Delivers 10-amp output. Works with many batteries, including autos, jet skis and generators. Automatic operation. Thermal sensor detects ambient temp and adapts to eliminate over-charging/under-charging in extreme weather. Charges batteries as low as 1 volt.
Pricey. All the features can be daunting to new users.
Able to resurrect batteries that have drained to as low as 1 volt. Built-in thermal sensor prevents overcharging in hot climates and undercharging in cold climates. Auto charging feature lets you keep battery connected indefinitely without fear of overcharging.
This 1-amp unit may take up to two days to charge a 12-volt battery.
This unit can fully charge a 12-volt battery in under 12 hours. It has an 8-step charging program that can revive, charge, and maintain voltage levels. Safety measures include spark resistance, reverse polarity protection, and being short circuit-proof.
The price is a bit steep, but this charger is fantastic.
With 1.5-amp output, you'll be able to charge your batteries fast. Charger is waterproof, making it great for working in wet weather. Protects the battery during charging. Ships with both alligator clips and ring connectors to match your battery.
Some report failure of unit after only a few uses.
Works with any 12-volt battery. Just connect the solar charger to your battery, and it will deliver power anywhere, even when you're nowhere near a power outlet. Ships with a cigarette lighter port adapter and alligator clips.
Lacks ring connectors. Higher price point than many.
We recommend these products based on an intensive research process that's designed to cut through the noise and find the top products in this space. Guided by experts, we spend hours looking into the factors that matter, to bring you these selections.
Most people don’t realize that the battery in a car is constantly draining, even when the vehicle isn’t being used. If a car is placed in storage, the battery will be dead in as little as a month or two. That's when a trickle charger comes in handy.
A trickle charger delivers a slow and steady charge to keep the battery operating at its peak. However, you must take care not to overcharge the battery because overcharging will damage it. The best trickle chargers are designed to eliminate the possibility of overcharging.
There are two main areas to consider when shopping for a trickle charger. You need to know the type of battery or batteries you’ll be charging (for example, car, motorcycle, snowmobile, marine, 12 volt, 6 volt) and how quickly you want your charger to work.
In most instances, you’ll need a trickle charger that’s designed for a 12-volt lead-acid battery. This is the type of battery that’s normally used in automobiles. However, that isn’t the only type of battery that could benefit from a trickle charger. If you have a different type of battery in your snowmobile or motorcycle, for instance, you'll want to purchase a trickle charger that’s designed to accommodate all of your battery charging needs.
The average trickle charger is designed to work slowly because it’s safer to charge a battery slowly. The greater the number of amps, the faster the unit will charge. Most models are 2 amp. Some higher-end models boast a 3-amp or 4-amp charging speed. For more information on amps, see the FAQ section below.
Trickle chargers have a number of features that are designed to make them safer and easier to use. Unfortunately, these features can vary greatly from model to model, so you'll have to do your research to make sure the one you're considering has all the features you desire.
Overcharge protection: Trickle chargers feed a slow and steady charge to a battery, but even a glass that’s filled one drop at a time can overflow. To protect your battery, look for a model that has some type of overcharge protection or tender mode. If you don't, you'll need to keep an eye on the charging process and manually shut off the unit when it's done. This isn't hard, but if the battery has been charging for 18 hours, it's a task that’s easy to forget.
Besides overcharge protection, some trickle chargers feature modes that are unique to the model. Since the modes can vary from model to model, look for a charger that features modes that match your needs.
Recovery: One example is a recovery mode. This allows you to essentially bring a battery back to life after it has been discharged beyond typical levels.
Lithium-ion: Other models have modes that make it possible to charge a lithium-ion battery as well as a lead-acid battery.
Trickle chargers are not "smart" in the way that home appliances are smart. They currently don't connect to your phone and allow remote access. When a trickle charger is labelled as smart, it means that the device has fail-safe features built in to monitor such items as charge level, temperature, and other critical factors. A model that isn't considered smart just means that it's fully manual.
On the higher end of the price scale, you can purchase a trickle charger that does more than charge. Once connected to your system, these models can diagnose and check other components in your vehicle, such as your alternator, to be sure a low battery charge is really what your problem is.
Reverse polarity: If you connect your charger incorrectly and turn it on, you run the risk of damaging the charger, the battery, and any components that are connected to your vehicle's electrical system. Reverse polarity protection prevents your trickle charger from operating if it isn't properly connected to your battery.
Spark: Sparks can be dangerous. Beyond a shock hazard, sparks around a car battery could cause gases to combust. Some models have built-in technology to reduce or eliminate sparking that may occur when connecting the leads from the charger to the battery.
The more information that's available at a glance, the more safely you can operate your trickle charger. Indicator lights can tell you when the unit is on, what operating mode it's in, the level of charge in the battery, and if there are any problems with the charger or the battery.
Most trickle chargers have a compact design, so size isn't a huge factor. However, some of the higher-end models — the ones that offer greater versatility — can be a bit larger. If you're looking for something small that will fit in the trunk or even the glove compartment yet still offer advanced features, that option is available, but it will cost considerably more than a basic trickle charger.
A trickle charger should only be used in areas with adequate ventilation that also provides shelter from the elements. Some individuals may not have a carport or garage that's readily accessible for their needs. They should seek a water-resistant trickle charger that's designed to operate in more extreme temperatures.
Not all battery terminals are the same. While alligator clips are remarkably versatile and allow you to connect to a wide variety of batteries, sometimes, such as when you need to charge a motorcycle battery, they’re just too large to fit. In that instance, you need a charger that also includes ring terminals.
To get the longest life from your car battery, always start your vehicle with all the accessories off.
Inexpensive: In the $10 to $20 range, you’ll find basic trickle chargers. These will do the job, but they’ll probably only do it on one type of battery and only have one or two indicator lights.
Mid-range: From $20 to $50, you can get a trickle charger with a battery tender that works on both 6-volt and 12-volt batteries. These models also typically offer a wider array of indicator lights.
Expensive: If you move up into the $50 to $100 range, you'll find trickle chargers with a variety of bells and whistles. These units may feature advanced diagnostics, more detailed status indicators, and even jump-start capabilities.
If you've never used a trickle charger before, you might be a little unsure of how to operate one. The following is a short list of steps to help you.
A. This varies from car to car and from battery to battery. A good rule of thumb is a maximum of two months. If you have an older battery or a car with a lot of devices that drain the battery — even when the car isn't running — you may only get one month. That's why it's very important to put your car, motorcycle, or boat battery on a trickle charger if it won’t be used for an extended period of time. It's possible for a battery to get so drained that it can’t be started, even after a charge.
A. In layman's terms, amps simply relate to how fast electricity is flowing. If you want to get technical, 1 amp means that 6.24 quintillion electrons are flowing past a single point every second. Most trickle chargers are 2-amp chargers.
A. Trickle chargers don't charge very quickly. It can take up to 24 hours for a 2-amp trickle charger to charge a 12-volt car battery.
A. The answer to this varies depending on the features found on your trickle charger. A basic one may not shut off after your battery is fully charged, so you run the risk of overcharging your battery. Thoroughly read the owner's manual and understand the features your model has before attempting any type of long-term charging.
A. In the best-case scenario, an overcharged battery just dies and becomes unusable. In the worst-case scenario, gases build up from the boiling fluid inside, and then swelling, leaking, or even bursting become possibilities.