CTEK RB 4000 Portable Jump Starter - 4000A Battery Peak Current review
Drivers with larger engines or frequent breakdown-cover-style use who want CTEK's build quality and 2-year warranty, not just a cheap booster.
By Tom Calder · Price last checked 20 Sep 2026, 12:29 BST · price-tracked
The RB 4000's headline 4000A is a marketing peak figure — the real-world number is the 2060A maximum cranking current, still a credible step up from CTEK's own RB 3000. It's expensive for a lithium jump pack, so it earns its price on engineering and warranty rather than the badge number; like any lithium pack, store it indoors rather than in a hot car boot or a freezing shed.
as of 20 Sep 2026, 12:29 BST · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.ⓘ As an Amazon Associate, PreparedBritain earns from qualifying purchases. We may earn a commission when you buy, or a fee when you request a quote, through our links — it never affects what we recommend. Amazon prices come from Amazon's own product data and show the date and time they were retrieved. Prices at other retailers are checked by us, less often. Prices and stock can change at any time, so always check the retailer's price before you buy.
- Genuine reverse-polarity and spark-proof protection from an established 12V specialist (CTEK), not just a marketing claim
- Doubles as a real power bank (USB-A QC3.0 + USB-C PD30W) and 3-mode LED torch
- 2-year warranty and UK support/spares via CTEK's own store
- It costs 3-4x a NOCO or GOOLOO booster with broadly similar real cranking output
- CTEK doesn't publish a litre-based engine limit, so buyers must judge fit from the 2060A cranking figure rather than a simple 'fits my car' claim
Who shouldn't buy this
Don't buy this if you only want an occasional emergency booster for a small petrol car — a NOCO GB40 or GB70 does the same job for a third of the price. The RB 4000 makes sense for larger diesels, frequent use, or if CTEK's warranty and support matter to you.
Key specs
| Peak current | 4000A peak |
| Engine coverage | No litre-specific claim published by CTEK |
| Capacity | 24,000mAh / 88.8Wh lithium-polymer |
| Extras | USB-A + USB-C power bank output |
Our rating is a considered spec-and-evidence verdict: we verify 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 a product isn't for. Commissions never change a rating. Read the full methodology →
Alternatives to consider
as of 20 Sep 2026, 12:29 BST · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.as of 20 Sep 2026, 12:29 BST · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.as of 20 Sep 2026, 12:29 BST · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.Want this cheaper?
Prices for 364 tracked products are refreshed daily — last sweep 20 September 2026. Leave your email and we'll tell you when it drops — nothing else.