Hulkman Alpha85S Review

The dirty secret of lithium jump starters is the operating-temperature line in the spec sheet. NOCO rates the GB40, GB70, and GBX155 to -4°F; GOOLOO says the same. Below that, a pack that's been in a frozen truck may not deliver enough current to turn a cold engine, which is the precise moment you bought it for. The standard advice — keep the pack in the cabin, or bring it inside overnight — works, but it depends on you remembering. Hulkman's answer in the Alpha85S is a heating element and a thermostat: below 32°F the pack warms its own cell first, then lights a READY indicator, and the company rates the whole unit to operate at -40°F.

The rest of the package is strong enough that the cold feature isn't the only reason to buy it. The 74Wh cell is more than double the capacity of NOCO's 2,000A packs, which shows up as more attempts per charge — AutoGuide's review reported seven starts of a fully dead Subaru Forester using about 40% of the pack, and two cranks of a 6.5L diesel before the thermal protection stepped in. The 3.3-inch display replaces the usual row of LEDs with actual words and numbers, which is worth a lot when you're troubleshooting in the dark with gloves on. It recharges over 65W USB-C in roughly ninety minutes, and the 12V barrel output is rated to 150W, enough for a plug-in tire inflator.

Be clear-eyed about the trade-offs. Pre-heating takes up to a minute and spends some of the charge, so in deep cold you wait before you crank. Hulkman has been around a few years, not a few decades, and its 2,000A figure is a manufacturer rating like everyone else's — we'd treat the 8.5L gas number as generous. The USB-C port is 65W in but only 18W out, so it's a phone charger, not a laptop charger like the GBX155. And a handful of owners report that a truly flat battery needs a manual boost step to be recognized. None of that changes the core proposition: if your car sleeps outside where -20°F happens, this is the one jump starter built for that morning.