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Prices may varyThis product ranks #17 of 20 in Jump Starter.Three above it ↓
Last reviewed June 21, 2026
TL;DR No third-party electrical safety certification confirmed (CE, FCC, and UN38.3 marks present; no UL or ETL listing found). The RJ31 claims 1500A peak for 12V engines up to 6L gas and 4.5L diesel · the lowest peak-amp rating in the Rexing lineup, and the label claim has not been independently bench-tested. The built-in 150 PSI air compressor and QC 3.0 USB ports add real utility for drivers who want one device covering multiple roadside needs. CPSC recall status could not be verified at time of scoring (cpsc.gov blocked) · verify at cpsc.gov before purchase.
The RJ31 is a 1500A 12V jump starter that integrates a 150 PSI air compressor, QC 3.0 USB charging ports, and a 150-lumen LED flashlight into a single compact unit. The 1500A peak rating is the weakest in the Rexing jump-starter lineup and sits at the lower end of its price tier compared with competing brands. The claim has not been independently verified by any third-party bench-measurement source. Community evidence is very limited: two brand-direct reviews were on file at time of scoring, one of which reported successful repeated starting with charge to spare. The air compressor and air blower functions are genuine differentiators: a standard passenger car or SUV tire can be inflated to 30 to 35 PSI without a separate pump, and the blower mode handles dust removal in vehicle interiors. CE, FCC, and UN38.3 marks are confirmed from the product's certification infographic; no UL or ETL listing was found. The manufacturer claims the 12000mAh battery holds a usable charge for up to 2 years under storage; this has not been independently verified.
The RJ31 suits drivers of passenger cars, light-duty SUVs, and motorcycles who want one trunk bag to cover a dead battery, a low tire, and phone charging. The 150 PSI inflator is the primary differentiation from single-function jump starters at the same price. Skip it if starting a diesel engine above 4.5L or a large-displacement V8 truck is the use case · step up to a unit rated 2,000A or above. Buyers who prioritize third-party electrical certification (UL/ETL) should look at certified alternatives; the RJ31 carries CE only.
CE, FCC, and UN38.3 certifications are confirmed from product imagery; no UL or ETL electrical safety listing has been confirmed for this model. Battery chemistry is standard Li-ion; no documented thermal-runaway incidents for the RJ31. CPSC recall database was inaccessible at time of scoring · verify at cpsc.gov before purchase. Li-ion batteries are recyclable via Call2Recycle drop-off locations at Home Depot, Lowe's, and Staples; no Rexing manufacturer take-back program is documented.
No UL listing has been confirmed for the RJ31. The product page shows CE, FCC, and UN38.3 certification marks · no UL or ETL mark appears anywhere on the product or its documentation. CE is an EU-market import certification; it is not equivalent to UL or ETL third-party lab testing. If a UL Product iQ database entry is ever confirmed for this model, the safety certification score will be updated.
Yes. The RJ31 includes a built-in air compressor rated to 150 PSI, which is sufficient for standard passenger car and SUV tires (typically 30 to 35 PSI). The unit functions as both a jump starter and a tire inflator from a single rechargeable device, with no separate compressor needed.
The product spec sheet shows a 4.5L diesel engine rating. The product title uses '3L diesel,' but the detailed specification infographic in the product listing shows 4.5L diesel · the more specific source. For gas engines, the rating is up to 6L.
Yes. The RJ31 includes a USB-C port labeled QC 3.0 for both charging the device and charging other devices via USB-C. The confirmed output spec is 5V/2A. It is not a USB-C Power Delivery port · it does not fast-charge laptops at 18W+ like PD-capable units do.
Rexing's product listing claims the unit stays charged for up to 2 years under normal storage conditions. Independent community verification of this claim is limited · only 2 brand-direct reviews were available at time of scoring. The claim is listed as manufacturer-stated and has not been confirmed by independent long-term owners.
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