Elecom has released the "DE-C91L-10000 series," a mobile battery that packs a 10,000mAh capacity into a body roughly the size of a credit card, with shipments starting in mid-June 2026[1]. It supports USB Power Delivery at up to 30W while weighing only about 185g, and it features an LED panel that shows the remaining charge in 1 percent increments. Pitched as a high-capacity battery you can carry every day, it has also been covered by outlets such as ASCII[2].
10,000mAh in a Card-Sized Body
The standout trait is the balance between capacity and size. The body is roughly as large as a credit card and weighs about 185g, slipping easily into a bag or pouch pocket while still holding a 10,000mAh capacity[1].
It is not just about capacity, though; charging speed comes along with it. With USB Power Delivery 30W support, Elecom says an iPhone 17, for example, can be charged to about 63 percent in 30 minutes[1]. Beyond smartphones, it can charge a wide range of devices, including wireless earbuds, tablets such as the iPad, and compatible laptops like the MacBook Air. It also supports charging the Nintendo Switch 2, Nintendo Switch, and Nintendo Switch Lite (depending on the operating mode, playing while charging may not be possible)[1].
The unit has two ports, USB Type-C and USB-A, so it can charge two devices at once. Used individually, the Type-C port outputs up to 30W and the USB-A port up to 22.5W, but when both ports are used simultaneously the combined output is capped at 15W[1]. A short USB Type-C cable (about 10cm) in a matching body color is also included, a small touch that helps in daily use.
An LED Panel That Shows the Charge in 1 Percent Steps
A handy feature for an everyday carry item is the built-in LED panel. Because it shows the remaining charge in 1 percent increments, you can tell at a glance how much power is left before you head out[1].
Conventional power banks often rely on a four-step lamp indicator, which makes it hard to know exactly how much capacity remains. A numeric display in 1 percent steps makes it easier to decide whether to top up before leaving, helping you avoid running out of power when it matters most.
Convenient Charging Features Such as Pass-Through
The charging features are well rounded. The battery supports "charge-together" operation, which lets you charge both your smartphone and the battery itself while the charging cable is plugged in. In this mode the smartphone is charged first, and power flows to the battery once the phone is done[1].
It also supports pass-through charging, which sends power directly from the charger to the connected device without routing through the battery, helping reduce battery wear. On the USB-A port, you can use "auto charging," which automatically detects the connected device and charges it at the optimal output, as well as a low-current mode for small devices like earbuds. Support for the PPS (Programmable Power Supply) standard, which adjusts voltage automatically in 0.02V steps, also helps charge compatible devices efficiently[1].
As for runtime, a full charge is enough to recharge a 1,800mAh smartphone about 3.3 times and a 3,000mAh smartphone about 1.9 times. The unit itself fully charges in roughly 2 hours and 20 minutes, with an expected cycle life of about 500 charges[1].
Safety Design and Carry-On Compatibility
Because this is a product meant to be carried around, safety has been considered as well. The built-in lithium-ion battery is designed to comply with the JIS C 62133-2:2020 and JIS C 8715-2:2024 standards and clears the technical requirements of Japan's Electrical Appliance and Material Safety Act (PSE). It also includes Thermal Protection, which monitors and controls the unit's temperature during operation[1].
In addition, because it is a lithium-ion battery with a rated capacity of 160Wh or less, it can be brought aboard aircraft (exceptions may apply depending on the airline's rules). That makes it easy to take along on business trips or travel[1].
Price and Color Options
The price is 5,980 yen at the typical store price (5,436 yen excluding tax)[1][3]. Two options are available: a subdued black (model number DE-C91L-10000BK) and a white "Shirochan" model featuring Elecom's character Shirochan (model number DE-C91L-10000WF). The product is also certified under Elecom's environmentally conscious "THINK ECOLOGY" program[1].
Summary
The DE-C91L-10000 series is a power bank that combines card-sized, roughly 185g portability with a 10,000mAh capacity and USB Power Delivery 30W fast charging. With an LED panel that shows the charge in 1 percent steps, practical features like pass-through and auto charging, and carry-on compatibility, it feels built around the idea of being carried every day. Priced at 5,980 yen (5,436 yen excluding tax) and offered in two colors, standard black and the Shirochan model, it looks like a strong option for anyone after a daily-use battery.
Source: https://prtimes.jp/main/html/rd/p/000001438.000026881.html
