Yes it is the relay resetting the open circuit mode, just check the terminals are firmly connected to the battery and the noise will stop soon enough
CTEK CS FREE is the world’s first truly portable battery charger and maintainer with Adaptive Boost technology.
You can charge and maintain any 12V lead-acid or lithium vehicle battery anywhere without being connected to a power outlet. And if your battery’s flat, CS FREE’s revolutionary Adaptive Boost technology will get you going within 15 minutes.
Portable charging and maintaining you can take anywhere without being tied to a power outlet
• Internal battery lasts up to a year when fully charged
• Adaptive Boost, to safely get you going from a flat battery within 15 minutes
• Can be charged up and powered by solar or 12V battery for longer-term maintenance charging
• No modes to select – just turn it on, connect and the CS FREE will do the rest
• Countdown function shows you how long there is left before your battery is fully charged
• USB-C and USB-A outputs for charging tech like laptops, smartphones & tablets
• New ergonomic design with a tough and durable case
• 2 year ‘peace of mind’ warranty
Additional Accessories available include:
| TECHNICAL DATA | |
| INPUT USB-C | 5 VDC – 25 VDC, 3 ADC/60 W max |
| OUTPUT | 12 V, 20 A/240 W max |
| START VOLTAGE | 3.0 V |
| AMBIENT OPERATING TEMPERATURE | -20 ˚C to +50 ˚C (- 4 °F to +122 °F) |
| AMBIENT STORAGE TEMPERATURE | -20 ˚C to +45 ˚C (- 4 °F to +113 °F) |
| BATTERY CHEMISTRY | Lead acid, Lithium |
| BATTERY TYPES 12 V | WET, MF, Ca/Ca, AGM, EFB, GEL, LiFePO4 |
| BATTERY CAPACITY | 10-130 Ah |
| DEGREE OF PROTECTION | IP54 |
| WARRANTY | 2 years |
| NET WEIGHT (UNIT WITH CABLES) | 1.4 kg |
| DIMENSIONS | (L x W x H) 248 x 98 x 78 mm |
| 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 |
| MAINS ADAPTER | |
| INPUT | 100 VAC – 240 VAC, 50 Hz – 60 Hz, 60 W max |
| OUTPUT USB-C | 5 VDC – 20 VDC, 3 ADC, 60 W max |
| CABLE LENGTH | 1 m |
| CABLE TYPE | USB-C |
| INTERNAL BATTERY | |
| CAPACITY | 66 Wh |
| CELL CHEMISTRY | Polymer Lithium-Ion |
| CELL TYPE | Pouch Cell |
| DISCHARGE TEMPERATURE | -20 ˚C to +50 ˚C (- 4 °F to +122 °F) |
| CHARGE TEMPERATURE | 0˚C to +45˚C (32˚F to 113˚F) |
| SHELF LIFE | 1 year |
| LIFE SPAN | 300 cycles, 80% |