How to size an electric motor for a boat?
RECOMMENDATION: You need at least 2 pounds of thrust for every 100 pounds of fully loaded boat weight (people and gear included). If things like wind or current are major factors where you fish, you’ll want a little extra thrust. I’d say at least a 40 horsepower, 50 if you go with a fourstroke. The horsepower rating plate usually limits you to too low of horsepower if you have the boat loaded with near maximum weight. I had an alumacraft 14/56 that was rated to 25 HP tiller steer.For every forty pounds of boat weight, you need one horsepower to motor along over smooth waters at 20 miles per hour. So, for a 4,000-pound boat, that’s 100 horsepower for smooth, steady cruising. For an 8,000-pound boat, that’s 200 horsepower.
Can you use a lithium battery for an electric boat motor?
Smaller batteries are revolutionizing the marine industry, delivering superior performance and efficiency for trolling motors and other marine applications. Switching to lithium batteries can also help reduce the weight and space in your battery compartment, improving overall performance. Many deep-cycle marine batteries on the market today are designed with dual-purpose capability. If you have a smaller boat with a less demanding engine, a quality dual-purpose deep-cycle marine battery might be sufficient to start the engine and power accessories.Lithium Batteries Lithium marine batteries are the most recommended type of boat battery for trolling motors. Specifically, the best ones would be lithium iron phosphate batteries or LiFePO4 batteries.
What size battery for electric boat motor?
We suggest selecting a 12-volt deep cycle marine battery with at least 110 amp hour rating. Usually Group 27 size or larger. The higher the amp-hour rating, the more run time your trolling motor will receive. The runtime of a 100Ah battery on a trolling motor depends on the motor’s amp draw and how fast you’re running it. As a general estimate: At full speed, if your motor draws 50 amps, a 100Ah battery would last about 2 hours. At half speed, drawing around 20–25 amps, it could last 4–5 hours.