Two car chargers sit side by side. One says 18W. The other says 30W. The second costs a few hundred rupees more, so most shoppers assume it charges faster.
Sometimes it does. Often, though, it makes no difference whatsoever. The reason lies in a detail almost nobody checks: how much power your specific phone can actually accept.
Output Is the Number That Matters Most
Output tells you the maximum power a charger can deliver. Manufacturers print it as watts, so you see 18W, 22.5W or 30W on the packaging.
However, output describes a ceiling, not a promise. Your phone decides how much of that ceiling it uses. Therefore, buying more watts than your device supports simply wastes money.
This is where most people go wrong. They compare wattage numbers alone. Meanwhile, the best car chargers get chosen by matching output to the device sitting in your hand, not by picking the biggest number on the shelf.
Reading the Output Label Correctly
Charger boxes list several figures. Learn to read three of them and you will never be confused again.
Once you understand this section, product pages stop looking like technical jargon. You will spot an honest listing immediately, and you will also spot a vague one.
Watts, Volts and Amps
Watts equal volts multiplied by amps. A charger delivering 9V at 2A produces 18W. That is the entire formula.
Chargers usually list multiple combinations, such as 5V/3A, 9V/2A and 12V/1.5A. Your phone picks whichever combination suits it. So a longer list of options generally means broader compatibility.
Total Output Versus Per-Port Output
Here is the trap. A charger advertised as 30W may deliver 30W through one port alone. Plug in a second device and that 30W splits between both.
Consequently, always look for per-port figures. Honest brands publish them. Vague listings that only shout a total number usually hide a weak second port.
Your Phone Sets the Real Limit
A charger cannot force power into a device. The phone negotiates first, then draws what it can handle. This handshake happens every single time you plug in.
So the practical question changes. Instead of asking how much a charger delivers, ask how much your phone accepts. That number is your target.
If You Use an iPhone
Apple does not publish official wired charging speeds. However, independent testing shows recent Pro models peak at roughly 27W during the early part of a charge.
A 20W charger therefore gets you most of the way there. A 30W charger lets the phone draw its full speed. The real-world gap between them measures only a few minutes over half an hour.
If You Use an Android Phone
Android varies far more. The base Galaxy S25 charges at up to 25W, while the S25+ and S25 Ultra support 45W. Many mid-range Samsung, Infinix, Tecno and Xiaomi phones cap around 18W to 25W.
One caveat matters for Samsung flagships. Reaching 45W requires PPS support specifically, not just high wattage. Without PPS, those phones typically settle around 15W to 22W regardless of the charger rating.
Why Protocols Matter as Much as Wattage
Wattage answers "how much". Protocols answer "how". A charger without the right protocol cannot deliver its rated speed to your device, no matter what the box claims.
Power Delivery covers iPhones and most modern USB-C phones. Quick Charge covers a wide range of Android devices. VOOC and AFC handle OPPO and Samsung's older fast-charge systems respectively.
Multi-protocol chargers solve this neatly, which is why the best car chargers rarely support just one standard. The Interlink RIDE 22.5W, for example, supports PD, Quick Charge, VOOC and AFC together, so it adapts automatically to whichever phone you plug in. Our guide on Type-C vs USB chargers explains the connector side in more detail.
The Cable Completes the Circuit
Output means nothing without a cable rated to carry it. This single oversight ruins more charging setups than any other factor.
A thin or damaged cable creates resistance. Resistance limits current and generates heat. As a result, a 30W charger paired with a poor cable might deliver barely half its rated output.
Match the cable to the job. Use a proper USB-C to USB-C or USB-C to Lightning charging cable rated for your target wattage. If speeds still disappoint, our post on phone charging slowly covers the remaining culprits.
Matching Interlink Output to Your Device
Interlink offers three output tiers, and each one fits a clear use case. Choose by device rather than by price alone.
Pick the ELITE PLUS 18W (Rs. 800) for basic phones and short commutes where a steady top-up is all you need. Pick the RIDE 22.5W (Rs. 900) if your household mixes brands, since its multi-protocol support handles iPhone, Samsung, OPPO, Vivo and Xiaomi from a single unit. Pick the REVIVE 30W PD (Rs. 1,100) if you carry an iPhone or a USB-C flagship and want full Power Delivery speed, plus a second port for a passenger.
One honest note for Galaxy Ultra owners. A 30W PD car charger will charge your phone quickly, but 45W speeds require PPS support, so expect solid rather than maximum performance. Browse all three on the car charger collection, where every unit ships with a 6-month warranty and free delivery nationwide.
Frequently Asked Questions
Will a higher output charger damage my phone?
No. Your phone negotiates and draws only what it supports. Extra output sits unused, which is why the best car chargers are safe to buy slightly above your current requirement.
Is 18W enough for a modern smartphone?
For most mid-range phones, yes. An 18W charger delivers a solid top-up during a typical commute. Flagship owners who want maximum speed should step up to 30W.
Why does my 30W charger seem slower with two devices?
Because total output splits across ports. Check the per-port rating rather than the headline figure before assuming a fault.
Does higher wattage mean faster charging for every phone?
No. Speed stops increasing once you reach your phone's own limit. Beyond that point, extra wattage only helps when charging a second device.
Final Thoughts
Choosing output correctly takes three steps. Find your phone's maximum charging speed. Check the charger's per-port output and supported protocols. Then pair both with a cable rated for the job.
Get those three right and you buy exactly what you need. The best car chargers are simply the ones matched properly to your device, so there are no wasted rupees on unusable wattage and no frustration from a unit that quietly underperforms.