If you've spent any time shopping for 18650 cells for a vape mod, a flashlight, or a DIY battery pack, you've probably run into LG's HE lineup. The HE2 and HE4 show up on almost every supplier's shelf, they're priced close to each other, and on paper they look nearly identical. So which one should actually go in your cart?
Short answer: it depends on how you use the battery, not just what the label says. Here's what actually separates these two cells, based on manufacturer datasheets and independent bench testing — not marketing copy.
Why These Two Cells Keep Coming Up
The HE2 was LG's first widely adopted 20A high-drain cell, released around 2013–2014 and built on an NMC (nickel-manganese-cobalt) chemistry with a silicon-oxide-blended anode. It quickly became a go-to choice for vapers and flashlight builders who needed steady current without the bulk of a larger cell.
The HE4 followed a year or so later as LG's refinement of that same 2500mAh, 20A platform. It's not a different capacity class — it's an updated version aimed at fixing some of the wear-and-tear issues high-drain users were running into with the HE2. That's really the core of the comparison: same numbers on the wrapper, different engineering underneath.
Spec-by-Spec Comparison
| Spec | LG HE2 | LG HE4 |
|---|---|---|
| Nominal Capacity | 2,500mAh | 2,500mAh |
| Nominal Voltage | 3.6V | 3.6V |
| Max Continuous Discharge | 20A | 20A |
| Discharge Cutoff Voltage | 2.0V | 2.5V |
| Cycle Life (60-70% capacity retained) | 300 cycles @ 10A, 200 cycles @ 15A | 300 cycles @ 10A, 200 cycles @ 20A |
| Chemistry | NMC / graphite + SiO | NMC (similar formulation, revised) |
| Weight | ~48g | ~47g |
The capacity, voltage, and headline discharge rating are identical. The real difference is in that cycle life row. LG only rates the HE2 for 200 cycles when it's pushed to 15A — the datasheet doesn't even list a 20A cycle-life figure for it. The HE4, on the other hand, is rated for 200 cycles at a full 20A. In plain terms: if you're regularly running these cells at their maximum discharge rate, the HE4 is built to hold up longer before it starts losing meaningful capacity.
There's also a small but practical difference in the cutoff voltage. The HE2 is tested down to 2.0V, while the HE4 cuts off at 2.5V. That half-volt gap can account for 50–100mAh of the "extra" capacity you sometimes see quoted for one cell over the other in casual comparisons — it's a testing artifact more than a real-world advantage.
How They Actually Perform on the Bench
Independent testers (notably the ECF and CandlePowerForums communities, who've run both cells through controlled discharge tests for years) found results that don't perfectly match the spec sheet story.
At 10A, both cells deliver close to their full rated capacity — around 2,375–2,400mAh, which is excellent for a 2,500mAh-class cell. At 20A, both hold their 20A continuous rating, but neither is what you'd call cool-running. The HE2 has been described as a cell that "gets pretty hot" under sustained 20A loads, while the HE4 tends to run a few degrees cooler in the same conditions, though it also shows slightly less capacity than some newer competing cells (like the Samsung 25R5) when pushed to 20A.
Peak/pulse current is another area where people get confused by marketing. Some resellers label these cells "35A" or "40A," but that's a pulse rating, not a continuous one. LG's own documentation treats 20A as the continuous ceiling for both the HE2 and HE4. Running either cell at 30A+ for any extended period will spike the surface temperature well past 80°C — testers have recorded the HE2 hitting the low 90s°C under 25A loads, which is firmly in "don't do this regularly" territory.
Which One Fits Your Device?
This is really the question that matters more than any spec sheet.
- If you're vaping sub-ohm at 15-20A, running a mechanical mod, or building packs for power tools that draw hard and often, the HE4's better high-drain cycle life gives it a practical edge. You'll likely get more usable life out of the cell before it degrades.
- If your device draws current in short bursts rather than sustained pulls — a flashlight on turbo mode for a few seconds at a time, for example — the HE2's slightly lower internal resistance in some bench tests can translate to marginally better voltage stability under those brief loads.
- If capacity matters more to you than raw discharge headroom, neither of these is really the ideal pick — that's where a cell like the HG2 comes in (more on that below).
For most everyday users, the difference between HE2 and HE4 is small enough that either will work fine. The HE4 is the safer long-term bet if you're discharging hard and often; the HE2 remains a solid, proven option if your usage is lighter or more intermittent.
Pros, Cons, and What Users Actually Say
LG HE2
- Pros: Proven track record, widely available, slightly better voltage sag control in light bench tests, good value
- Cons: Runs hot under sustained 20A loads, shorter high-drain cycle life on paper, older design
LG HE4
- Pros: Better rated cycle life at max discharge, marginally cooler operation at high current, still 2,500mAh/20A performance
- Cons: Slightly lower capacity than newer competing cells at 20A, similar heat concerns as any 20A cell pushed to its limit
Users on vaping and flashlight forums generally describe both cells as reliable, no-surprises performers — nobody's reporting them as unsafe when used within their rated limits. The most common feedback is that people can't tell much of a real-world difference between the two in day-to-day use, which lines up with how close the bench numbers actually are. The complaints that do show up are almost always tied to counterfeit or relabeled cells bought from unverified sellers, not the genuine LG product.
How the HE2/HE4 Compare to the LG HG2
If your priority shifts from pure discharge rate to runtime, the HG2 is worth a look. It shares the same 20A continuous discharge rating as the HE2 and HE4, but bumps capacity up to 3,000mAh — roughly 20% more energy per cell. Independent testing puts its real-world capacity closer to 2,900-2,960mAh, which still comfortably beats both HE-series cells.
The trade-off is that the HG2 runs a bit warmer at its rated 20A ceiling due to the higher energy density packed into the same 18650 form factor, and its cycle life is rated similarly to the HE4 (300 @ 10A, 200 @ 20A). For builds where you want both solid discharge performance and longer runtime — vape mods used for extended sessions, or power packs where swapping cells often isn't convenient — the HG2 is a genuinely different tool, not just a bigger number on the label.
Bottom Line: Which Should You Buy?
- Choose the LG HE2 if you want a proven, budget-friendly high-drain cell for moderate or intermittent high-current use.
- Choose the LG HE4 if you're discharging hard and often and want better long-term cycle durability at 20A.
- Choose the LG HG2 if runtime and capacity matter as much as discharge rate to you.
All three are in stock and ready to ship — check out our LG HE2, HE4, and HG2 listings to compare current pricing and pick the cell that matches how you actually use your device. If you're not sure which one fits your setup, our team is happy to help you figure it out before you order.