Even if it is an inefficient thermoelectric cooler/ fridge/beerbox, they only draw 4 to 5 amps continuously, no second alternator is needed, just for that additional load, but it could help if the coolers run for several hours with the engine off and depletes the battery(s) to low levels where they can suck a lot of amperage.
Does this truck come with a large Inverter and dual batteries?
I've be interested in how the voltage regulator(s?) controls them in parallel. Do they share the load equally?.... or is the second only sent field current when one alternator can't maintain the voltage desired by the voltage regulator due to a large DC load.
While tangentially related. Here is a power curve for different alternators in the same casing from 320 amps to 185 amp rating. The 185 amp rated one starts producing amperage at a much lower rpm, and makes more of it until about 2000 alternator rpm.
I've read on this forum more than once how people assume a higher rated alternator always makes more amperage.
Depends on the pulley ratios, and engine idle speed rpm, but this chart shows otherwise.
All the alternators in this chart below, are the same physical size.
View attachment 33423
View attachment 33424
That's a large frame leece neville 320 amp J-180 saddle mount on the left with , Nippon Denso clone 50/120 amp on the right, which maxes out at 109 amps and has very poor hot idle speed output. of about 32 amps, both numbers shy of its 50 and 120 amp rating.
The one on the right will be my second alternator, but the one on the left could, if driven by a 10 groove serpentine pulley, outperform both.
I'm stuck with Dual V belts and the large frame Leece Beast above, would be extremely difficult to mount to my engine.