Charging any battery just got a whole lot simpler with the CTEK CS ONE. Its revolutionary APTO™ (Adaptive Charging) technology does all the thinking for you – you don’t even have to worry about which clamp goes where! This is the easiest charger you’ll ever use. Add in dedicated app control, to unlock additional features and you’ve got the most advanced charger available today. Super simple. Super smart. Simply CS ONE.

Part no. 40-331


Revolutionary adaptive battery charger and maintainer

APTO™ Technology automatically recognises the type of battery you’re using, and then automatically delivers a customised charging program, telling you how long until the battery is charged and ready to go. No buttons to press or modes to select – just connect the CS ONE to any 12V battery and simply charge. Polarity free clamps mean you don’t even need to worry about which clamp goes where, so you’ll never make a wrong connection again. The clamps are spark free too, so don’t worry if you accidentally touch them together. Unlock additional features using the Bluetooth® enabled CTEK App. Select ‘RECOND’ to restore and recondition your battery. Choose ‘WAKE UP’ for lithium batteries with under voltage protection or to bring deeply discharged lead-acid batteries back to life. Select ‘SUPPLY’ to turn the CS ONE into a useful 12 V supply. You can also monitor the voltage and amps being delivered by the charger.


  • RECOND option to restore and recondition lead-acid batteries.
  • WAKE UP option to revive seemingly dead lithium and lead-acid batteries.
  • 12V SUPPLY to support the battery during service work and retain contact power to the vehicle during battery replacement / removal.
  • ADVANCED SETTINGS to monitor charger voltage & amperage.
  • Can be left safely connected for long periods during maintenance charging.
  • New durable design to make it easy to handle, with unique mounting system on the back for quick connection to CS accessories.
  • 5 year warranty.

Technical data

Battery capacity
3–180 Ah
Battery capacity CEC-400
3–180 Ah
Charging category
AC charging
Back current drain*
Corresponding to less than 1.5 Ah/month
Battery voltage
12 V
Battery chemistry
Lead acid; Lithium-ion
Ambient operating temperature
-30 °C to +50 °C
Natural convection
220–240 VAC, 47–63 Hz, 1.2 A
12 V, 8.0 A
Start voltage
1.5 V lead-acid battery types. 1.5 V LiFePO₄.
50 Hz
Less than 4 %
Battery types
12 V:; WET; MF; Ca/Ca; AGM; EFB; GEL; LiFePO₄
Temperature compensation
Built in charge voltage compensation according to ambient temperature.
ETSI EN 300 328; RED; EN 61000-6-3; EN 61000-6-1; ETSI EN 301 489-1; ETSI EN 301 489-17; EN 60 335-2-29; EN 60335-1; SS-EN ISO 13732-1:2008
Enclosure material
Rated voltage (Input)
230 V
Degree of protection
Mains cable length (input)
1.4 m
App support
CTEK App for Android and IOS
Dimensions (L x W x H)
235 x 88 x 52 mm
Net weight (unit with cables)
0.675 kg
User interface
LED symbols; Smartphone display (free of choice)
Detachable charging cable length (ouput)
2 m
Packaging size (L x W x H)
288 x 178 x 55 mm
5 years
Warranty, info
Limited Warranty
Power plug type
Type G
*) Back current drain is the current that drains the battery if the charger is not connected to the mains. CTEK chargers have a very low back current.
**) The quality of the charging voltage and charging current is very important. A high current ripple heats up the battery which has an aging effect on the positive electrode. High voltage ripple could harm other equipment that is connected to the battery. CTEK battery chargers produce very clean voltage and current with low ripple.
CTEK issues a limited warranty to the original purchaser of the product. Depending on the product, the limited warranty period will vary. The limited warranty is not transferable. The warranty applies to manufacturing faults and material defects. The warranty is void if the product has been handled carelessly or repaired by anyone other than CTEK or its authorized representatives. CTEK makes no warranty other than this limited warranty and is not liable for any other costs other than those mentioned above, i.e. no consequential damages. Moreover, CTEK is not obligated to any other warranty other than this warranty.

Charge up with CS ONE. Plug in to brain power

Get to know the CTEK CS ONE – the revolutionary battery charger and intelligent maintainer with APTOTM (Adaptive Charging) technology. Hands down the most innovative battery charger ever engineered by CTEK, CS ONE comes to you with cutting-edge APTOTM technology that’s so advanced it does all the thinking for you. 

This is the ONE battery charger capable of delivering a whole new dimension of smartness and simplicity. ONE so ground-breaking, it supports polarity-free charging. ONE you simply plug in to the mains, attach to any 12V battery and rely on to deliver consistently optimal performance. We call that pure brain power, wouldn’t you?

Stress-free, safe and secure battery charging and conditioning. Isn’t it all you’ve ever wanted?

The CTEK CS ONE uses Adaptive Charging Technology, or APTOTM technology as we call it, which recognises what type of battery you’re using, how big it is and what type of charge it needs. A dedicated and unique charging programme is then automatically delivered to the battery, to exactly meets its needs. The charger will also tell you how long it is until the battery is charged and ready to go. An in-built temperature sensing will automatically adjust the output voltage in both cold and hot conditions for the fastest and safest charging times.

Engineered for your complete safety and peace of mind, CS ONE features polarity- and spark-free clamps. You will never again have to worry about making a wrong connection, or worry about the clamps touching together whilst connecting. Easy-to-follow countdown LEDs give a visual indication about the time remaining for the battery to be fully charged and even when you can restart a flat battery.

So advanced, it simply works

The CS ONE is so smart that it delivers another dimension of simplicity. You will not have to waste time with buttons or modes, with all the information you need clearly available via a simple smart display. It comes with a dedicated, free-to-download CTEK App that will unlock additional features such as ‘RECOND’ to restore battery health, ‘WAKE UP’ for lithium batteries with under voltage protection (UVP) or to bring deeply discharged lead-acid batteries back to life, and ‘SUPPLY’ to turn CS ONE into a 12V supply. The CTEK App is also developed to give you complete control through your smartphone.

The world’s smartest, fully adaptive charger

CTEK CS ONE takes a whole new, revolutionary approach to battery care. We were the first to market with smart charging and now, thanks to our revolutionary APTOTM technology, we have launched the first fully adaptive charger. And it’s down to this technology that smart just got easy and easy just got smart! The CS ONE goes beyond traditional multi-step charging – it’s the world’s smartest, fully adaptive charger that really does do all the thinking for you. And with the introduction of polarity free clamps it’s so safe and easy to use.

ONE battery charger. Complete flexibility

The CS ONE has been developed to be completely compatible with use on cars, motorcycles, leisure vehicles, vans, and boats. Its hallmark is the utter ease of use, requiring no modes to select – just connect and the CS ONE will do the rest. That’s it! This makes the CS ONE the ultimate battery charger, conditioner and maintainer for every driver in the world. Because, what it gives you is superior freedom and peace of mind. So much so that it can be left attached to the battery indefinitely, with you having absolute certainty that your vehicle is always ready to go when you are. Clearly, this is the ONE charger to have.

The ONE and only with pure brain power

•    Super Smart and Super Simple
No buttons to press or modes to select – simply connect to any 12V lead-acid or lithium (LiFePO4) battery and leave it to do its work.
•    Adaptive Charging Technology (APTOTM)
Automatically works out what type and size of battery you’ve got and what it needs, then delivers a customised charging programme with the most appropriate charge.
•    Polarity Free Clamps
Just put one clamp on each charging point and the CS ONE will automatically work out which is the positive and which is the negative terminal.
•    Bad cell detection
The CS ONE can tell if your battery can’t be charged – and will notify you.
•    Easy to understand display
Countdown indicator shows when you can restart your vehicle and how long to go until fully charged.

Technology called APTO™️. Does all the thinking so you don’t have to

APTO™️, or Adaptive Charging Technology, is the result of years of research, development and testing by CTEK. The brainchild of CTEK creativity, technical expertise and perseverance, the technology is set to revolutionise battery charging. 

APTO™️ in the CS ONE makes for a whole new dimension of smartness and simplicity. It has been developed to communicate with the battery to understand size, chemistry and health. This information is then utilised to automatically deliver a customised charging programme (2-8 Amps) that will optimise battery performance. Furthermore, an in-built temperature sensor will automatically adjust the output voltage in both cold and hot conditions for the fastest and safest charging times.

Suitable accessories