The introduction of the smart battery charger has been a very clever way of ensuring that car batteries not only remain topped with electricity but that the internals remain healthy so the battery lasts as long as possible.
On the face of it, car batteries look to have remained largely the same for decades. A heavy box with some electrons in it. But modern car batteries are far more advanced than those fitted to your dad’s Vauxhall Cavalier to keep up with the electrical requirements of modern cars.
Modern cars demand a lot more power than the cars of yesteryear, thanks to safety systems, onboard computers, stop-start technology and all that sort of thing. Thus, batteries need to be able to hold more charge and charge faster, and in doing so, will not tolerate abuse and poor treatment by owners.
The best smart battery chargers at a glance:
Editor's choice: CTEK CS FREE Portable Battery Charger - Buy now from Amazon UK
Best all-rounder: CTEK MXS 5.0 Smart Battery Charger - Buy now from Amazon UK
Best for budget: Ring Automotive RSC808 Battery Charger - Buy now from Amazon UK
Smart chargers have a multi-stage cycle when charging car batteries. This begins with something called desulphation – restoring battery capacity by removing sulphate from the battery’s lead plates. The smart charger will then test the battery to see if it is able to accept charge. It’ll then go through a series of subsequent steps, including reconditioning the battery (if you have this mode selected), and once the battery is fully charged, it will automatically switch to a pulsing trickle charge to keep the battery level topped up but without over-charging it.
The best smart battery chargers
Editor's choice
Via CTEKCapable of recharging a dead battery in as little as 15 minutes, this portable battery charger from CTEK is one of the best in the business. Not only can it bring life into a dead battery, but it doubles as a trickle charger too - and it can be solar powered as well.
It recharges via USB-C, can hold up its charge for up to a year, and has some useful power bank functions.
Pros
- Doubles as trickle charger
- Multiple recharging methods
Cons
- Storage case isn't included
Best with cold weather mode
Tested
The RSC806 is a compact and simple-to-use charger and maintainer that works on most 6V/12V batteries. That includes start/stop, but not lithium. The RSC806 also has a 6A output for quicker fill-ups. It comes with an O-ring lead for permanent mounting and crocodile clips for ad hoc charges. Both connect to the unit's long lead with a quick-release bullet connector.
Capable of charging and maintaining cars and motorbikes, this is a very flexible product that also boasts IP65 weatherproofing and a winter maintenance mode if your vehicle is laid up during the colder months. For ease of use, the charger automatically shifts to 'long-term maintenance mode' once your battery is full and promises to keep it conditioned and topped up, ready to go in spring.
Reverse polarity and short-circuit protection are reassuring additions, as is the one-button operation - just select the mode you want and walk away. It even has a built-in hook for wall mounting. Our only real gripe is the size of the holes in the O-ring lead. They're a tad large for a motorbike battery, and the fact you have to be at just the right angle to read the screen. But as a fit-and-forget item (until winter's over at least) it's very impressive.
Pros
- IP65 rated
- Cold weather mode for winter
Cons
- O-ring holes are a bit large for motorcycle batteries
| Dimensions: | (L) 183mm x (W) 101mm x (H) 63mm |
| Weight: | 0.88kg |
| Current: | 3A or 6A |
| Voltage: | 6V, 12V |
| IP rating: | IP65 |
| Operating temperature: | Not given |
Best all-rounder
The CTEK MXS 5.0 is simply everything you want from a battery charger. It's well-made, affordable, fully automatic, and works on all battery types, including AGM. You can choose between a regular charge mode that skips reconditioning or one that includes it.
Pros
- IP65 rated
- Deep reconditioning cycle
- Automotive temperature compensation for optimising performance
Cons
- Pricey compared to Ring RSC806
| Dimensions: | (L) 168mm x (W) 65mm x (H) 38mm |
| Weight: | 0.6kg |
| Current: | 5A |
| Voltage: | 12V |
| IP rating: | IP65 |
| Operating temperature: | -20° to 50° C |
Best easy to use smart battery charger
The CT5 Time To Go unit is quite similar to the MXS 5.0 from CTEK. The difference lies in the CT5's unique feature that tells you how much time is left in the charge cycle. Like the MXS 5.0, the CT5 has normal and reconditioning charging modes and is good for all battery types.
Pros
- Countdown displayed
- Similar specs to MXS 5.0
Cons
- Is that countdown worth the extra cost to you?
| Dimensions: | (L) 168mm x (W) 65mm x (H) 38mm |
| Weight: | 0.6kg |
| Current: | 5A |
| Voltage: | 12V |
| IP rating: | IP65 |
| Operating temperature: | -20° to 50° C |
Best for budget
Via RingSuitable for both 12V and 24V vehicles, the RSC808 is one of the best battery and trickle chargers you can get on the lower end of the spectrum.
It's easy to use as well. You can set it to trickle charge by selecting maintenance mode to keep a static vehicle in check. It's also a lightweight and compact charger to have on hand, so you can keep it in your vehicle, should the time come to need it.
Pros
- IP65 Rated
- Great for cold weather
Cons
- Won't be as good quality as the CTEKs
Smart battery charger tips
It is worth remembering that while the units above all do a great job of charging and reconditioning car batteries, it can take time. Charging times vary enormously depending on the battery size and the level of discharge. Therefore, asking how long a charge cycle will take is like asking how long a piece of string is.
Read the instructions about how to connect the charger to the battery correctly. Always connect with the car off.
Chargers such as these are meant for use at home. If you are out and about and end up in the fortuitous scenario of a flat car battery, don’t forget portable power packs and jump starters exist to help you. They are small and very handy to keep in the glovebox. Many of them also double as a regular power bank for phones and other devices.
Aaron Hussain is a commercial content writer at Bauer Media writing for Parkers and CAR. He is obsessed with classic cars and anything with a fascinating story to tell.