Marine batteries are available in various sizes to suit different needs. Here are the common marine battery sizes:

Group 24:
Suitable for small to medium-sized boats and marine vehicles.
Capacity: Typically ranges between 70-85 amp-hours.

Group 27:
Suitable for a wide range of marine applications.
Capacity: Offers a balance of power and space, with typical capacities between 85-110 amp-hours.

Group 31:
Ideal for larger boats and vessels with higher power requirements.
Capacity: Offers higher amp-hour ratings, generally ranging from 95-125 amp-hours.

Group 8D:
Suited for large marine vessels and can accommodate demanding power needs.
Capacity: Provides substantial power reserves, often offering amp-hour ratings upwards of 225.

Understanding the available marine battery sizes allows you to select the most suitable option based on your specific requirements for power capacity and physical dimensions.

This is useful when you know the power rating of the device. Wattage divided by voltage gives the amp-hour rating of marine electronics.
For example, assuming you have a 20W light, a 10W navigation system, a 40W autopilot system, a 10W radar, a 40W navigation light, and a 30W water generator, the total wattage is:

W=20+10+40+10+40+30=150W

If you plan on using it for six hours on a single charge,

Wh= 150W x 6h = 900Wh

Now divide this by the voltage to get the Ah rating. For 12V marine systems,

Ah = 900 ÷ 12 = 75 Ah

No, Enjoybot only offer deep cycle battery, our battery is not designed for starting engines, it can not be used as a cranking battery due to BMS setting. When the boat's engine has started, the boat's engine needs continuous and reliable power for trolling motors, which is where Enjoybot deep-cycle marine batteries come in.