If your car battery is beginning to drain, or you don't drive your car very often then the best battery charger for your needs will be a trickle charger. Also called a battery maintainer, these simple tools will prevent it from discharging over a long period of time. Whether you're storing a car away for winter, having a busy schedule, or otherwise, a trickle charger can come in very handy.
Anything with a battery will lose charge over time, from a car to your mobile phone. This is especially true during winter as batteries don't cope so well in the cold weather. A trickle charger works by drawing a tiny current of electricity to keep the battery topped up but will work to ensure the battery isn't overcharged.
If you walk around a premium/specialist car dealer, you will notice that a lot of the stock have trickle chargers connected. Because a Porsche Carrera GT tends to sit around in a dealer for longer than a Golf GTI, the need for a trickle charger is clear. This inherently reduces the need for a car jump starter if it's been sat for too long.
The best trickle chargers at a glance:
Editor's pick: NOCO Genius10 - Buy from Amazon.
Best solar trickle charger: CTEK Portable Battery Charger Maintainer - Buy from Amazon.
Best quality trickle charger: CTEK MXS 5.0 - Buy from Amazon.
Available as either plug-in or solar-powered, simple or smart battery chargers, some even work as slow jump starters. We've examined the best trickle chargers on the market, examining price, size, purpose and extra features to select the best. We've chosen our favourites at a range of prices so you can find one that suits your needs.
The best trickle chargers
Editor's pick
Via NOCOThe big daddy of car battery maintenance, there's not much a good NOCO can't do to revive, charge and care for a car battery. The GENIUS10UK is a compact choice that packs a serious punch. Working as an advanced trickle charger, it'll keep your battery as healthy as possible and worry-free. If that's not enough it can also charge dead batteries, restore lost battery performance and work with both 6 and 12V batteries.
Pros
- Last name in battery protection
- Top-notch quality
Cons
- Overkill for city cars
We've tested the MXS 5.0 and found it to be not only very nice to hold thanks to its premium materials, but a very useful trickle charger that's easy to connect and set the modes on. It also held up to the cold snaps in December and January very well, not indicating a single fault in its operation.
During bi-weekly stints, it did its thing and kept a great amount of charge in my car's battery. But our criticisms extent to the sheer cost of CTEK's optional extras that can be paired with the MXS range. This includes things like the extension cable, spare crocodile clamps, and the rubber protective cover.
Pros
- Great quality materials
- Very clever charger
Cons
- Add-ons aren't cheap
Best budget solar trickle charger
Best budget solar trickle charger
Via AASolar charging is a clever option for keeping a car charged up anywhere outside. So long as the panel is in direct sunlight (and connected to your car's battery) it'll charge your car up. It's the perfect option for cars that sit idle for long periods of time outside. Be warned, however, it won't help dead, damaged or fully discharged batteries.
Pros
- Harnesses the sun
- Good quality
Cons
- No good on dead batteries
Best comprehensive quality trickle charger
Via CTEKA stage above the MXS 5.0 is the 7.0. It can also supply power and sympathetically condition your car's battery to a healthy level and prevent it from losing charge.
It's a bit thicker than the 5.0, and it boasts slightly more comprehensive battery condition modes, including a cold weather mode. This allows the charger to perform at its best during harsh, very cold temperatures.
Pros
- Fantastic quality materials
- Great charging and conditioning power
Cons
- Has the same issues as the MXS 5.0
Best trickle charger on a tight budget
Best budget trickle charger
Via Clarkewww.machinemart.co.uk
A very simple way to keep your charge up - plug it into a standard three-pin socket and connect the cables to your car's battery. The Clarke Auto Trickle Charger is designed for 12V lead-acid batteries and is manufactured to be protected against short-circuiting, reverse polarity and overloads.
Pros
- Good value
- Simple to use
Cons
- No good on dead batteries
Best trickle charger for style
Best solar powered trickle charger
Via CTEKThe simple-to-use and good-looking option from CTEK, this portable battery maintainer will hold its charge for a full year giving plenty of peace of mind. Like the NOCO it can be used to restart dead batteries, too, using Adaptive Boost technology to restart a dead battery in the safest way possible. You can even buy a solar panel attachment for solar trickle charging.
Pros
- Clever design
- Helps keep the battery safe
Cons
- The solar panel attachment is additional
What you need to know about trickle chargers
Why is my battery going flat?
There are a lot of factors in why batteries go flat. the most obvious is that as batteries get older, they lose efficiency and, as such, will discharge quicker. Modern cars also feature a lot of electronics (think computers, alarms. central locking and even the clock) which will eat up a battery charge if you leave the car alone for long enough. Even a comprehensive solar battery charger won't be able to rescue a car battery that's degraded as a result of a very long wait.
Most cars use old-fashioned lead-acid batteries that love to discharge themselves over time. Leaving an interior light on or a dashcam hardwired can also speed up the discharging process. Cold weather can also be a factor in flat batteries. Batteries need a comfortable temperature to work effectively, and when it gets frosty, you may notice they lose charge quicker. This is one of the reasons why it's healthy to run your car's engine every now and if you're not using it, even a budget battery charger will do the job.
Do I need a new battery?
If your battery is going flat in an unacceptably short amount of time and even a trickle charge isn't keeping it working properly, then it's probably time to invest in a new car battery. One of the easiest ways to notice an indicator is if the trickle charger is constantly displaying a half-charge or less. CTEK chargers for example will consistently display an orange light for a while, which is a sign that battery has seen its last days. Modern car features such as stop-start and all the other gismos requires even more power from a car battery. We've even created the best car batteries for stop-start equipped vehicles, if you're in need of a new one.
Ryan Gilmore is the Deputy Autos and Tools Editor for CAR, specialising in car cleaning and hand tools. With an MA in Automotive Journalism, when he's not testing buckets he can be found looking at old Porsches.