How many times can the Sigma 35 charge a phone?

At 10,000mAh, the Sigma 35 carries enough capacity to fully charge most modern smartphones twice over. Actual charge count depends on the phone's battery size and how much charge remains in the power bank at the start.

Does the Sigma 35 come with a cable?

Yes. It ships with Type-C and Lightning cables built directly into the unit, so no separate cable is needed. The Type-C end covers Android devices, and the Lightning end covers iPhones.

Is the Sigma 35 allowed on flights in India?

Yes. At 37Wh it sits well within IATA's 100Wh carry-on limit and travels on every airline without prior approval. Full flight rules are available at Airline Rules for Laptop Power Banks: https://www.gravlspace.com/blogs/news/power-bank-rules-flights-india-2026

Can the Sigma 35 charge a laptop?

No. At 35W output it is not suited to laptop charging, since most laptops draw more than 35W under active use and require higher output to charge rather than slow discharge. For laptop charging, start with the GRAVL Axis 67 at 67W: https://www.gravlspace.com/products/gravl-axis-67

What is the warranty on the Sigma 35?

4 years total: 1 year unconditional from the date of purchase, plus 3 years on the battery once the product is registered at https://www.gravlspace.com/pages/register-warranty. Full terms are available at https://www.gravlspace.com/pages/warranty

Semi Solid Powerbank

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The GRAVL Semi-Solid Powerbank collection is built around a single idea: the battery inside your power bank matters more than the case around it. Most power banks on the market still use liquid lithium-ion cells, a design that hasn't fundamentally changed in over a decade. GRAVL's semi-solid state battery replaces that flammable liquid electrolyte with a partially solidified one, dramatically reducing the risk of thermal runaway, the chain reaction responsible for most power bank fires. The result is a power bank that is engineered to be safe from the cell up, not just the casing out.

This isn't a marketing claim. It's chemistry. Semi-solid cells run cooler, degrade more slowly, and hold their charge more consistently over years of daily use, which is why every product in this collection is backed by a 4-Year Warranty. It's also why GRAVL's semi-solid technology is IATA-compliant and safe for cabin carry on every domestic and international flight, with no approval paperwork required.

The GRAVL Core 30 is the flagship of this collection: India's first semi-solid state power bank, delivering 30W PD fast charging through built-in Type-C and Lightning cables, with a live LCD display so you always know exactly how much charge you have left. It works across iOS, Android, and earbuds alike, so one device covers everything in your bag instead of three separate cables. Whether you're commuting, travelling, or simply keeping your phone alive through a long day, this collection is designed for people who want fast charging without compromising on safety, and who would rather trust the engineering than take a manufacturer's word for it.

GRAVL. Which stands for peace of mind, safety, reliability, and transparency.

Have a question ? We are here to help.

Check out the most common questions our customers asked. Still have questions ? Contact our customer support.

It depends on the output, not the mAh figure. A power bank only charges a laptop properly if its wattage meets or exceeds what the laptop draws while in use. GRAVL's laptop power banks are built around this: the Axis 67 outputs 67W, the Forge 130 outputs 130W total (65W + 65W simultaneously), and the Engine 240 outputs 240W total (140W + 100W simultaneously).

The Axis 67 is sized for a MacBook Air M2 or M3 and similar ultrabooks. The Forge 130 is built for a MacBook Pro 14-inch, especially when a phone needs to charge at the same time. The Engine 240 is built for a MacBook Pro 16-inch M4 Max running at full load, and also covers high-performance Windows laptops like the Dell XPS, ASUS ROG, and HP Spectre.

Yes. All three the Axis 67, Forge 130, and Engine 240 stay within IATA's 100Wh carry-on limit, so none require prior airline approval. The Engine 240 sits at 97.2Wh, just 2.8Wh under that ceiling, making it the
highest-capacity airline-compliant option in the collection. Full rules at Airline Rules for Laptop Power Banks.

Yes, iPhone 12 or newer. The GRAVL Qi Surface power bank delivers 25W wireless charging on iPhone 16 and 17. Faster than Apple's own MagSafe on older models. If wireless has ever frustrated you, this is the version that doesn't.

Every laptop power bank in this collection carries a 4-year warranty: 1 year unconditional from the date of purchase, plus an additional 3 years on the
battery once the product is registered. Both parts of the warranty apply regardless of which model
is purchased.