smart alternators

[jx2mad]

Here is one for the electrical gurus. Having just purchased a new D-Max I find that the alternator is one of the smart type. So I ask what device do I need to run to charge a second battery? It seems that these new alternators drop their output voltage after a time so if the volyage drops then how to charge a second battery let alone the main battery. It is recommended on the D-Max site to regularly charge the main battery from an external charger. Great technology.

[drivesafe]

Hi Jim and there are two primary types of “Smart Alternators”.

The first is a time based operation, where the alternator runs at a higher ( boost ) voltage straight after the motor is first started and then after a period of time, the alternator voltage drops to a lower normal operating voltage.

This is the type used in most Asian vehicles, like Toyota’s and, from some limited research I’ve done, is similar in D-Max.

But if you can, try testing your cranking battery voltages at different times during a trip.

If you can post up your voltages, I can give you an idea of what you may need.

[jx2mad]

I can do that but it may take some time. I am now recovering from driving all over the place for Christmas, so hopefully not driving much for a while

[drivesafe]

Hi Jim as it’s for your benefit, do it at your leisure.

Just post up your measurement when you get them and I can compare with the info I have and see if we can set you up for the best results.