Jump starter for a truck: what CCA do you need at 24V?

A truck does not start like a regular car. Most commercial vehicles above a certain weight run on 24V instead of 12V, with two batteries in series. That has direct consequences for which jump starter you need, and it is exactly the point where a wrongly chosen jump starter leaves you stuck by the roadside.

Why do trucks have a 24V system?

Heavy diesel engines need a lot of power to start, especially in the cold. By connecting two 12V batteries in series, the truck doubles the voltage to 24V. That delivers enough power for the large starter motor and keeps the required current, and therefore the cable thickness, manageable. Most vans up to 3.5 tonnes stay on 12V. You mainly encounter 24V with heavier commercial vehicles and tractor units.

Does a regular 12V jump starter work on a truck?

No. A 12V jump starter simply does not deliver enough voltage to get a 24V system going. You are still stuck. For a truck you need a jump starter that explicitly supports 24V. So when buying, always check the voltage stated on the device itself, not just the CCA value: a high CCA at 12V does not solve a 24V problem.

Which jump starter does work at 24V?

In our line, that is the Boost Dual 12400. This model switches between 12V and 24V, with a starting power of 2880 CCA. That makes it big enough for most truck and tractor unit diesels. For a regular passenger car, this model is overkill. Choose a lighter model based on the CCA on the battery label instead.

How much CCA does a truck battery have?

That varies by brand and model, so always check the label on the batteries themselves, just as with a passenger car. How to read those figures is explained in reading CCA and EN on your battery label. Trucks often have two batteries side by side. Both need to be in order, since the jump starter helps get the whole 24V system going, not a single separate battery.

Is a 24V jump starter also suitable for lighter commercial vehicles?

Yes, but then it is often bigger and heavier than necessary. A van up to 3.5 tonnes usually just runs on 12V, like a passenger car. For that, choose a lighter model from the range based on the CCA on the battery label. Save the Boost Dual 12400 for situations where you are certain you are dealing with 24V: a truck, tractor unit, or heavy agricultural or construction vehicle. If you are unsure about your commercial vehicle's system, check the registration certificate or the maintenance manual before buying a jump starter, since that prevents a purchase that ultimately does not fit.

Watch out for peak current claims

With cheap jump starters for heavy diesel engines, you often see a high peak current figure in amps on the packaging, without the CCA value listed alongside it. Peak current and CCA are not the same: peak current is a brief peak value, CCA is the actual starting power at a cold start. If in doubt, always ask for the CCA, not the peak current figure, especially with a large diesel engine where the gap between an inflated number and the actual starting power is greatest. More explanation is available in peak current or CCA: what does that big number really say?.