CTEK Battery Charger - 8A CS One (Gen 2) NA w/Wi-Fi & Bluetooth - 12V - 40-704

The CTEK CS ONE (Gen 2) 8A Battery Charger (MPN 40-704) is a 12V smart charger built for anyone who wants an intelligent, connected way to charge and maintain a vehicle battery without guesswork. With an 8-amp charging current, polarity-free clamps, and full Wi-Fi and Bluetooth integration through the CTEK App, this charger is designed for cars and motorcycles alike, giving DIYers and enthusiasts a dependable way to keep a 12V battery healthy year-round.

Key Features & Benefits

• 8A Charging Current — delivers efficient, adaptive charging for virtually any 12V battery, helping you get back on the road faster than a basic trickle charger.
• Polarity-Free Clamps — the clamps work either way around, so there's no risk of connecting them backwards, making hookup simple and safe every time.
• Wi-Fi & Bluetooth Connectivity — full integration with the all-new CTEK App transforms how you interact with your charger, letting you monitor charging status and control the unit remotely.
• Intelligent, Adaptive Charging — the CS ONE (Gen 2) is engineered to charge and maintain virtually any 12V battery intelligently rather than applying a flat, one-size-fits-all charge.
• Battery Charger and Trickle Charger in One — suitable both for actively charging a depleted battery and for longer-term maintenance charging when a vehicle sits.
• Versatile Use — works across cars and motorcycles, making it a practical single charger for garages with multiple 12V vehicles.

Specifications

• Model: CS ONE (Gen 2) NA
• Charging Current: 8A
• Voltage: 12V
• Connectivity: Wi-Fi & Bluetooth with CTEK App support
• Manufacturer Part Number: 40-704
• UPC: 7340103407041

Fitment

This is a universal 12V battery charger, not a vehicle-specific part — it's built to charge and maintain virtually any 12V battery, and CTEK positions the CS ONE (Gen 2) for use on cars and motorcycles. If you're maintaining a 24V system or need dedicated lithium-specific charging, check CTEK's other charger lines, as the CS ONE (Gen 2) is a 12V unit.

Why Buy from ThreePiece.us

ThreePiece.us backs every order with free shipping and financing through Affirm, so you can add the CTEK CS ONE (Gen 2) to your garage without paying the full amount upfront. Our team is also on hand to help you confirm compatibility with your specific battery setup before you order, so you can buy with confidence.

Frequently Asked Questions

Does the CTEK CS ONE (Gen 2) work on both cars and motorcycles?
Yes — it's designed as a versatile 12V charger for cars and motorcycles.

Do I have to worry about connecting the clamps the wrong way?
No — the CS ONE (Gen 2) uses polarity-free clamps that work either way around, so hookup is always safe.

Can I monitor charging remotely?
Yes — the charger includes Wi-Fi and Bluetooth connectivity paired with the CTEK App, giving you remote access to charging status.

Is this charger only for charging, or can it maintain a battery long-term too?
It functions as both a battery charger and a trickle/maintenance charger, so it can be used for an active charge or left connected for ongoing maintenance.