T-Pain Is On A Boat: Re: [Electric Boats] Power Consumption for Minn Kota Riptide 50 & MotorGuide 54

Friday, September 25, 2009

Re: [Electric Boats] Power Consumption for Minn Kota Riptide 50 & MotorGuide 54

Hello
I would suggest you use 6 volt batteries (two in series for 12 volts), gulf cart size are readily available. You could use a total of four batteries two for each motor or a single series/parallel bank of four.   US battery Co. has a good selection and many distributors. You can also get 6 volt gulf cart batteries at Sam's club but I expect the US batteries are better quality. Check out there web site and contact local distributor to see what sizes they stock. You may get better price on ones that are in stock than ordering other sizes. They tend to stock specific sizes that are used in gulf carts.

I have used US battery for electric car with much larger bank than you will need. They are desinged for deep discharge.  The 6 volt batteries will hold up much better than using 12 volt batteries.

http://www.usbattery.com/usb_productline_main.html

http://www.usbattery.com/usb_index.html

http://www.usbattery.com/usb_config.html

Happy sailing,
George Kuck
Chestertown,Md.

--- On Fri, 9/25/09, cal29brad <bradley.a.bates@gmail.com> wrote:

From: cal29brad <bradley.a.bates@gmail.com>
Subject: [Electric Boats] Power Consumption for Minn Kota Riptide 50 & MotorGuide 54
To: electricboats@yahoogroups.com
Date: Friday, September 25, 2009, 5:12 PM

Hello to All,

I have a MotorGuide 54 that has these specifications:

12 Volts 0.34 Kwatts

I also have a Minn Kota Riptide 30 with these recommendations & specification:

12 Volts
105 Ampere/Hour Battery
"... your 12 volt motor with draw 1.0 ampere/hour ... for each pound of thrust produced when the motor is running on high."

By my calculations these work out to:

MotorGuide 54: (0.34 * 1000) / 12 = 28.33 ampere / hour

Minn Kota 50: 1.0 * 50 = 50.0 ampere / hour

Do those numbers look correct to all of you? The units and the pounds of thrust they produce are pretty similar, which makes me suspect the somewhat significant difference in the ampere/hour ratings.

All enlightening efforts are greatly appreciated. I plan to use these two units to move a Cal29 sailboat about six to ten miles across (or down) Boca Ciega Bay to downtown St. Petersburg Florida early next week, and need to calculate what size batteries I should get. The boat is not refitted yet, so I need to jury-rig all of this, including battery locations, cabling, breakers, and so on.

I have found a local firm that has what appear to be 85 amp/hr (they "rate" them thus: 205 minutes at 25 Amps each) 12 Volt deep cycle marine batteries currently on sale for about $60.00 each. Again, according to my calculations, three of those should give me either 2.5 hours (using the Minn Kota) to 4.5 hours (with the MotorGuide) of full speed motor use with about 50% battery consumption. Does that look correct?

Thanks much in advance,

Brad Bates
Play Mate
St. Petersburg, FL
(I am dangerous with a calculator)

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