northforktug130
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- Fluid Motion Model
- R-27 Classic
Does thursters use a lot of battery.
Thursters and battery
- Thread starter northforktug130
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venajeff
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Generally bow thrusters do draw high current but the length of time they are used is usually short. So the over all power use is not that much.
But this is coming from a traditionalist who considers a bow thruster is for extreme situations or when a mistake was made.
But this is coming from a traditionalist who considers a bow thruster is for extreme situations or when a mistake was made.
scross
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Thrusters, the windlass and your engine starter(s) are the biggest power draws on the boat. Your engine has a separate battery dedicated to starts.
In the old days your windlass and thruster shared a common battery separate from the house battery bank. More recently the windlass is tied to the house battery bank.
You can tell from the huge copper cable going to the thrusters that they draw a huge amount of power. Here’s a listing from SidePower showing the draw of their different models:
Examples of Current Draw:
venajeff
Well-known member
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Yes, bow thrusters do use a lot of current, thus battery ratings and wire gauge is critical.
As to the original question, I am making the assumption that "use a lot of battery" is referring to whether or not the bow thruster will run your battery down and leave you with a dead battery.
Using the specs of the SE100/185T thruster, which is larger enough for a 55' vessel. Lets look at the total power use:
740 A @ 12V running it at the maximum allowed time of 3 mins. (duty cycle is stated at 2 - 3 mins.) equates to:
740A x 12V x 3/60 fraction of hour = 444 watt hours
For reference the propane valve on my R27 draws about 1 amp, and if I leave the propane valve on all day that equates to:
1A x 12V x 24 hours = 288 watt hours
So assuming you use your bow thruster normally (less than a minute of use per docking) and you have a thruster smaller that the SE100 then I would be more concerned about turning off your propane switch than how much power consumption the bow thruster is using.
On a side note. I don't think people should be overly reliant on their bow thrusters. In my experience with bow thrusters, including my current R27, the bow thruster can rarely counteract a heavy wind. Boat maneuvering skills are absolutely critical in those situations and the best time to practice them is when there isn't a strong wind.
As to the original question, I am making the assumption that "use a lot of battery" is referring to whether or not the bow thruster will run your battery down and leave you with a dead battery.
Using the specs of the SE100/185T thruster, which is larger enough for a 55' vessel. Lets look at the total power use:
740 A @ 12V running it at the maximum allowed time of 3 mins. (duty cycle is stated at 2 - 3 mins.) equates to:
740A x 12V x 3/60 fraction of hour = 444 watt hours
For reference the propane valve on my R27 draws about 1 amp, and if I leave the propane valve on all day that equates to:
1A x 12V x 24 hours = 288 watt hours
So assuming you use your bow thruster normally (less than a minute of use per docking) and you have a thruster smaller that the SE100 then I would be more concerned about turning off your propane switch than how much power consumption the bow thruster is using.
On a side note. I don't think people should be overly reliant on their bow thrusters. In my experience with bow thrusters, including my current R27, the bow thruster can rarely counteract a heavy wind. Boat maneuvering skills are absolutely critical in those situations and the best time to practice them is when there isn't a strong wind.
Submariner
Channel Surfing
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I rarely use my bow thruster. With an F300 Yamaha on the back, it makes for a great stern thruster. A suicide knob is necessary to get from hard port to hard starboard quickly...
For example... Hard port in forward.... then hard starboard in reverse... and the boat keeps turning the same direction... the boat will literally spin on its center, 360 degrees doing this, without any bow thruster. It's nice that the Yamaha's all come with a rudder indicator too (look back at the engine and it's easy to see which way it's pointed).
Also, as far as power goes.. the refrigerator(s) are the largest daily loads on the boat (consuming about 45 amp-hours a day). The bow thruster, windlass, and engine battery are all used with the engine running, so while they're large loads for short periods of time, they're also used at the best possible times (with the engine running).