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Rich Warren | Power On: Charging Electronic Devices | Science and Technology

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Please charge first! Most gears require a battery charge.

This reader’s letter reveals the nuances of charging.

“My question is about newer, better, and smaller USB-C options, as referenced in the June 12th column.

I recently purchased a new iPhone 13, which includes a USB-C (to Apple Lightning) cable and no adapter.

Apple manufactures a 20W USB-C fast charging power adapter. Is this okay with daily charging, or is it safer to use a low watt adapter? What do you recommend? “

Maximum charge recommended by the manufacturer. In addition, it is safe to use a charger with a higher wattage than the product requires.

For example, you might charge a Pixel smartphone, which Google proposes a 30-watt charger, with a 65-watt Dell laptop charger. Conversely, laptops are undamaged, but I don’t like charging with a 30 watt phone charger.

Most of today’s well-designed electronic devices accept a wide range of charging currents without damage. When the battery is fully (or almost fully) charged, almost everything will automatically stop charging. If you want to extend the battery life, manually remove the charger when the battery reaches 95%. Avoid continuous charging whenever possible. On the other hand, do not discharge below 20%.

Mobile phones, tablets, laptops, and other electronic devices contain “fail-safe” circuits, but they may not be able to protect them from poorly designed chargers and charging cables. Most products do not come with a charger, but they do include a manufacturer-approved cable. If you forget the overpriced chargers sold by the manufacturer of your product, there is a shocking array of aftermarket chargers. Sadly, few laboratories or institutions test these for exactly the 5 volt USB standard. Most chargers are sourced from other parts of China or Asia (excluding Japan) that are not UL or equivalent Canadian CSA safety certified.

Be careful if the price of the power / adapter appears to be unusually low. Also, while house brands such as Amazon Basics are often a good buy, they are rarely guaranteed to be safe.

Most power adapters incorporate the largest and oldest USB-A outlet of the many USB ports. Many of the new ones come with the latest small USB-C (3.1) ports that are becoming the global standard. The European Union claims that all new electronic devices that require USB charging come with this port. The new product is putting pressure on Apple to replace the Lightning port with USB-C.

Check the jack on your device to see if you have several USB sizes you need. For example, you can’t charge your Kindle with the same plug that charges your new Android phone.

You can choose a power adapter with up to four outlets, depending on the number of devices you want to power / charge at one time.

Keep in mind that if the manufacturer rates the adapter as 40 watts and connects and charges four devices at the same time, each will only receive 10 watts, which can slow down charging.

Cables between the power adapter and the device play an important role in further confusing the problem. Some inexpensive cables are not routed properly or cannot carry the required wattage between the power adapter and the device. It can ruin adapters and devices and, in rare cases, ignite.

At this point, we’re waiting for guidance on which brands to buy, but as mentioned earlier, many brands are listed with ambiguous names.

Some of the so-called well-known brands hanging on Target and Walmart are made on the same assembly line as unknown brands.

Anker is one of the most acclaimed Chinese brands.

Best known for phone cases, Spigen has branched into power supplies using the latest and most efficient gallium nitride technology. So far, these work well for me.

Two trusted review sources, CNET and the New York Times’ Wirecutter, recommend RAVPower, Anker, and Spigen.

Rich Warren, who lives in the Champaign region, has been a longtime reviewer of consumer electronics. Send him an email at