Specifications checked 31 October 2026 · MLC editorial team · UK trade workshop perspective
A generator for a workshop or site needs more than a headline wattage: you need the continuous output, the sockets that match your tools and a safe place to run it. This guide compares three generators sold on Amazon UK, from about £520 to £1,450, using manufacturer and UK retailer pages checked on 31 October 2026. Where makers or sellers disagree on a figure, we say so.
How we picked these
- Rated (continuous) output, not the peak figure in the product title
- Sockets: 13A, 16A or 32A, and whether there is a 110V outlet
- Inverter or not: an inverter gives cleaner power for electronics
- Weight and whether one person can move it
- Models still sold, with a working Amazon UK listing
We have not tested these products. Every specification comes from a manufacturer or UK retailer page, and Amazon prices were read on 31 October 2026 and change daily. Links are affiliate links: MLC earns a commission on qualifying purchases.
Reviewed picks
As an Amazon Associate, My Local Components earns from qualifying purchases.
Inverter petrol
Hyundai HY6250SEi 5.5kW Inverter Generator
Hyundai rates it at 5,000W continuous and 5,500W peak, with a pure sine wave inverter, 223cc 4-stroke engine and electric start. It has a 32A industrial socket and a 13A socket, an 11 L tank, and Hyundai quotes 21.7 hours at 10% load and 6 hours at 50% load. It weighs 39 kg and has a 3-year home and 1-year commercial warranty. Amazon quotes noise at 69 dBA at 7 m, which we could not confirm on the maker page. Hyundai's page and its FAQ disagree on whether it has a recoil backup start.
Amazon UK price seen 31 October 2026: £944.99 · Hyundai HY6250SEi on Amazon UK (ad)
Hyundai HY3900Si 3.3kW Inverter Generator
Rated at 3,000W continuous and 3,300W peak, with pure sine wave, a 144cc engine and recoil start. It has a 4 L tank and Hyundai quotes 6.3 hours at 10% load and 3.6 hours at 50% load. It weighs 21.15 kg and has a 3-year home and 1-year commercial warranty. Its only mains outlet is a 16A industrial socket, so a standard 13A plug needs an adaptor lead. Hyundai's own sources give noise as 63 dBA in one place and 67.6 dBA at 7 m in another. Amazon's table lists the frequency as 60 Hz, but Hyundai states 50 Hz.
Amazon UK price seen 31 October 2026: £523.99 · Hyundai HY3900Si on Amazon UK (ad)
Site diesel
Sealey DG5000 Diesel Generator
Sealey rates it at 4.6 kW continuous and 4.8 kW maximum, not the 5,000W in the product title. It is not an inverter, so keep sensitive electronics off it. It has 230V 32A, 110V 32A and 110V 16A outlets and no 13A socket, electric start, 97 dB(A) noise, an 18 L tank and a 7-hour run time on Sealey's current page. It weighs about 150 kg, so it is not hand-portable. Warranty is 1 year.
Amazon UK price seen 31 October 2026: £1,448.75 · Sealey DG5000 on Amazon UK (ad)
Recommendations at a glance
| Pick | Amazon UK price | Link |
|---|
| Hyundai HY6250SEi 5.5kW Inverter Generator | £944.99 | Amazon |
| Hyundai HY3900Si 3.3kW Inverter Generator | £523.99 | Amazon |
| Sealey DG5000 Diesel Generator | £1,448.75 | Amazon |
Related reference on MLC
Frequently asked questions
What do running watts and peak watts mean?
Running (rated) watts are what the generator can supply continuously. The higher peak figure is only for short bursts. Hyundai's HY2350Si, for example, is 1,800W continuous and 2,000W maximum, so size for the continuous figure.
What starting power do motors need?
Sealey says induction-motor appliances such as air compressors can need about three times their rated wattage to start, and advises adding 20% to your total wattage. Sealey's guide does not cover welders, so use the welder's own input rating.
Can I run a generator indoors?
No. The HSE says never to use petrol-powered equipment such as generators indoors or in enclosed spaces unless the ventilation has been fully assessed, because even a few minutes can create fatal carbon monoxide levels.
Can I plug a generator into my building's sockets?
Sealey's DG5000 manual warns against connecting the generator to a building's mains sockets. Feeding house wiring needs a proper changeover arrangement fitted by a qualified electrician.
What does the HSE say about site tools and voltage?
The HSE advises cordless tools or 110V centre-tapped-to-earth supplies on construction sites, because domestic-grade 230V tools and cables are not suited to site conditions. The Sealey DG5000 has 110V outlets. The two Hyundai models listed here are 230V.
How we checked this
- We compared manufacturer pages and UK retailer listings and used a figure only where a named page gave it.
- Where sources disagreed, we left the figure out or said so.
- We did not list the Stephill GE3300 or 5000HMSLR because Amazon prices were well above other retailers and the 5000HMSLR is shown as no longer available at ITS.
- We did not list the Excel Power 3200W (no maker source), the Honda EU10i (only 900W and far dearer on Amazon than at Honda) or the Hyundai HY2350Si (sold out at the maker).
- Amazon prices differ from the prices at Hyundai and other UK retailers, so compare before buying.
Sources
Data as at 31 October 2026.