The AlternatorGenerator, First Attempt. 48V Battery Charging

Will this even work? 48V alternators are expensive. Can we make one from a standard 12V car alternator? I don't know, which is why I decided to try. This video a a complete walk-though, start to finish.

I bought a 12V car alternator off of craigslist for $100. I wasn't looking for any specific model, but I wanted a serpentine pulley on the alternator, and it had to look decent. Next was a Predator gas engine from Harbor Freight. In this case, I purchased the 224cc MAX engine, which is 6.6hp. The 212cc 6.5hp engine would have also worked well for this build.

The goal is to make a dedicated generator that can recharge my 48V battery bank. I'm using the EG4 LiFePO4 batteries, which is a little more than 30kWh. Sometimes, during the winter, the solar production doesn't keep up with my loads. That's when I need to supplement my solar with some generator run-time in order to recharge my battery bank. Yes, 48V generators exist on the market, but they are thousands of dollars. I built this generator for about $400.

Intro: 00:00
Theory of Operation: 00:43
Parts Used: 04:44
Alternator Wiring: 07:04
Building the Base: 16:43
Drive Pulley Installation: 21:05
Wiring the Busbars, Rectifiers, Buck Converter, and Capacitor: 27:45
Test Run: 38:29
Conclusion: 44:20

Amazon affiliate Links:

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Capacitor, 450V, 1000uF: https://amzn.to/3lTHopw

DC to DC Buck Converter, 12V 5A: https://amzn.to/3nug0yK

Charge Controller used in this video (Victron 250/100): https://amzn.to/40k4kNz

Less Expensive Charge Controller: https://amzn.to/3K4fZJE

Engine Hour Meter and Tachometer: https://amzn.to/3KhxMhE

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Tesa Tape, for looming wires together: https://amzn.to/3TXUrTx

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“As an Amazon Associate I earn from qualifying purchases.”

Harbor Freight Links, Not Affiliated:

6.6 Hp, 224cc, MAX: https://www.harborfreight.com/generat...

Band Saw: https://www.harborfreight.com/power-t...

Tap and Die Set, SAE, Titanium: https://www.harborfreight.com/titaniu...

Note: I have no affiliate with Harbor Freight.

Previous Video making a battery charging generator from a free treadmill motor:    • DIY DC Generator: charge batteries off grid  

Signature Solar Affiliate Links:

Battery Bank, EG4-LifePower4, Lithium, 30.72kWh: https://signaturesolar.com/eg4-lifepo...

Inverter kit, Schneider XW PRO 6848: https://signaturesolar.com/bndl-ac-co...

Chargeverter: https://signaturesolar.com/eg4-charge...

Disclaimer:
My videos are in no way intended to be instructional "how-to" lessons. I am simply documenting my project for informational purposes. Property damage, personal injury, or death may result, even when following manufacturer's instructions. I cannot be held liable for such damage or injury. It is YOUR OBLIGATION to ensure that you are complying with any local and federal laws as well as code and permit requirements.

David Poz, LLC