What Happens When You Overcharge a LiPo Battery? A Real FPV Fire You Should Learn From

Most FPV and RC pilots know, at least in theory, that you should never overcharge a LiPo. But theory is one thing. Watching a fully loaded pack erupt into a fireball right in front of you is something else entirely.

Recently, a group of pilots decided to spend a “normal day at the studio” deliberately pushing a couple of fresh LiPo packs way beyond their rated voltage—on camera. One pack burst into flames on the bench. Another one was strapped to a quad and flown hard while still overvolted. The footage is wild, but the lessons behind it are even more important.

A normal FPV day that went sideways

The day didn’t start with drama. The crew just rolled into the studio, unpacked gear, and tossed around ideas for what to film. Then someone suggested the kind of idea that sounds funny at first and terrifying in hindsight: “What if we overcharge a LiPo pack and see what happens?”

On paper, it sounded like a controlled experiment. Brand new packs. Indoor setup. Fire extinguishers. Cameras rolling. Nobody really believed anything catastrophic would happen. After all, how bad can it be to push a fresh pack a bit over its rated voltage, just this one time, in a “safe” environment?

Within a few minutes, everyone’s attitude changed completely.

Setting up the experiment: cardboard, chargers, and misplaced confidence

They did at least try to be “responsible” about it. Before touching a battery, the team went out and bought fire extinguishers. They laid down cardboard and set the packs on a wooden table, believing that if anything went wrong, it would be easier to manage the fire there than on the cluttered studio floor.

Two packs went on the chargers: a 4S and a 6S. The plan was to bring them up to normal full charge first, then keep pushing the voltage higher. Everyone stood around watching the display creep up while pretending to be relaxed, joking about how “it’ll probably be fine.”

But LiPos don’t care about jokes, or about the fact that this is “just content” for a video. They only care about chemistry and physics.

The moment everything went wrong

As the voltage crept past normal values, the signs started showing:

• The pack began to feel warm to the touch.
• The casing started to swell and puff.
• There were strange noises and a faint chemical smell.

At that point, everyone knew they were in the danger zone. Someone reached in to feel the pack, someone else hesitated with the charger, and then it happened: the battery violently vented and turned into a spray of flames and smoke.

The fireball shot up faster than anyone expected. For a moment, it looked like the entire table—and everything on and around it—might be lost. Fire extinguishers finally did their job, but not before everyone got a harsh, physical reminder: an abused LiPo doesn’t just “fail.” It explodes with energy that was meant to keep your aircraft in the air.

Flying on an overcharged pack: pushing the limit in the air

As if one bench fire wasn’t enough, the team decided to take the experiment further. Another pack was charged well beyond normal levels and mounted on an FPV quad. The idea was to see how an overcharged pack behaves in flight, and whether they could “use up” the extra voltage in the air before something disastrous happened.

The voltage reading was already way past the usual comfort zone. Yet the quad armed just fine. Once in the air, it felt wrong in all the ways that look impressive in a video and horrifying if it’s your own build:

• The quad had punch well beyond what a normal 4S should deliver.
• The motors were being fed voltage they were never designed to see.
• The ESC and wiring were living on borrowed time.

At one point, one of the pilots literally held another pilot’s finger on full throttle, forcing the quad to stay pinned while the pack was hammered as hard as possible. The voltage sagged aggressively, but the damage was already done. By the time the quad came back in, the battery was badly stressed, physically chewed up, and effectively destroyed.

It made for exciting footage. It would make for a terrible day if that pack had decided to fail mid-arm while someone was leaning over the quad to plug it in.

What this really proves about LiPo safety

The experiment didn’t teach experienced pilots anything “new” about chemistry. What it did do is put a very visual, very loud confirmation on things many people already know but don’t always take seriously:

• LiPo labels are not suggestions. Voltage ratings exist for a reason. Going far beyond them will eventually end in thermal runaway.
• Puffing is not cosmetic. When a pack starts to swell, it’s telling you that gas is building up inside. That’s a warning sign, not something to ignore.
• Fresh batteries are not invincible. Being brand new doesn’t make a pack more tolerant of abuse. In some ways, it just means there’s more stored energy to release at once.
• “Controlled” experiments can get out of control fast. Even with cameras rolling and extinguishers nearby, the fire still caught people off guard.

If a group of experienced pilots can be surprised by how violent a LiPo fire is, it’s very easy for a casual user at home to underestimate the same risks.

How far is “too far” for LiPo voltage?

Every chemist and engineer will have their own highly technical way to explain it, but for everyday flying there’s a simple rule of thumb:

• For standard LiPo packs, 4.20V per cell is full.
• For LiHV packs that are specifically designed for it, 4.35V per cell is full.
• Anything substantially beyond that is not “extra performance.” It’s damage building up inside the cell.

In the video experiment, the pack was pushed significantly over 5V per cell. At that point, you’re no longer “charging a battery.” You’re forcing it into a runaway condition where heat, pressure, and internal reactions all start to feed on each other.

The key takeaway is simple: if your charger, pack, or routine suggests going above the manufacturer’s specified voltage, that’s not an upgrade—it’s a hazard.

Practical LiPo charging safety tips from this experiment

Stripping away the jokes and shock value, there are several practical reminders that every FPV and RC pilot can take from this kind of test:

• Use a modern, reliable charger. Don’t bypass safety features or trick the charger into thinking your pack is something it isn’t.
• Always balance charge. Keeping cells even is one of the best defenses against a weak cell turning into a problem.
• Pay attention to heat. If a pack is getting unusually warm while charging, stop and investigate.
• Never leave charging packs unattended. Especially not indoors around flammable clutter.
• Retire damaged or puffed packs. If the battery swells, vents, or smells odd, it’s earned its retirement.

Most experienced pilots already know these points. The problem is that they’re easy to forget when nothing has gone wrong yet. Watching a pack erupt on a bench is a powerful reminder of why the rules exist in the first place.

Why a LiPo safe bag is a simple but meaningful upgrade

No accessory can completely remove the risk of a LiPo failure, but some gear makes a very real difference in how contained that failure is. One of the most straightforward upgrades is a proper fire-resistant storage and charging bag designed for LiPo packs.

A good LiPo safe bag won’t magically make a bad pack good again, but it can:

• Help contain flames and hot debris if a pack vents or ignites.
• Reduce the chance of surrounding items catching fire.
• Give you crucial extra seconds to react with a fire extinguisher.

If you’re routinely charging indoors, near your workbench, computer, or radio gear, a dedicated bag is one of the easiest safety layers you can add. You can find a purpose-built option like the CNHL LiPo safe fireproof and explosion-resistant charge & storage bag , which is designed to be used both while charging and while storing packs between sessions.

It’s not about being paranoid. It’s about respecting how much energy a LiPo carries and giving yourself a margin of safety if something ever does go wrong.

Where responsible LiPo performance really comes from

The video experiment shows the ugly side of pushing a battery far beyond its limits. In real flying, performance doesn’t come from abusing chemistry. It comes from using the right pack, within its specs, and building a system that works as a whole.

For most FPV rigs, that means:

• Selecting a pack with appropriate C rating and capacity for your setup.
• Staying within the manufacturer’s recommended voltage range.
• Giving the pack reasonable cooldown time between hard flights.
• Storing packs at storage voltage when they won’t be used for a while.

Brands that take their cell matching and quality control seriously focus on delivering consistent voltage under load, not chasing unsafe numbers on a charger screen. That’s where true performance lives—inside the intended operating window, not beyond it.

FAQ: Common questions after seeing a LiPo fire

“If my pack puffed a little during a hard session, is it automatically trash?”

Not every tiny change in shape means a pack is done, but obvious or repeated puffing is a serious warning sign. If a pack feels noticeably swollen, stays that way after cooling, or has a strange sweet or chemical smell, it’s safer to retire it than to gamble on one more flight.

“Can I safely push my packs to 4.25V or 4.3V per cell for more punch?”

For standard LiPos, anything beyond 4.20V per cell is outside the intended design range. A few extra hundredths of a volt will not transform your flying, but over time it can degrade the pack and increase risk. If you want higher end-of-charge voltage, use LiHV packs that are specifically rated for 4.35V and charge them accordingly.

“Is it okay to charge in my living room if I’m in the same room watching?”

Being present is better than leaving packs unattended, but it’s still wise to control the environment. Charging on a nonflammable surface, inside a LiPo safe bag , with a fire extinguisher nearby, is a much better setup than tossing them on the couch or a wooden shelf.

“Do brand new LiPos handle stress better than old ones?”

New packs generally have lower internal resistance and better performance, but that doesn’t make them more tolerant of abuse like overcharging or physical damage. In fact, because they can deliver more current, they often release more energy when something goes wrong. Treat new and old packs with the same level of respect.

Final thoughts: respect the chemistry, enjoy the hobby

Watching someone else intentionally overcharge a LiPo until it explodes is entertaining in a controlled setting, but the only reason it’s fun to watch is because it’s not happening in your own workshop.

The lesson is clear: LiPos are incredible tools when used correctly, and dangerous when abused. Staying within proper voltage limits, charging with care, and adding simple protections like a LiPo safe bag all stack the odds in your favor.

Fly hard, experiment with builds, chase that perfect line—but give the batteries that power it all the respect they deserve.

For pilots who want dependable power without pushing their packs beyond safe limits, there's a full range of FPV-ready batteries designed for consistent performance. You can find them here: FPV drone batteries .