The 8 Best Trickle Chargers
This wiki has been updated 27 times since it was first published in December of 2016. Whether you need to coax a dead car battery back to life or want to keep your garage-stored motorcycle ready for action over the long winter, trickle chargers are an important part of at-home vehicle maintenance. Our list includes a wide range of options for use on just about any machine out there, from large trucks and construction equipment to ride-on lawn mowers and golf carts. When users buy our independently chosen editorial recommendations, we may earn commissions to help fund the Wiki.
February 03, 2021:
While we removed the Aurelio Tech Transportable Charger due to availability issues, we also replaced Noco Genius G750 with a logical successor from the company’s new line: the Noco Genius10. In addition to the older model appearing to be discontinued, we liked the way the new generation packed more than double the power into a significantly smaller housing.
Our other new additions this time around include the Black & Decker BC25BD — which we ranked lower than the Black & Decker BC6BDW, even though the BC25BD is much more powerful, because we like the portability and weatherproofing offered by the BC6BDW (both qualities being prime assets for this category, in my view); and the CTEK MXS 5.0 — an affordable, compact model that you can probably get away with stashing in your center console, but still packs a few useful features, like battery-reconditioning and -diagnosis functions.
Trickle chargers are great – if you’ve got room to keep one setup in your shop or garage, or if you find yourself in a bind – but if you can’t stand bothering with them, then a solar battery maintainer might be a good idea for you.
June 21, 2019:
For the most part, our selection of best trickle chargers for 2019 matches that from 2018 -- with a few important exceptions. For one thing, we added the Foval 1000mA at #9, primarily because of its ergonomic size and 4-stage programming, but also because of its rock-bottom price tag. For another, we bumped the Black & Decker Waterproof up to #2, in part because its rugged design promises to make it one of the longest-lasting investments on this list. And finally, we moved the Battery Tender Plus to #1 -- the fully-automated unit is both powerful and versatile enough for it to maintain all kinds of vehicles, from small motorcycles to large trucks.
What Is A Trickle Charger?
Whereas most trickle chargers put out between one and three amps, car battery chargers can pump up to 50 amps in charge mode.
Whether you own a car, a motorcycle, an ATV, or a boat, at one point or another you've likely been faced with the conundrum of a dead or depleted battery. And you probably dealt with it the way most people do, by jump-starting it or hooking it up to a car battery charger. But there's a better solution, especially when it comes to caring for those smaller, more sensitive recreational vehicles: use a trickle charger.
Simply put, a trickle charger is a battery charger that consistently emits a very low amperage. Most trickle chargers consist of a simple plastic or metal box in which the wires and main electrical components reside, a power cable, and two alligator clips. Also known as battery maintainers, these devices are designed to connect to a battery for a long period of time, slowly bringing it back up to health without overcharging. Some can be left on indefinitely, preventing the battery from losing charge and naturally depleting itself during storage or in between uses.
A trickle charger, then, is not a regular automotive battery charger, which is capable of recharging a drained battery in just minutes. Whereas most trickle chargers put out between one and three amps, car battery chargers can pump up to 50 amps in charge mode. Some also have jump-start functions, which can produce upwards of 200 amps in order to turn over a motor.
Of course, trickle chargers and automotive chargers aren't mutually exclusive — some products out there will do the work of both, incorporating low amp outputs and jump-start functions for all sorts of scenarios.
Why Use A Trickle Charger?
As previously noted, trickle chargers emit a low amperage to slowly charge a battery over a long period of time. To use a somewhat stale metaphor, if traditional car chargers are like the hare in Aesop's Fable, trickle chargers are the tortoise — slow and steady wins the race.
Battery chargers reverse this process, turning the lead sulfate back into lead, and releasing the electrolyte back into the solution and making it more acidic.
To see why this method can be beneficial when it comes to charging your battery, it's useful to understand a little about the science of batteries themselves. Conventional lead-acid batteries convert chemical energy into electrical energy through a series of lead plates submerged in an electrolyte solution of sulfuric acid: when charging or discharging, ions, or atoms with a positive or negative charge, react with the electrolyte and the electrodes to create electrons, which transfer through an external circuit to create an electrical current.
As the battery discharges, these parts undergo chemical changes — the acid degrades into water, and the lead plates become coated with lead sulfate, which eventually causes the battery to go dead. Battery chargers reverse this process, turning the lead sulfate back into lead, and releasing the electrolyte back into the solution and making it more acidic. But doing it too fast can have costs: excess amperage can generate lots of heat, which can result in dangerous and harmful out-gassing. You're also more likely to overcharge your battery with a regular battery charger, which can result in further damage.
Trickle chargers avoid some of these negative effects, primarily by slowing down the process and reducing the chances of overheating and overcharging. That makes them especially handy for use on smaller capacity batteries, such as those on motorcycles and ATVs, for which automotive chargers can be too powerful. They're also great when you have a battery that might not be getting regular use, such as those on boats or vintage cars, since the low current will help keep its charge stable as the battery self-discharges overtime.
Whatever kind of battery you use it on, a trickle charger can help keep your battery healthy and ensure you get the most out of its life cycle.
Types Of Trickle Chargers
Deciding a trickle charger is right for you is actually only the first step toward finding and ultimately investing in one. That's because trickle chargers don't come in one standard form — there is a range of types out there, all differing from one another in terms of power and features.
For that user whose garage is home to more than one type of vehicle, this may be the best option.
Manual trickle chargers are among the most affordable options on the market, and also offer the user a degree of control over the charging process. They're ideal for those instances when you need to restore a dead battery to full health, since they'll provide a slow current that won't cause overheating. Just remember to take the device off the battery once fully charged, since these models don't have any automatic shutoff functionality and could damage the battery if left on too long.
Automatic and smart chargers are a little more high-tech, incorporating float or auto shut-off modes to keep the device from overcharging the battery. These are useful when you have to maintain the charge of a battery in storage, since they're able to monitor and adjust their current based on the battery's power level — all you have to do is plug it in and let it do the work for you.
There are also models that combine both of the aforementioned functions, capable of both bringing a battery to full charge and also maintaining it over a long winter. Many battery tenders embody this kind of hybridization, featuring multi-step charging programs that will quickly revive a battery and then float it for an indefinite period of time. For that user whose garage is home to more than one type of vehicle, this may be the best option.