CTEK SMARTPASS 120S Power Management System

Price:  £270.37   (£225.31 Exc. VAT)

Product code:  P02053
Brand:  CTEK



1 in stock

Note: Cables not included. Please download installation instructions to determine correct cable size and fuses for your application.

The CTEK SMARTPASS 120S is a fully automatic 120A power management system that prioritises, controls and maximises energy from your alternator to power your auxiliary / leisure battery and has been designed specifically to work alongside the CTEK D250SE DC-DC charger.  A combination of the SMARTPASS 120S + D250SE provides the ultimate power management solution and is recommended for use with batteries (or banks of batteries) greater than 100Ah capacity where there are parallel loads, i.e. where the auxiliary battery is supplying power to consumers at the same time as receiving a charge from the alternator.  In this situation the SMARTPASS 120S will send power directly from the alternator to the consumers, removing all loads from the auxiliary battery whilst it is being charged.

The SMARTPASS 120S safely separates your starter and service batteries automatically so that you cannot accidentally drain one when using the other and distributes power between the starter battery, the service battery and on board equipment without the need for traditional diodes or VSRs.  This makes sure that critical functions like starters, radios, emergency lights and communication systems always have the power they need, and take priority over non-critical functions.

The SMARTPASS 120S features a Start Assistance function that uses your auxiliary battery to start your engine when your starter battery is flat, so you’re back on the road quickly, and if you’re using equipment like winches that need more than 120A, the Dynamic Overcurrent Protection function can provide an output of up to 350A for short bursts up to 10 seconds. It will also trickle charge your starter battery once the auxiliary battery is full and has a built-in battery guard function to prevent over-discharge of your auxiliary battery.

This unit will work with any 12V battery (flooded, sealed, AGM, Gel & lithium etc.) and can be used independently, but works best when combined with the D250SE (link bars to connect the two are provided in the box).


  • Automatic battery separator works without the need for diodes or VSR relays
  • Battery Guard makes sure that critical functions always have power and protects your service battery from total discharge
  • Start Assistance uses power from your service battery to help get your engine started if your starter battery is flat
  • Dynamic Over Current Protection to handle outputs of up to 350A for up to 10 seconds
  • Battery temperature protection switches off charging if your service battery temperature is too high
  • Current Source priority supplies power to critical equipment directly from the alternator when the engine is running
  • Starter battery maintenance charging when your service battery is fully charged
  • Input voltage: 11.5 - 23V DC
  • Input current: 120A continuous (350A intermittent for 10 secs)
  • Output voltage: 23V DC max.
  • Output current: 120A continuous (350A intermittent for 10 secs)
  • Standby current draw: less than 7Ah / month
  • Operating temperature: -20°C to +50°C
  • Lead-acid battery types: Wet, sealed, EFB, Ca/Ca, AGM, GEL, Lithium
  • Battery capacity: 28-800Ah
  • Overall dimensions: 192 (L) x 110 (W) x 65(H) mm
  • Ingress protection rating: IP65 (splash and dust-proof)
  • Weight: 0.7kg

Part Number:  40-289

Bar Code:  7340103402893

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CTEK is a global leader in battery management technology with a huge following in the campervan, motorhome and overland markets. This innovative Swedish company continues to improve and shape the battery management industry with its research and development, which is at the heart of all its products.

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