I hope that isn’t true. Guess I’ll find out first hand. Just installed DC Power 240. So far it’s been badass
It's not true, that's not the way electrical works. The only way ANY alternator can hurt your electrical is if the voltage regulator goes bad and it keeps charging at a higher voltage. But don't worry about your electrical, because you would be more likely to explode your battery. (This is if it charges at something north of 18v, and keeps going). You would see it on your gauges, and if your alternator ever did that, you would unplug it / disconnect it, and keep driving for a while until your battery discharged.
Your alternator charges your battery, and the loads on the circuit draw what they need. The electrical items that use, only draw what they need.
There's a lot of misinformation in this thread: Like running 2500 watts on stock electrical. 2500w / 14.4 = 173 amps then your amps efficiency is about 85% and DD is not going to be better than that if that. 173 / .85 = 204 amps. YOU ARE NOT going to run an additional 204 amp draw on ANY stock electrical system.
The OP was also planning on running on stock electrical with 2000 watts (which is right about 163 amps). I wouldn't expect ANY stock electrical system to be ready to handle 100 amps, even if it has an upgraded factory alt for some reason.
It's incredibly simple to figure out what size alt to plan for: total wattage / voltage (14.4 running) = amperage. Amperage / amp efficiency = actual draw, (+what yoru vehicle uses). 2,000 watts being the minimum is an arbitrary number and WAY TOO HIGH anyways. Some people have multiple options for factory alt sizes and could bump it up for small amps. Giving any number out that would apply to all is disingenuous. Some people could need a larger alt for just 30 amps, (or about a 400w amp). There's a few things to figure out first.