, also called pulse conservation. When maintaining the pulse, the charger measures the charge of the connected car battery. If it falls below a threshold (usually 95% of the total capacity) the charging process is activated. When the battery is fully charged, the device automatically shuts off. This process counteracts the self-discharge, keeps the battery permanently ready for use and prevents damage by sulfation.

4.9. Safety

In addition to monitoring the battery temperature during trickle charging, good battery charger have additional safety features that prevent user exposure and damage to the battery or charger. These include, above all, a short-circuit protection, often realized in repair shop equipment by a simple plug fuse and a reverse polarity protection, which draws attention with most devices by optical signal on it, if plus and minus pole of the battery and charger were not mismatched.

5. Manufacturer

Battery chargers are sold by specialty retailers, car dealers, DIY stores, and occasionally even well-known food discounters. The number of available models is large, as well as those of the manufacturers, of which, however, only a few are known by name.

5.1. Einhell

As a well-known supplier of a comprehensive range of power tools, Einhell is one of the long-known manufacturers of classic car battery chargers. Above all, the design of the workshop charger is on offer, which is moving in the lower and middle price segment.

5.2. CTEK

The Swedish company CTEK SWEDEN AB is internationally known for the development and production of chargers for all types of vehicle batteries. The quality of the devices has been repeatedly confirmed by independent tests. Chargers are available for private and professional use, in a small design. Depending on the range of functions and field of application, the devices of CTEK are in the middle and upper price segment.

5.3. Cartrend

Cartrend is a brand of SPA SystemPartner GmbH & Co. KG, founded in 1998. As a complete supplier of car accessories, car battery chargers are distributed via the Internet and retail. Also in the seasonal offer of individual discounters are occasionally models of Cartrend. The microprocessor-controlled devices are offered in the lower and middle price segment.