CTEK’s CS FREE is the world’s first multi-functional portable battery charger and smart maintainer with Adaptive Boost technology. You can charge and maintain any 12V lead acid or lithium battery anywhere using mains, solar or leisure battery power. And if your battery’s flat, CS FREE’s revolutionary Adaptive Boost technology will work out the safest and quickest way to power up your battery to get you going within 15 minutes.

Part no. 40-462


Multi-functional portable charger and smart maintainer with Adaptive Boost technology

CS FREE gives you the freedom to charge and maintain any 12V lead acid or lithium battery wherever you are – even if you’re nowhere near a power outlet. Use it as a portable charger to top up your battery with mains power, or hook it up to a solar panel kit or 12V battery for complete charging freedom anywhere you go. CS FREE also features our revolutionary Adaptive Boost technology so if your vehicle won’t start, just connect it up and CS FREE will automatically analyse the state of your battery. It’ll then work out the safest and quickest way to give it the power it needs to start your vehicle within 15 minutes. Unlike most ‘boosters’, CS FREE is sensitive and safe, so it avoids damaging your battery or your vehicle’s electronics by only giving it the charge it needs to get you going. CS FREE is also a smart maintainer and hi-tech powerbank to keep your battery and tech powered up so they’re always ready to go.


  • Works with all types of 12V lead acid and lithium batteries
  • Suitable for use on motorbikes, cars, leisure vehicles and vans
  • Countdown function shows you how long there is left before your battery is fully charged
  • Can be left safely connected for smart maintenance charging
  • Can be charged and used with 12V accessory socket, service battery or solar panel
  • USB-C and USB-A outputs for charging tech like laptops, smartphones and tablets
  • Easy to use, easy to operate, easy to understand
  • No modes to select – just connect and the CS FREE will do the rest
  • Complete range of accessories available for mains free charging and handy storage
  • New ergonomic design with a tough and durable case.
  • Easy to carry around or wall mount using the optional CS Wall Mount
  • 2 year ‘peace of mind’ warranty

Technical data

Battery capacity
10-130 Ah
Battery capacity CEC-400
10-130 Ah
Charging category
DC charging
Battery voltage
12 V
Battery chemistry
Ambient storage temperature
-20 °C to +45 °C (-4 °F to +113 °F)
Ambient operating temperature
-20 ˚C to +50 ˚C (- 4 °F to +122 °F)
Natural convection
USB-C, 5 VDC – 25 VDC, 3 ADC/60 W max
12 V, 20 A/240 W max
Start voltage
3.0 V
50-60 Hz
Battery types
Enclosure material
Rated voltage (Input)
100 VAC – 240 VAC
Degree of protection
Dimensions (L x W x H)
9.8 x 3.9 x 3.1 in
Dimensions (L x W x H)
248 x 98 x 78 mm
Dimensions (L x W x H)
9.8 x 3.9 x 3.1 pulgadas
Net weight (unit with cables)
1.4 kg
User interface
LED symbols
Net weight (unit with cables)
3 lbs
Net weight (unit with cables)
3 libras
Detachable charging cable length (ouput)
2 m
Internal battery capacity
66 Wh
Internal battery cell chemistry
Polymer Lithium-Ion
Internal battery cell type
Pouch Cell
Internal battery charge temperature
0˚C to +45˚C (32˚F to 113˚F)
Internal battery discharge temperature
-20 ˚C to +50 ˚C (- 4 °F to +122 °F)
Internal battery life span
300 cycles, 80%
Internal battery shelf life
1 year
Internal battery weight
0.5 kg
Mains adapter cable length
1 m
Mains adapter cable type
Mains adapter input
100 VAC – 240 VAC, 50 Hz – 60 Hz, 60 W max
Mains adapter output
USB-C, 5 VDC – 20 VDC, 3 ADC, 60 W max
USB-C input
USB-A Output
5 VDC, 2.4 ADC/12 W max
USB-C Output
5 VDC, 9 VDC, 12 VDC, 15 VDC, 20 VDC, 3 ADC/60 W max
2 years
Warranty, info
Limited Warranty
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.

CTEK CS FREE awarded Auto Express product of the year.

The CTEK CS FREE the world’s first multi-functional portable charger, was commended for its revolutionary Adaptive Boost technology, that gets your car going from a flat battery within 15 minutes, its ability to top-up a little-used car stored away from mains power, and clever introduction of accessories to enable off-grid charging via solar power or a second 12V service battery. 

Read the news story

The CS FREE is a portable Adaptive Booster that will get you going from a flat battery within 15 minutes.

Just charge up the CS FREE’s internal battery and you’ve got a 12V power bank that will stay fully charged until you need it – for up to a year. And with USB-C connectivity, you can fully recharge your CS FREE in just one hour!

If you have a car, a motorcycle, a boat or any other 12V vehicle and want to charge and maintain for longer periods of time…well no worries! We some handy accessories to enable charging via solar panel or a 12V service battery.

Portable charging and Adaptive Boosting you can take anywhere. The CS FREE: it’s a fully portable 12V Power bank for your vehicle.

•  No need to be tied to a power outlet.
•  Internal battery charges up within 1 hour.
•  Stays fully charged for up to a year.
•  Adaptive Boost gets your flat battery safely charged up within 15 minutes without damaging your vehicle’s electronics.
•  Charges and maintains all types of lead acid and lithium batteries and keeps them in peak condition.
•  Simple to use – no modes, just a clear, easy to read display.
•  Charges up your portable tech – smart phones, tablets and laptops etc.
•  Recharge or power from service battery and solar.

Flat battery? No problem!

Maybe you don’t use your vehicle every day, or you have a car, motorcycle or another leisure vehicle that only gets taken out every now and then – or you keep it in storage over the close season.  One day you decide to take it out but – and probably not for the first time – you find your battery’s flat. So what happens next – how do you revive a dead battery?

If your vehicle’s near a power outlet and you already own a battery charger – or you can borrow a friend’s – you should be able to connect it all up and the vehicle might be good to go in a few hours. 
But what if you’re nowhere near a power outlet and you need to get going a lot quicker?  It doesn’t matter how powerful your regular battery charger is – if you can’t plug it in anywhere, it’s no use to you. 

You could be stuck at the side of the road, in a public car park or out in the wild – but if your battery’s flat and you can’t get power, you’re not going anywhere.

What is Adaptive Boost?

The CS FREE is an Adaptive Booster that will get you going from a flat battery within 15 minutes. It automatically analyses the state of the battery and works out the safest way of giving it enough power to start the vehicle. Unlike most boosters or jump starters, the CS FREE is sensitive to the state of the battery and only gives it the charge it needs to get you started. So it's a 12V power bank for your car or other vehicle that is completely safe for the battery and your vehicle electronics.

We have some handy accessories to enable charging via a solar panel or 12V service battery.

Attach the USB-C charge clamps to a separate 12V service battery, for battery charging and maintenance, without needing to connect to a power outlet.

The CTEK Solar Panel pairs perfectly with the CS FREE, so you can charge your battery via a solar panel and use it wherever you are. Fold it, transport it, and connect it in seconds, this intelligent and responsive solar panel kit delivers reliable solar power whenever you need it.

Made from tough and durable 600D water-resistant nylon, with a padded interior, the CS FREE storage bag provides practical storage and protection for your CS FREE.

Plug the USBC-C charge cable into your vehicle’s 12V accessory socket and recharge your CS FREE in just 1 hour.

Featuring CTEK’s unique mounting system, the CS Wall Mount provides practical storage for your CS Charger, neat cable management as well as quick and easy access whenever you need it.