What Output Alternator Is Required For Running A DC-DC Charger?

If you are thinking of installing a DC-DC charger in your vehicle, there are several factors that you need to consider.

These factors include fitting a charger that is suitable for charging your battery size & type, cable sizes, fuse sizes, voltage, ventilation, and also making sure that your alternator is not going to be over-worked by the level of the charger’s output.

As a general rule of thumb, it is advisable to make sure that your alternator output (in Amps) is rated at double the maximum that the charger can put out. For example, if you want to fit a Victron Orion XS 50A DC-DC charger in your vehicle, it would be advisable to have at least a 100A alternator fitted in your vehicle. If you try to draw too much current from the alternator, it could cause it to be overloaded and compromise the alternator's lifespan or, in the worst case, it could burn it out.

Alternators have an output which is measured in Amps (A). Smaller vans are typically fitted with alternators rated between 90-120A, whereas larger vans will typically have alternators rated between 120-180A.  If you're unsure of the output of your vehicle's alternator, it's worth checking with the manufacturer before selecting your DC-DC charger.