The Conductivity of Brute Force: Engineering Analysis of the Clore JNC660

In the hierarchy of portable power, the Clore Automotive Jump-N-Carry JNC660 occupies a distinct classification. It is not a consumer accessory designed for occasional peace of mind; it is an industrial implement forged for the repeated delivery of high-amperage current. Weighing 18 pounds and lacking the digital refinements of modern power banks, its design philosophy is rooted in the immutable laws of electrical conductivity and chemical thermodynamics.

The device claims 1700 Peak Amps and, more importantly, 425 Cranking Amps. While these numbers are printed on the box, their realization in the real world depends entirely on the delivery system. A battery is only as powerful as the wire that connects it to the load. The JNC660 distinguishes itself not just by what is inside the box (the battery), but by how it overcomes the resistance of the connection (the cables). This analysis dissects the physics of the JNC660’s architecture to explain why it remains the standard for tow trucks and fleet mechanics despite the influx of lighter lithium alternatives.

The Physics of Cabling: #2 AWG vs. The World

Geometric Compensation for Length

The most defining feature of the JNC660 is its cabling: 46 inches of #2 AWG (American Wire Gauge) copper.
To the layperson, “long cables” are a convenience feature. To the electrical engineer, they are a liability that must be engineered around. Every inch of wire adds electrical resistance ($R$). According to Ohm’s Law ($V = I \times R$), as resistance increases, voltage drops. * The Problem: Extending cables from 20 inches (standard) to 46 inches more than doubles the resistance. If the wire gauge remained the same (e.g., #4 AWG), the voltage drop at 400 Amps would be catastrophic, delivering insufficient voltage to the starter motor. * The Solution: Clore engineers increased the cross-sectional area of the conductor. #2 AWG wire has a cross-sectional area of approximately 33.6 mm², compared to 21.2 mm² for #4 AWG. This 58% increase in copper mass reduces resistance per foot, effectively neutralizing the penalty of the longer length.

This geometric calculation ensures that the potential difference generated at the battery terminals is preserved at the clamps. When starting a diesel engine requiring 400A, a voltage drop of even 1.0V can mean the difference between a slow crank and a start. The JNC660’s massive cables act as a lossless conduit, allowing the user to place the unit on the ground (thanks to the 46” reach) without sacrificing the electrical punch required for ignition.

The Chemistry of the PROFORMER Battery

Power Density vs. Energy Density

The 18-pound mass of the JNC660 comes primarily from its 22Ah Clore PROFORMER battery. This is a sealed Lead-Acid AGM (Absorbed Glass Mat) unit.
In the debate between Lead-Acid and Lithium-Ion, confusion often arises between Energy Density (how much energy is stored per kg) and Power Density (how fast that energy can be released). * Lithium: High Energy Density. Great for charging phones or running laptops for hours. * Lead-Acid (AGM): High Power Density. Excellent for dumping massive current in seconds.

The PROFORMER battery is engineered specifically for High-Rate Discharge. Its internal plate structure maximizes surface area to facilitate rapid ion exchange. This allows it to sustain 425 Cranking Amps for extended durations. Unlike lithium cells, which heat up rapidly and face internal resistance spikes under such loads, the sheer thermal mass of the lead plates absorbs the heat generated during the cranking cycle ($I^2R$ losses), preventing voltage sag and allowing for longer, sustained cranking attempts—critical for priming diesel fuel systems.

The Low-Temperature Advantage

User reviews frequently mention the JNC660’s superiority in cold weather (e.g., Mcgyver210 starting a Mitsubishi Turbo Diesel). This is due to the fundamental difference in control logic between AGM and Lithium.
Lithium batteries require a Battery Management System (BMS) to operate safely. In extreme cold (-20°F), lithium ion mobility slows, and internal resistance rises. The BMS detects this and often restricts current or shuts down completely to prevent lithium plating or cell damage.
The JNC660 has No BMS. It is an analog chemical reactor. Even when frozen, it will attempt to deliver current. While its capacity drops in the cold, it does not “refuse” to work. It forces current through the starter motor, relying on the brute force of 22Ah of capacity to overcome the viscosity of cold engine oil. For emergency responders, this “dumb” reliability is a strategic asset.

The “Hot Jaw” Mechanical Interface

Penetrating the Oxide Layer

Current delivery fails at the point of highest resistance: the connection to the vehicle battery. Lead battery terminals oxidize, forming a gray layer of lead sulfate/oxide which is electrically insulating.

The JNC660 utilizes Industrial Grade Hot Jaw Clamps.
1. Spring Tension: The clamps feature a high-tension industrial spring, significantly stronger than consumer-grade clips.
2. Tooth Geometry: The teeth are sharp and angled.
3. Mechanism: When applied, the high tension forces the sharp teeth to bite through the soft lead oxide layer, establishing a metal-to-metal contact with the conductive lead post underneath.
4. Live Jaws: Both sides of the clamp are electrically connected (via a braided copper strap). This doubles the contact area, halving the contact resistance.

This mechanical engineering ensures that the 425 Amps flow into the battery, rather than generating an arc or heating up the clamp due to poor contact.

Thermal Durability and Case Design

The casing of the JNC660 is high-impact polyethylene, described as “impervious to shop fluids.” In a professional environment, exposure to brake fluid, oil, and gasoline is inevitable. Many consumer plastics degrade or become brittle upon contact with hydrocarbons. The JNC660’s shell is designed to resist chemical attack.
Furthermore, the battery inside is Vibration Resistant. AGM technology compresses the plates within fiberglass mats. This compression prevents the plates from shedding active material during the shocks and drops inherent to workshop use. A standard flooded battery would suffer from plate collapse or internal shorts under similar abuse.

In conclusion, the Clore JNC660 is an exercise in purpose-built engineering. It accepts the penalty of weight (18 lbs) to secure the advantages of conductivity (#2 AWG) and chemical resilience (AGM). It is a tool designed not for convenience, but for the certainty of execution.