Very simply, the voltage range from a smart alternator can be very wide compared to a standard one. For example, around 12V and sometimes exceeding 15V, clearly neither of these are suitable for charging a leisure battery.
What the DC-DC unit does it convert these voltages to a more stable and constant one to provide an efficient and reliable charge to your leisure battery.
In addition the battery charging is provided in three stages - Bulk, Absorption, & Float (Depending on battery technology).
When using Lithium, the unit also has a reactivation feature for batteries in a low state of charge.
Will it work in my van?
Not only will this work with smart alternators, it'll also work with standard ones too. It'll provide a more stable and reliable charge to your leisure battery (extending life & available capacity) over a traditional voltage sensitive relay. It'll also allow you to run lithium battery technology.
Such vans as the below will normally have a smart alternator fitted, but if you're not sure, or your van isn't listed, please just drop us a message and we should be able to confirm its technology.
Late Volkswagen Transporter T5.1
Volkswagen Transporter T6
Volkswagen Transporter T6.1
Ford Transit Custom
Late Ford Transit
Late Mercedes Sprinter
Late Volkswagen Crafter
What battery technology does it support?
You can use this DC-DC unit to charge the following battery types, you just need to select the correct settings on the dip switches.
Sealed lead acid
Flooded lead acid
What's the optional battery temperature sensor?
The DC-DC unit can come with an optional temperature sensor, it simply plugs into the RJ11 port and the probe placed in contact with your leisure battery.
With this sensor fitted, it will monitor the temperature of your leisure battery and adjust the charging rate in line with the battery temperature. For example if you battery was very cold it would increase the output.
The unit will work without the sensor, its just an option should you want it as it may increase battery life and maximise capacity.
Depending on stock, this will be either a single probe (pictured) or a probe mounted inside a ring terminal.