Calculating Motor Run Time
The second factor we need to compute estimated run time is motor amperage draw, which is how much current a motor draws at a given speed. For example, marine batteries are rated on a metric called “amperage hours,” which is an indication of how long a battery can supply a consistent amperage. The larger the rating, the more power the battery can hold and the longer it will be able to power a motor.
Considering Weather Conditions
In calm conditions, a motor drawing 020 amps to move a boat at medium speed may require 30 amps in windy or stormy seas and water conditions.
How many amps does my trolling motor draw?
The 50 lb thrust trolling motor has a maximum amp draw of 52 amps/hr, but only 5 lbs more thrust. 3. Lower speeds use less amperage for the same thrust due to the larger windings in the 50 lb thrust model.
How do you calculate amp draw on a motor?
You can usually find this information on the product label or in the owner’s manual, and then divide the wattage by the voltage (100 watts / 12 volts = 8.33 amps). This will give you an estimate of how much current your equipment will draw.
What size battery do I need for a 40 lb thrust trolling motor?
We recommend a 12 volt deep cycle marine battery with at least a 110 amp hour rating, usually a group 27 size battery, because most trolling motor batteries fail due to improper charging.
How long will a 100Ah battery run a trolling motor?
For 4 hours, a 100Ah lead acid deep-cycle battery will power a 30lb thrust trolling motor on Speed 4.
How many amps is considered a parasitic draw?
A parasitic draw test requires a Digital Multi-Meter (DMM) that can handle a minimum of one milliamp and up to 10 amps.
What is the formula to convert HP to amps?
Because the SI unit of power is the watt, it’s common to convert units before estimating amperage. A rule of thumb is to multiply the power in hp by 746 to get the power in watts.