Small engine driven battery charging alternator.
Has anyone tried using a small engine driven automotive alternator for occasional battery charging?
Taking a single phase generator that makes 120 or 240 volt single phase power then stepping it down and rectifying it to a much lower voltage and trying to smooth out the AC pluses seems pretty inefficient.
If you were to generate the same amount of electrical power with 3 phase the engine could do it with 11% less engine torque. Then creating it only at the voltage you needed and charging batteries instead of trying to step it up and down and smooth it out sounds so much more efficient.
To buy a good generator and battery charge and generator costs a lot of money. Everyone raves about the inverter generators being so efficient then cries when they see the price tag, because they are variable speed and the sourced power is 3 phase. A alternator based DC generator charger does the same thing.
For a 12V system simply just engine driving a common alternator with a small engine and belt drive would give you what you need.
To make 24V you would need to buy a 24V alternator or take a super common alternator available with 12 and 24 volt versions and swap in the 24V regulator. Such as could be done with an SI-10 or SI-12.
48 volts would be a little more difficult. I think you would have to take apart the alternator, remove the rectifier because its only intended for 24v max, wire to an external one, provide 12vdc to power the voltage regulator and put a voltage divider on the V-sense to trick the alternator into producing the roughly 55VDC you would want to charge a 48 volt system.
It sounds a lot cheaper than buying a generator and battery charger for emergency charging.
What do you think?
Solar hybrid gasoline generator, 7kw gas, 180 watts of solar, Morningstar 15 amp MPPT, group 31 AGM, 900 watt kisae inverter.
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