Life

Can You Use A New Fast-Charge Smartphone With An Old Charger?

Your new phone dies and you only have an old charger handy—here's what you should do.

We live in an always-on, always-connected world. And if you’re always connected, sooner or later you’re going to have to recharge. In the wake of the many issues the Samsung Galaxy Note 7 has had recently, it’s a fair question to ask: Can you use one of the zillion old chargers that populate the kitchen junk drawer with a new model smartphone—especially the models with the rapid-charging feature, which enables you to juice up a low-on-power phone in around 15 minutes?

Photo by See-ming Lee 李思明 SML
Photo by See-ming Lee 李思明 SML
Photo by See-ming Lee 李思明 SML

The answer is yes, according to Consumer Reports. They asked  engineers and safety researchers who told them: “There’s no reason to fear a fire, explosion, or even premature death of your smartphone if you mix and match charging devices.”

Photo by avlxyz
Photo by avlxyz
Photo by avlxyz

Rapid phone chargers are designed so that they send power to the device at a higher voltage (9 volts, rather than the 5 volts from standard USB chargers.) While today’s new super-fast chargers are all about speed, “they default to a slower charging setting that’s safe for all smartphones (5 volts at 500mA to 2A) when they sense they’ve been plugged into an unsupported device,” according to Consumer Reports.

Geoff Gordon, a marketing manager at Qualcomm, told Consumer Reports that the chargers are as smart as the phones they plug into. Algorithms help the phone determine just how much power it can accept. So if you plug a fast-charging phone into an older power charger, it’s going to charge at the slow rate—because that’s all the older technology can accept.

Photo by TechStage
Photo by TechStage
Photo by TechStage

Of course, if you’re persnickety about these things (like I am) you only use the charger that comes with the device, period and end of that story! Need a new rapid charger? Amazon’s got ’em. Here’s a video with more on rapid vs. slower chargers:

[h/t: Consumer Reports]

Photo by See-ming Lee 李思明 SML

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