By Papa Bale · April 6, 2026
It's one of the most common questions in the pulse motor community: can a pulse motor actually charge a battery? The short answer is yes — under the right conditions, a Bedini-style pulse motor can charge a secondary battery using the back-EMF spike it generates every pulse cycle. But the complete answer requires some nuance about what "charging" means, how much energy is actually being transferred, and what the measurements say.
Every time the transistor in a pulse motor circuit cuts off current to the energizer coil, the collapsing magnetic field generates a voltage spike — back electromotive force (back-EMF). This spike can be many times higher than the supply voltage. A 12V input battery may produce 60V, 100V, or higher spikes depending on coil inductance and switching speed.
The standard Bedini SSG configuration takes advantage of this: a flyback diode routes the back-EMF spike not to ground (where it would be wasted as heat in a conventional circuit) but into a second battery — the "charging battery." Over time, these pulses deposit charge into the secondary battery.
Here's where things get interesting — and where honest measurement is critical. When builders first try pulse motor battery charging, they often see impressive voltage numbers on the secondary battery: 13V, 14V, even higher. This looks like a well-charged battery. But voltage alone doesn't tell the whole story.
High-voltage, low-current pulses can push a battery's terminal voltage up quickly — this is called surface charge. The battery reads "charged" on a voltmeter, but if you load it, the voltage collapses immediately because the charge is only skin-deep in the battery plates. True capacity recovery requires measurement under load.
When builders apply this rigorous approach, they typically find that pulse motor battery charging is real — energy does transfer to the secondary battery — but COP (output ÷ input) is less than 1. The input battery depletes faster than the output charges. This is consistent with normal physics; no known device creates energy from nothing.
Great question. There are several legitimate reasons why back-EMF charging is useful and interesting even if it doesn't violate physics:
Without a flyback recovery path, the back-EMF spike is absorbed by a protection diode and dissipated as heat — wasted. Routing it to a charging battery converts that wasted energy into something useful, improving overall system efficiency. Less heat, more charge. This is genuine and measurable.
John Bedini famously claimed his pulse charger could restore sulfated lead-acid batteries that conventional chargers couldn't revive. Many hobbyists report similar results. The high-voltage, short-duration pulses may help break down lead sulfate crystals on battery plates. This is a separate benefit from raw charging efficiency.
Understanding how a pulse motor interacts with batteries teaches you enormous amounts about electromagnetic induction, reactive power, battery behavior, and circuit design. Even if you're not trying to charge a battery "for free," the experiments are deeply educational.
Papa Bale's more recent experiments use a supercapacitor bank rather than a battery as the output storage. Supercapacitors accept charge more readily than batteries, don't care about the high-voltage spikes, and show voltage rise that's easier to measure and graph in real time. Starting from 1.5V cap bank input and watching it climb to 9V while pulling 220mA — as Papa Bale documented with his 26AWG litz wire coil — is concrete, measurable, and reproducible.
If you're setting up a charging experiment, consider starting with a supercapacitor bank. The results are faster, clearer, and less ambiguous than battery charging tests.
Yes, a pulse motor can charge batteries. The back-EMF recovery mechanism is real, the voltage rise on a secondary battery is real, and the effect is reproducible. What is not real — or at least not yet demonstrated with rigorous measurement — is overunity charging where the output exceeds the input. The interesting questions are not about free energy; they're about how efficiently you can transfer the available energy, and what else you can do with it along the way.
Papa Bale documents pulse motor charging experiments with real-time multimeter readings on YouTube. See the numbers, not just the theory.