Can we charge a 48V off grid battery bank with a 12V car alternator and small gas engine?
Video Part 1 was building the alternator generator project: https://youtu.be/CL8W5hipaLM
Video Part 2 was fixing problems, answering questions, and running our first fuel economy test. We also checked for over-heating issues: https://youtu.be/cy0t4qq8mS0
This video is part 3, and we find the sweet-spot for fuel economy.
Video, Honda EU6500 Inverter Generator: https://youtu.be/kQTFPMDE_F4
I bought a 12V car alternator off of craigslist for $100. 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.
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Signature Solar Affiliate Links:
Battery Bank, EG4-LifePower4, Lithium, 30.72kWh: https://signaturesolar.com/eg4-lifepower4-lithium-batteries-kit-30-72kwh-6-server-rack-batteries-with-free-pre-assembled-enclosed-rack-with-door-wheels-busbar-covers/?ref=4_rHcgZ9x-TiF-
Inverter kit, Schneider XW PRO 6848: https://signaturesolar.com/bndl-ac-coupling-with-single-inverter?ref=4_rHcgZ9x-TiF-
Chargeverter: https://signaturesolar.com/eg4-chargeverter-gc-48v-100a-battery-charger-5120w-output-240-120v-input-pre-order/?ref=4_rHcgZ9x-TiF-
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Amazon affiliate Links:
Thermal IR Camera, Android (used in video): https://amzn.to/3oOxHtE
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Ring Terminals, UL, Marine: https://amzn.to/3K0N3lw
Capacitor, 450V, 1000uF: https://amzn.to/3lTHopw
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Charge Controller used in this video (Victron 250/100): https://amzn.to/40k4kNz
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Harbor Freight Links, Not Affiliated:
6.6 Hp, 224cc, MAX: https://www.harborfreight.com/generators-engines/engines/66-hp-224cc-max-performance-ohv-horizontal-shaft-gas-engine-carb-57493.html
Band Saw: https://www.harborfreight.com/power-tools/power-saws/band-saws-scroll-saws/10-amp-deep-cut-variable-speed-band-saw-64194.html
Flux Core Welder: https://www.harborfreight.com/easy-flux-125-amp-welder-56355.html
Note: I have no affiliate with Harbor Freight.
Previous Video making a battery charging generator from a free treadmill motor: https://youtu.be/DaF6n-9RVT4
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