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Decent.
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Prices may varyThis product ranks #8 of 20 in Jump Starter.Three above it ↓
Last reviewed June 1, 2026
TL;DR No third-party certification (no UL, ETL, or CE confirmed). The JNC660 claims 1,700 peak amps from a sealed lead-acid battery · broadly trusted by owners and a professional-shop standard, community evidence supports reliable starting of large-displacement gas and diesel engines, but the label claim has not been independently bench-verified. Prop 65 warning from lead (SLA battery) and ABS housing materials.
The JNC660 is a sealed lead-acid portable jump starter claiming 1,700 peak amps and 425 cranking amps, delivered through a 22Ah Clore PROFORMER SLA battery and a 46-inch #2 AWG welding cable rated to −40°C. The peak-amp label claim is not independently verified by third-party bench measurement · no Project Farm or equivalent test was found for this model. What is well-documented: the JNC660 is the de facto standard in US automotive repair shops and car dealerships, with community evidence from Bob Is The Oil Guy, Garage Journal, and owner reviews consistently reporting successful starts of V8 engines, diesel trucks, and farm equipment. Build longevity is exceptional · 5·15 year ownership is common in community data, with multiple 20-year ownership accounts on the Clore Automotive blog. Secondary features include a 12V DC accessory outlet and an analog voltmeter for charge-status indication. Maintenance charging every three months is required to prevent battery sulfation; units that are maintained properly last far longer than lithium alternatives in the same use category.
Best for drivers or shops that need to start large-displacement gas engines, diesel trucks, or heavy equipment · particularly in cold climates where lithium-ion jump starters lose capacity below freezing. The SLA design delivers high sustained current without the cold-temperature drop that affects lithium packs. Skip if portability matters: at 18 lbs, the JNC660 is significantly heavier than compact lithium alternatives, and the quarterly maintenance charging requirement makes it a poor fit for drivers who want to store a jump starter in a glovebox and forget it.
No third-party electrical safety certification was confirmed · no UL Product iQ or ETL database entry found as of 2026-05-13. No active CPSC recall exists. The sealed lead-acid battery carries a Prop 65 warning for lead and ABS housing materials; normal external use as a jump starter does not create a direct exposure pathway. Sealed lead-acid batteries have near-universal US recycling infrastructure · auto parts stores and scrap yards accept SLA units, and the manual explicitly requires recycling.
No certification was confirmed as of the scoring date (2026-05-13). A UL Product iQ database search and a review of the product manual and manufacturer product page found no UL, ETL, or CE mark referenced. CE marking status is unknown. The JNC660 is a long-market US professional product without a third-party electrical safety certification that can be confirmed through publicly accessible databases.
Community evidence · including a large base of highly rated owner reviews, Bob Is The Oil Guy forum threads, and the Garage Journal · consistently documents successful starts of V8 engines, diesel trucks, and farm equipment. early owner feedback documents starting a 4.2L motor without a battery present. The 1,700 peak amp and 425 cranking amp label claims have not been independently bench-verified; these are community pass/fail reports rather than measured amp-delivery data.
Manufacturer instructions specify: charge when first purchased, immediately after each use, and every three months during storage. The sealed lead-acid battery self-discharges more slowly than lithium-ion but requires periodic maintenance charging to prevent sulfation · irreversible capacity loss from prolonged discharge. Multiple community reviews document units lasting 5·15+ years with proper maintenance.
The Prop 65 warning in the product manual names lead (from the sealed lead-acid battery), vinyl chloride, styrene, and acrylonitrile (from the ABS plastic housing) as substances known to the State of California to cause cancer, birth defects, or reproductive harm. Normal external use of the unit as a jump starter does not create a direct exposure pathway to these substances; the warning applies to the materials contained within the device.
The JNC660 uses a 22Ah sealed lead-acid battery, making it significantly heavier (18 lbs) than compact lithium units. The SLA chemistry provides high sustained peak current for large-engine starting and is less vulnerable to cold-temperature capacity loss than lithium-ion. The trade-off is weight and the need for quarterly maintenance charging. Modern lithium units are lighter, more portable, and require less maintenance but may struggle with sustained cranking on large-displacement engines in cold weather.
Marketing copy from Clore Automotive, via Amazon. Not editorial.
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