BigBlue P25 review
BigBlue SolarPowa P25 Pocket Solar Charger
By Tom Calder
The P25 folds to roughly 12 x 16 cm and weighs 460 g, with one USB-A and one USB-C output. BigBlue rates the panel at 25W but caps combined USB output at 5V/4A, which is 20W, so plan on the lower figure even in full sun. Its own manual says real output falls with weather, season and heat, so on a typical UK day it is a slow top-up for one phone rather than a quick charge.
- Best for
- Carrying a small panel on day trips to top up a phone.
- Skip it if
- You need to charge several devices at speed or want useful output in dull winter light
as of 2 Nov 2026, 16:07 GMT · Details
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Researched, not used. We haven't used this product. This review is built from the maker's specifications, owner reports and our own sizing.
What we like
- Small and light for a two-port panel
- USB-C and USB-A outputs
- Panel rated IP68, and BigBlue offers a 24-month warranty
Worth knowing
- Combined output is capped at 20W against the 25W panel rating
- The IP68 rating does not cover the junction box, which must not be immersed
- No battery, so it only delivers while sunlit
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Our review
BigBlue's SolarPowa P25 is a pocket solar charger: eight panels of back-contact monocrystalline cells that fold to 118 by 163 by 35mm and weigh 460g, with a USB-A and a USB-C port. BigBlue rates it at 25W and says the working output is 20W in total. It is for topping up a phone or a small power bank in daylight, on a walk or in a long outage. It stores nothing, and winter light gives it little.
What BigBlue specifies
BigBlue's product page gives a rated power of 25W and a working power of 20W in total, through a USB-A port at 5V/2.4A and a USB-C port at 5V/2.4A, with the two together capped at 5V/4A. Net weight is 0.46kg. Folded it is 118 by 163 by 35mm; open it is 460 by 326 by 5mm. The cells are monocrystalline back-contact cells that BigBlue puts at up to 25.4% conversion efficiency. The panel is rated IP68, and BigBlue's note says the rating does not extend to the junction box, so the ports and the box they sit in must stay dry.
BigBlue's own FAQ is unusually honest about the headline: the 25W is measured under standard test conditions of 1,000 watts per square metre at 25C, and actual output is lower because of conversion heat, weather, season and location. The USB-C port is a plain 5V output, not USB Power Delivery, so a phone charges at ordinary speed and a laptop will not charge at all.
What a UK day gives you
Met Office long-term averages put December sunshine around 50 hours a month in London and under 30 in Inverness, against roughly 200 and 140 in June. Installers of rooftop systems put winter output at a fifth to a third of summer. On a small hand-held panel that means a phone top-up over a bright winter lunchtime and a useful charge on a clear summer day, with the panel turned to face the sun and moved as it goes round. It is a daylight-only device: the sensible pairing is a power bank that the panel feeds while the sun is out and the phone draws from after dark. Our solar power cut backup guide sets out what small panels can and cannot do.
The limits
No battery, so cloud passing over stops the charge and some phones restart charging only when unplugged and reconnected. The ports share 20W, so two phones at once charge at half speed each. The junction box is not waterproof whatever the panel's rating says. BigBlue publishes no warranty term on the product page, so register it on the maker's site and keep the receipt.
How it compares
On the solar phone chargers page, BigBlue's own SolarPowa 14 is lighter and cheaper with one port, IPX4 and 14W. The BioLite SolarPanel 10+ has a built-in battery, so it charges a phone after dark, at a lower output. The FlexSolar E40 steps up to 40W with USB Power Delivery for a power bank or small laptop, in a bigger fold. The Renogy 30W is the other mid-size choice. The P25 is the best-specified panel that still fits a jacket pocket, and the one to pick for weight; for output, the E40, and for after-dark use, the BioLite.
Our verdict
Buy it if you want a light, two-port panel for walks, festivals or a summer outage, to keep a phone or a small power bank topped up in good light. Skip it if you want useful power in a British winter or need to charge several devices quickly, where a bigger panel feeding a power station, or simply a large charged power bank, is the honest answer.
A researched review, built from the maker's specs, manual and UK listings; facts checked 2 Nov 2026. Sources: BigBlue: SolarPowa P25, specifications and FAQ (read 2 November 2026); Met Office: UK climate averages, sunshine hours by location.
Who shouldn't buy this
You need to charge several devices at speed or want useful output in dull winter light.
Key specs
| Rated power | 25 W |
| Output | USB-A + USB-C, 5V/2.4A each, 5V/4A total |
| Foldable | Yes, 8-fold, 118 x 163 x 35 mm, 460 g |
| Weatherproof | IP68 panel; junction box not covered |
This is a Researched review: we haven't used this product. We check every specification against at least two independent sources, re-check the UK price on a schedule where we can track it automatically, and say plainly who it isn't for. Commissions never change a rating.
If this isn’t the one
Best for The BLUETTI panel most people should pick
Best for The most solar for a big power station that you can still carry
Best for Topping up a Jackery Explorer power station during a longer, daylight-hours off-grid outage.
Questions
How much power does the BigBlue SolarPowa P25 give?
BigBlue rates it at 25W under standard test conditions and says the working output is 20W in total, through two 5V/2.4A ports capped at 5V/4A together. In real UK light expect less, and much less in winter.
Is the BigBlue SolarPowa P25 waterproof?
The panel is rated IP68. BigBlue says the rating does not cover the junction box, so the ports must be kept dry and the panel should not be left out in rain with a cable plugged in.
Does the SolarPowa P25 have a battery?
No. It delivers power only while lit. Pair it with a power bank that charges in daylight and feeds the phone at night.
Can the SolarPowa P25 charge a laptop?
No. Both ports are 5V outputs without USB Power Delivery, so it charges phones, earbuds, GPS units and power banks only.
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