Short answer: a portable Di2 charger is a compact, USB-A unit you can pack for travel and racing, charging your internal SM-BTR2 or BT-DN110 battery from a power bank, laptop or any 5V plug. At just 45g it slips into a race bag or wash kit without a thought.
For riders heading to a training camp or a race away from home, the worry is always the same: pack light, but do not get caught with a flat Di2 the morning of a key session. A portable charger solves it — no bulky cradle, no proprietary mains brick, just a small unit and any USB source.
Why a portable Di2 charger matters for travel
Flying to Mallorca or driving to a sportive, you want a charger that does not eat luggage space and does not depend on finding the right plug abroad. Because the CyclingCharger Di2 internal battery charger (£77.95) uses a standard USB-A cable, you can top up from a UK wall plug, a laptop in the apartment, or a power bank in the team car — handy when you forgot to plug in the night before.
Charging from a power bank or laptop
The unit takes a 5V USB-A input, so any decent power bank or laptop USB port will charge your Di2. A source that supplies at least 1.0A gives the quickest result; a full top-up takes roughly 1.5 to 3 hours. That means you can charge in transit — on the drive to an event, or over breakfast at the hotel — rather than losing an evening to it.
Keeping a backup in the race bag
Endurance and triathlon riders often keep a second charger permanently in the race bag, so a flat battery is never the reason a session or a race day is lost. At 45g it adds nothing to your kit, and a backup means you are covered even if your main charger stays plugged in at home.
What to pack for a trip
- The compact USB-A charger (45g) and a short USB cable.
- A power bank you already trust, or your laptop as a backup source.
- A UK-to-local plug adapter if you are travelling abroad.
Order in good time so it arrives before you leave — the CyclingCharger unit ships with free tracked UK delivery. New to Di2 charging? Start with how to charge Shimano Di2 battery systems, or compare options in our Shimano Di2 charger buyer's guide.
The CyclingCharger Di2 charger
The CyclingCharger Di2 internal battery charger is made for the road. It replaces the SM-BCR2 charging function for internal SM-BTR2 and BT-DN110 batteries, connects at your SM-EW90-A/B or EW-RS910 junction box, and charges over a standard USB-A cable (5.0V in, 8.4V DC 1.0A out) in about 1.5 to 3 hours. At just 45g, with UKCA, CE and RoHS marking, it costs £77.95 inc VAT (£64.96 ex VAT) and comes with a 12-month warranty, free tracked UK delivery and 30-day returns — rated 4.8 out of 5 from 256 reviews. For 11-speed internal systems only.
Packing for a training camp or race?
SM-BTR2 and BT-DN110 compatible · UKCA certified · Free UK delivery · £77.95
Frequently asked questions
Can I charge a Di2 battery from a USB power bank?
Yes. The CyclingCharger unit takes a 5V USB-A input, so a power bank charges your internal SM-BTR2 or BT-DN110 battery just like a wall plug. Use one that supplies at least 1.0A for the quickest charge.
Is there a compact Di2 charger for travel?
Yes. The CyclingCharger unit weighs just 45g and uses a standard USB-A cable, so it packs into a race bag or wash kit and charges from any 5V source without a bulky mains brick.
Should I pack a spare Di2 charger for a race?
Many endurance and triathlon riders keep a backup charger in the race bag so a flat battery never costs them a session. At 45g and £77.95 with free UK delivery, a spare is cheap insurance.
Does the portable Di2 charger work with a UK plug?
Yes. The USB-A cable plugs into any 5V UK wall adapter, and abroad you can use a simple plug adapter, a laptop, or a power bank as the source.