BigBlue · United States
Exact revision: B401D back-contact revision without ammeter (1x USB-A plus 2x USB-C). Distinct from the B401E ammeter sibling and from older 3x USB-A B401D hardware
BigBlue’s 28W folding charger feeds phones, tablets and power banks straight from regulated 5V USB ports in direct sun. It stores no energy and exposes no DC station output, so it is a device charger rather than a power-station panel.
Availability checked 2026-10-12. Stock can change. We may earn a commission.
BatteryRank review
Choose the SolarPowa 28 for charging a phone or power bank while you stop in direct sun. It has no battery, so you cannot use it after dark without stored power. For a power station, choose a panel with the DC output your station requires.
Availability checked 2026-10-12. Stock can change. We may earn a commission.
Specifications below are manufacturer claims. Each reading opens its source attribution and check date.
Review notes
The panel offers one USB-A and two USB-C ports with 5V/3A maximum per port and 5V/4.8A shared. A phone can use one port and a power bank another, but they share the available output. Shade can slow or interrupt charging. After moving the panel back into sunlight, check that the device has resumed charging.
What changes the decision
The current model has USB outputs and no station solar connector. A USB-C socket does not mean laptop-class USB Power Delivery. BigBlue specifies 5V output, so do not buy this expecting higher-voltage charging or station solar compatibility.
The spec table lists 0.68 kg / 1.5 lbs, while the page body states 680g in one block and 670g in another. The 2022 manual lists 610g for the older three-port revision. We use the spec-table figure and keep the conflict visible.
BigBlue describes moisture resistance but publishes no IP code for this revision. Keep the USB connections and your devices dry. Check the selected listing for included cables because older B401D manuals describe different hardware.
Before connecting
Unfold the panel and aim the cells at direct sunlight. Keep every section clear of shade and reposition it as the sun moves. The headline rating does not tell you how much power your device will receive in those conditions.
BigBlue rates each port at up to 5V/3A and all ports together at 5V/4.8A, or 24W. When sunlight is weak, charge the device you need most first. A spare port does not create extra panel power.
Connect a power bank whose input accepts the panel’s USB output. You can then use whatever energy it stores to charge a phone after dark. Keep the bank shaded and check that charging resumes after clouds pass.
This charger outputs regulated 5V USB only. It has no solar-panel DC output, so the station-side solar panel pairing guide does not apply to it. Charge a power bank from it in the sun, then run devices from the bank.
Manufacturer documentation
These figures are manufacturer claims. Open a reading for its source and check date. USB output figures are regulated 5V ratings, not raw panel Voc or Vmp.
Exact model questions
It has no DC solar output. BigBlue specifies regulated 5V USB, so we do not claim compatibility with a station’s solar input. Use it for supported USB devices or a power bank. To charge a station, choose a DC panel that matches its input requirements.
No. The ammeter sibling is a separate listing with two ports, 20W working power and a 5V/4A shared ceiling. This dossier covers only the no-ammeter B401D with one USB-A and two USB-C ports.
The 28W figure is BigBlue’s panel rating. The 24W figure is the published shared maximum across its USB outputs. Neither guarantees charging at that rate. Sunlight, shade and the connected device’s input limit affect what you receive.
BigBlue publishes no IP code for this revision. Bring it under cover when rain starts, and keep the USB ports and connected electronics dry.
Evidence record
Each manufacturer source below carries its check date.
https://bigblue-tech.com/products/28w-sunpower-solar-charger
Checked 2026-10-12
https://bigblue-tech.com/products/28w-sunpower-solar-charger-with-ammeter
Checked 2026-10-12
https://dwn.alza.cz/manual/109454
Checked 2026-10-12
https://bigblue-tech.com/cdn/shop/files/SolarPowa_28_without_ammeter_BC-2_480x480.png?v=1742953319
Checked 2026-10-12
Reviewed by the BatteryRank Engineering Team for BatteryRank. Review date: 2026-10-12.
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