GOOLOO GT4000 vs GT4000S: What’s the Difference?

You pull up two product listings that look almost identical. Same brand, same model number — just one letter apart. I’m Alex Rahman, and after digging into both the GOOLOO GT4000 and GT4000S jump starters, I can tell you the difference comes down to one feature that most buyers never ask about — until they’re stranded in the cold.

Here’s what changes between these two models, what stays the same, and which one you should actually buy.

---

How Do the GOOLOO GT4000 and GT4000S Compare Side by Side?

Here’s a full side-by-side look at both models. Most specs are identical — but two numbers stand out.

Both models share an identical power output, battery size, and fast-charging system. The GT4000’s pre-heating tech and heavier build are the only meaningful gaps.

So if you live somewhere with mild winters, the specs above might make the GT4000S look like the obvious pick. But the cold-weather gap is bigger than it first appears — and we’ll cover that next.

---

What Do the GT4000 and GT4000S Have in Common?

Both the GT4000 and GT4000S share the same core engine. They both deliver 4000 peak cranking amps — enough to start gas engines up to 12.0L or diesel engines up to 10.0L. Most drivers will never need more power than either model provides.

The battery inside both units is identical: 24,000mAh at 3.7V, equal to 88.8 watt-hours. That’s enough for multiple jump starts on one charge. It also means both hold a charge for up to 24 months in standby — so you can keep it in your trunk and forget about it until you need it.

Here’s what else they share:

According to Consumer Reports’ jump starter buying guide, temperature tolerance is one of the most overlooked specs when buying a portable jump starter — and it’s exactly where these two models diverge.

Now let’s get to what actually separates them.

---

What Is the Real Difference Between the GT4000 and GT4000S?

The GT4000 includes Intelligent Pre-Heating Technology. The GT4000S does not. That’s it — that’s the entire functional difference between these two jump starters.

But here’s why that matters more than it sounds.

How Pre-Heating Technology Works in the GT4000

Lithium-ion batteries lose efficiency fast in cold weather. In temperatures near -4°F, a lithium battery can deliver a fraction of its rated power. That means a jump starter rated at 4000A might not actually deliver 4000A when it’s freezing outside.

The GT4000’s pre-heating system warms the internal lithium cells before sending power to the vehicle battery. This happens automatically. The unit reaches full operating temperature without any waiting time, even at -40°F (-40°C).

The GT4000S skips this system entirely. Its rated minimum operating temperature is -4°F (-20°C). Below that, the internal cells aren’t warmed — and cranking performance can drop well before you hit that lower limit.

What About the Weight Difference?

There’s a second gap that buyers often miss: the GT4000 weighs 4.93 lbs, while the GT4000S weighs just 2.31 lbs. That’s more than 2.6 lbs lighter — despite identical peak amps and battery capacity.

This weight difference likely comes from the pre-heating components inside the GT4000. The GT4000S trades those components for a lighter build while keeping the same power output. So if you’re after a compact, lightweight unit to carry in a bag or glove compartment, the GT4000S wins on portability.

Both units share the same physical dimensions — 9.05″ x 3.93″ x 2.12″ — so the weight difference doesn’t change the footprint. It just changes how heavy the unit feels in your hand.

For a deeper look at how these models fit into GOOLOO’s full lineup, see our guide on the best GOOLOO jump starter across all models.

---

Is the GT4000 or GT4000S Better for Your Situation?

Both units cost the same. So this decision comes down to one question: where do you live, and how cold does it get?

If you’re unsure whether either model suits a specific vehicle, our guide to what a GOOLOO jump starter is covers compatibility in more detail. You can also check the GOOLOO GP4000 review if you’re considering the lower-priced GP-series as an alternative.

---

What Most People Get Wrong About the GT4000 and GT4000S

Most buyers assume the “S” means a better or newer model — like a software update on a phone. It doesn’t. The GT4000S is a simplified version of the GT4000, not an upgrade. It removes the pre-heating system, which makes it lighter and — in some markets — slightly cheaper.

A second wrong belief: that 4000 peak amps is the same in all conditions. It isn’t. Lithium batteries deliver less power in cold temperatures, even before hitting their minimum rated threshold. The GT4000 actively compensates for this with its heating system. The GT4000S relies on ambient temperature to stay within its operating range.

Third: many buyers think the GT4000S can’t charge laptops as fast. Wrong — both models include the same 100W PD two-way charging system. The GT4000S can charge a laptop at 65W output, just like the GT4000. The fast-charging specs are identical across the board.

---

Conclusion

The GOOLOO GT4000 and GT4000S are the same jump starter in almost every way. Same power, same battery, same fast charging. The GT4000 adds one thing: cold-weather pre-heating down to -40°F. The GT4000S drops that feature — and 2.6 lbs — in return.

If you live somewhere cold, buy the GT4000. If your winters stay above -4°F, the GT4000S gives you the same performance in a lighter, easier-to-carry package.

One thing to do right now: Check your region’s average January low temperature. If it ever dips below -4°F, order the GT4000. If not, the GT4000S is the better everyday carry.

---

Frequently Asked Questions