iamdub
Full Access Member
Of course, the first one I looked into was the various offerings from MechMan. Their basic, entry level ("Elite" series) alternator is exactly what I outlined- 250A (with 180 at idle), stock pulley (so no excessive alternator speed when engine is at 6,000+ RPM), plug-and-play and retains RVC. I can't speak for the '07-'20 using the same. MechMan has different part numbers for the '05-'13 and '14-'21 for the same spec of alternator. I also looked at JS Alternator's "Hairpin" units which look to be comparable in specs, but $90 cheaper. They use a smaller (overdrive) pulley on their alternators. So, getting a smaller belt to replace the one I haven't had for very long would eat up half of those savings. That and overdriving the alt pretty much turns me away. MechMan rates their output at 1,800 RPM engine speed and lists the output at idle.
To a point, "too much" is better than not enough. Like a battery, the alternator isn't gonna "push" more amperage into the devices and systems it is powering. It'll just have the capacity to maintain 12+ volts when loaded down by those devices and systems. The threshold is how they get the extra power. You can only do so much with upgrading the alternator's components. Beyond that, they gotta speed up the alternator and that incurs extra loads on the engine and the alternator's bearings, etc. Not to mention requiring a different size of belt. Some places jump straight to a smaller pulley before other, better modifications. Ideally, you wanna get all the amperage you need from a stock-sized alt and pulley so you can use a stock belt.
If I'm not mistaken, the extra battery is just paralleled off the other one. So, you could look at it as if it's one big battery. The RVC activates by monitoring the amperage on the ground cable and system voltage and adjusting the alternator's output accordingly. With twice the battery capacity, the amperage and voltage would be more stable under higher loads. So, the RVC would just not have the alternator charging as often compared to a like-equipped Tahoe with a single battery.
*EDIT* I see @Sparksalot filled you in as I was typing up my novel.
