The Sterling 'Pro Batt Ultra' 24V/24V 35A Battery-To-Battery charger offers fast, multi-stage charging of auxiliary batteries in automotive, marine and recreational vehicle applications. Simple to install and configure, it provides a much deeper and faster re-charge than connecting directly to the alternator and is essential if you intend to re-charge a second battery in a modern vehicle where the introduction of 'smart' alternators has rendered traditional voltage sensitive relays (VSRs) redundant (please see download section below for more info).
Smart alternators are ECU controlled and their voltage output varies continuously throughout a journey. Often the voltage is too low to provide any charge to the batteries via a VSR and at other times the voltage is very high (with regenerative braking systems) which can damage sealed, AGM & Gel batteries.
Sterling Battery-To-Battery chargers take the variable voltage output from the alternator and boost or reduce it to maintain a stable voltage output according to a multi-stage charging profile, providing a safe, controlled and fast charge for your auxiliary battery. Another benefit is that current flow is limited by the charger's current rating, eliminating potentially damaging high in-rush currents to deeply discharged batteries and allowing the use of smaller connecting cable compared with VSR split charge systems (which need to handle the max. alternator output). Importantly, once the engine is turned off the charger automatically isolates the starter and leisure batteries from each other to prevent accidental discharge.
Compatible with the following manufacturer's technologies plus many other Euro 5/6 + vehicles that use smart alternators & regenerative braking.
|® Trademark of Mercedes Benz||® Trademark of Volkswagen||® Trademark of Vauxhall||® Trademark of Ford|
- Suitable for all battery types (wet lead acid open and sealed, AGM, gel, lithium and calcium).
- No connection to alternator required (no warranty issues)
- No adverse effect on ECU
- Around 5x faster charging than traditional split charge systems
- Multi-stage profile for a deep charge and long battery life
- Solves Euro 5/6+ smart alternator and regenerative braking issues that make VSRs redundant
- Input voltage boost/reduction for stable and correct charging profile
- Automatic battery isolation/separation with engine off
- 9 preset battery chemistry options to suit all battery types, plus user-customisable profile
- Comprehensive front panel display
- Quick and simple to install - cables not included
- Dynamic thermal charging via IP68 waterproof temperature sensor (included)
- Night time setting for silent running (no fan) at 50% power
- Fire-proof plastic enclosure
- Designed in the UK
We recommend this 35A charger for use in the majority of campervan and motorhome applications that have a leisure battery (or bank of batteries) up to around 220Ah in capacity. For larger battery banks and/or faster charge rates, consider the 60A model.