Dc-dc charging

Putting a bluetti charger1. (Fast charger) in rig for my new topper. Will only be used while driving to charge my bluetti AC200L power pac while heading to new locations. Will I need a heavy duty alternator for this set up? Also, could someone verify if my 2014 Tacoma 2.7 has a smart alternator or not. I found nothing attached to negative cable on battery at terminal to say it was a smart alternator. Is this all I need to look for, I do not yet have a meter to watch draw.

 

What's the wattage output of your DC-DC charger?

 

560 watts

 

Youre on the limit. 2.7 liters came with a 100 amp alternator. The charger draws 50. The normal capacity of your battery is ~80 amp hours, and lead acid batteries charge at around 0.2C, or ~16 amps in your case. So that brings you up to 66 amps if the batteries are fully dead. It's normally recommended to not exceed 70% rated capacity on the alternator, so you'll be close to the recommended limit, and likely over when also running the truck and other accessories, especially at night.

That being said, frequency of you having 2 batteries <80% and needing to have headlights on and stereo cranked, and etc. etc. is likely not a common occurrence. I would run the 100 amp until it dies, then replace it with a bigger one for piece of mind.

 

Much appreciated. Everything you said made sense with all I have read, just could not put it together like that myself.

 

The alternator is internally regulated, it's temperature compensated but that's about the extent of it's "smarts".

Typical charging voltage on these is around 13.7-14 cold and 13.2-13.4 hot.

Voltage is sensed on the S-Terminal (Pin 1 (White)).
Some people "trick" it into charging at a higher voltage so they can use an AGM battery by replacing the ALT-S fuse with a diode, that drops the voltage at the S-Terminal by about 0.5v so it charges around 0.5v higher than it normally would.