As regular readers will know, I have an ageing fleet of cars. When I am organised, I usually have each car connected to a CTEK trickle charger. However, there are times when I want to head out for a drive, only to find a car with a flat battery.

If you’ve ever messed around with jump cables, you will know what a performance that can be. Line up another car, not too close, connect the two cars and hope for the best. Occasionally sparks fly and I’ve never been keen.

The good folk at CTEK do have a solution in the form of the RB 4000 unit. This is a premium 12V portable jump starter which I was pleased to find out comes with smart safety features. It isn’t cheap, but its performance, build quality and versatility go some way to justify the price.

The RB 4000 is basically a lithium-ion pack which will deliver a 4,000A peak current and around 1,300A starting current. In layman’s terms, this means the unit should be good for around 45 jump starts on a single charge. It should cope with the very largest batteries fitted to petrol and diesel engine cars and vans.

The RB 4000 features spark-proof technology, reverse polarity protection and intelligent checks that prevent operation if the connections are wrong or the battery is unsafe. Perfect for people like me with just the basic mechanical knowledge. An LED display and clear indicator status guide you through the process. It is also dust and water resistant, so you should be fine using it on a rainy day.

The RB 4000 does have other uses too. It can act as a power bank with the capability to fast charge modern smartphones and tablets. Perfect for camping trips or if your home experiences a power cut.
There’s a built-in LED flashlight with multiple modes, useful if you break down in a dangerous location.

The unit can be recharged quite quickly via a USB-C. I’m told around three and a half hours if it is completely flat and CTEK claim around 8 months of standby time, not tested yet.

Like all CTEK products, the RB 4000 feels well made and sturdy enough to stand the test of time. It is compact enough to keep in your car all the time, which will give reassurance especially during the winter when car batteries are under more pressure.

So, how easy is it to use? Our old Toyota RAV-4 had not moved in a while and attempting to start it was met with nothing more than a click. No sign of life at all. The unit was quickly connected and as the battery was clearly very flat, I Ieft the boost pack connected for a few minutes before attempting to start the car. It burst into life straight away – job done and oh so simple to use.

Expect to pay around £370 for the CTEK RB 4000, but considering its power, versatility and build quality, it may be worth the outlay, especially if you have multiple old cars like me.