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Old 12-13-2009, 07:20 AM   #11 (permalink)
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Ah, this was the thread I was hoping to find. I picked up a used 24' powerboat and I have a question. I apologize if it is completely clueless but I'm about to get on a flight and I wanted to ask something before I spent the better part of a day getting to the other side of the planet. I'm easily distracted so I wanted to ask before I forgot.

We also managed to snag an unused new-in-box 82lb thrust, 24v, saltwater, variable speed PWM wireless Motorguide electric boat motor.

I realize that the hull drag from a 24' boat will not break any speed records ... but it was more of an emergency backup means of movement should the main engine fail. Since we are on the Gulf of Mexico (and assorted back bays) an engine failure could be a life threatening (or ending) event. It would be nice if we could somehow limp back to shore or the boat ramp given enough time, favorable winds/currents/etc.

We also have a LOT of solar cells of various types and were looking to custom build a charging system using the front of the boat (not going to get into that here, but since the boat would be in the sun more often than not it would add something back over time)

Which brings me to my question. We were looking at various means of storage and I came across the LifeYPO4 batteries as listed on Assuming for a brief educational hypothetical moment that we had the funds to get the largest of what they had (see link below for specs), and assuming we could fit 8 of them in the boat in series for 24v ... would the cruising range be worthwhile doing running at the lower end of the power spectrum? With the hull drag I am more interested in being able to move as far as possible - it doesn't have to be fast.

Based on the specs below and the motor requirements, how many kWh is that anyway? 19200?

or the short version:

Nominal Capacity: 800Ah
Operating Voltage:2.5V - 4.25V
Weight:26kg 300g
Dimensions:850 x 288 x 71(mm)

I'm sure there is a whole slew of charging considerations that need to be factored in as well but first I'm curious to know if it would be pointless to go this route at all.

This project already has a lot of the big components. The boat is in excellent shape. The motor is in excellent shape and still under warranty. I have enough solar cells to fashion any sort of charging setup and could cover every available square inch of exposed surface and encapsulate them if it was practical. (specs on what cells I have can be discussed later, I'm more curious about the potential range of these batteries)

If anyone could share some thoughts, ideas, or comments that would be great. I don't know what the max amp draw on the motor though I did read somewhere someone had mentioned 40amps on theirs but I don't remember the details of their motor specs. I won't know more until I get back to where the motor is but maybe someone will have a rough idea.

Thanks for reading through this. I won't be able to reply for a day or two. My flight leaves in few hours.


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