Couple of questions about DC-Dc charging
I've been thinking about adding a DC-DC charger now that I've added 400 amp hours of AGM batteries. There are lots of useful posts but I haven't run into a couple of things I'm curious about. One ...
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That is probably too much current for a 135A alternator to sustain, but does it actually provide this much current without a huge load? What is the current when just charging the batteries?
Most modern alternators are ECU controlled (although I don't specifically know about the F53/Triton) and are self regulating - the ECU monitors the alternator temperature and will decrease the output voltage (and thus the load) if the alternator gets too hot. However, this won't work with a DC-DC converter as it will draw more current if the input voltage decreases.
A general rule of thumb is that you can safely run an alternator continuously at 50- 60% of its peak rating, but this is just a guideline. Run the batteries down to 50% SOC or so and then fire up the engine and see what your actual current draw is, and if the alternator throttles back. If you in fact do have an an issue, instead of a DC-DC converter that will limit your charging current, a higher output alternator may be a better investment.
Most modern alternators are ECU controlled (although I don't specifically know about the F53/Triton) and are self regulating - the ECU monitors the alternator temperature and will decrease the output voltage (and thus the load) if the alternator gets too hot. However, this won't work with a DC-DC converter as it will draw more current if the input voltage decreases.
A general rule of thumb is that you can safely run an alternator continuously at 50- 60% of its peak rating, but this is just a guideline. Run the batteries down to 50% SOC or so and then fire up the engine and see what your actual current draw is, and if the alternator throttles back. If you in fact do have an an issue, instead of a DC-DC converter that will limit your charging current, a higher output alternator may be a better investment.
