- Most sloops, motorboats and sailboats with an outboard motor run on a regular 12V battery, just like a car. A 12V jump starter works fine for that.
- How much CCA you need depends on the engine type: a small outboard motor needs less than a diesel inboard.
- A boat battery label often shows MCA instead of CCA. That's a different measurement, so don't simply compare one number with the other.
- Does your boat have a 24V system, like some larger motor yachts? Then you need the Boost Dual 12400, not a regular 12V jump starter.
Trouble on the water is more inconvenient than on the road. You can't just pull onto the shoulder and call roadside assistance, and a flat battery at the jetty simply means you're not going anywhere. A jump starter on board prevents that, provided you choose the right one. Picking the wrong model is also a waste of money: too light and it won't start your engine, too heavy and you're carrying unnecessary weight on board. Below you'll read which CCA value suits your boat and what to watch for.
What CCA does your boat's battery have?
A boat battery works on the same principle as a car battery: the bigger the engine, the more starting power is needed. So just like with a car, check the label on the battery itself first. For a small outboard motor up to about 4 litres petrol-equivalent, the battery is comparable to that of a compact car. For a larger outboard motor or a diesel inboard, the required CCA is considerably higher, comparable to a camper van or a light delivery van.
MCA on your boat battery is not the same as CCA
Many marine batteries show MCA (Marine Cranking Amps) instead of CCA. That's not just another name for the same number: MCA is measured at a higher temperature than CCA, so the MCA figure on the same battery quickly comes out higher than the CCA value. So when comparing a boat battery with a jump starter's CCA requirement, go by the CCA value if it's listed, not the higher MCA figure. If in doubt, choose a model with some margin rather than one that sits right on the edge.
| Situation | Engine type | Recommended model |
|---|---|---|
| Small sloop or tender | Outboard motor, small, petrol | Boost Mini 3750 (620 CCA) |
| Motorboat or sailboat with auxiliary engine | Larger outboard motor or diesel inboard up to 6.5 L | Boost Pro 8250 (960 CCA) |
| Larger motor yacht with 24V system | Diesel, 24V | Boost Dual 12400 (12/24V, 2880 CCA) |
Why moisture and salty air make a jump starter extra vulnerable
Electronics and water don't mix well, and on the water moisture is everywhere. So store your jump starter in the supplied pouch and keep it dry, even if you leave it loose in a locker or cockpit bag. Make sure your hands and the battery terminals are dry before you connect the clamps. If you come back from a day on the water with a wet boat, let the jump starter dry before you put it away again.
How do you connect a jump starter to a boat battery?
The same way as with a car. Connect the red clamp to the positive terminal and the black clamp to the negative terminal, directly on the battery. On most boats the battery terminals are easy to reach, so a remote ground point isn't needed. As soon as the screen shows "12V Ready", you can start the engine.
Extra handy on board: power bank and flashlight
A jump starter does more than just starting on board. The Boost Mini 3750 and the Boost Pro 8250 both have a built-in flashlight, handy if you're still mooring in the evening or need to check something in the engine room. Both models also work as a power bank via the USB output, so you can charge your phone or navigation device on the go without drawing on the ship's battery for it. Especially on the water, where a wall socket isn't around the corner, that's a welcome bonus.
- 960 CCA, suitable for larger outboard motors and diesel inboards up to 6.5 L
- 16,000 mAh, good for multiple starts per charge
- Smart clamps with protection against reverse polarity, short circuits and sparks
Frequently asked questions
Does a regular jump starter work on a boat?
Yes, for most sloops, motorboats and sailboats with a 12V battery, a regular 12V jump starter works, as long as the CCA value suits the engine.
What's the difference between CCA and MCA on a boat battery?
MCA is measured at a higher temperature than CCA, so the MCA figure on the same battery comes out higher. So compare the CCA value with the jump starter's CCA requirement, not the MCA figure.
Which jump starter do I need for a diesel inboard?
For a diesel inboard up to 6.5 litres, the Boost Pro 8250 with 960 CCA is suitable. If your boat has a 24V system, you need the Boost Dual 12400.
Does my boat have a 12V or 24V system?
Most sloops, motorboats and sailboats have 12V. Larger motor yachts sometimes have 24V. Check the manual or ask the boatyard if you're not sure.
What's the best way to store a jump starter on board?
Dry and in the supplied pouch, out of direct sunlight. Make sure your hands and the battery terminals are dry before you connect the clamps, and let the jump starter dry after a wet day on the water.
