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Relocating batteries from back to front

DVW said:
Good idea if you can do it. I would be surprised if you can.
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Sorry if it sounded like I was questioning your capability. I am not. I would be surprised if Bennington left enough room in front of the transom to move the center tube back two feet.
 
Vikingstaff said:
I just start to wonder if you would be better served by simply selling your current boat since you don’t like the compromise hull performance and just going with a pure tritoon?
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Yes, I've considered that option, as well as replacing the center toon. To sell the boat and buy another would cost me around $30K or more. A replacement center toon would be around $5K according to my dealer. I'm still mulling over my options. I'll probably just learn to live with it, but I may try see what I can do on my own. I'm definitely going to move the batteries, because that does help. I'd like to also relocate the gas tank, but I think that's going to prove to be a bit more problematic. Lastly, I may investigate the possibility of shifting the center toon aft by one cross support if there is room.
 
I can relate to everything you are doing and your motivation to do it. The act of making improvements to your boat creates rewards that is greater than just buying a better boat. Attached photos show my project boat up north. The project used almost all the parts that I tore off my new Bennington down in the cities. Everything in the rear and below deck is new. The new two foot longer tubes where mounted to give the boat a more level stance. This stance reduced wave induced pitching at slow cruise speeds while trading off top speed. All this makes no sense on a 30 year old boat unless I consider personal rewards. Then it is worth every penny.
 

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Moving weight forward creates more wetted surface while running. My guess is you will lose some fuel efficiency and speed at all RPMs by doing so.

I would datalog your hulls performance at 500RPM increments recording RPM, speed and MPG/GPH in original configuration, then with the batts forward. See which is better and go from there.

The ONLY time I want the bow down on my boat while running is when the bimini is up - it catches air like a sail and actually slows me down unless I trim the bow all the way down. Hurts fuel and speed fairly significantly (3mph ish) but on those hot days with company, comfort is the primary objective.
 
Potomacbassin’ said:
Moving weight forward creates more wetted surface while running. My guess is you will lose some fuel efficiency and speed at all RPMs by doing so.

I would datalog your hulls performance at 500RPM increments recording RPM, speed and MPG/GPH in original configuration, then with the batts forward. See which is better and go from there.

The ONLY time I want the bow down on my boat while running is when the bimini is up - it catches air like a sail and actually slows me down unless I trim the bow all the way down. Hurts fuel and speed fairly significantly (3mph ish) but on those hot days with company, comfort is the primary objective.
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Much of my time spent on the lake is at either really slow speeds or totally stopped and swimming or having lunch/diner. I'm not nearly as concerned about losing a bit of speed, but I do need the boat to be more level in the water when I'm sitting still. I don't like when I'm stopped and the bow is pitched up at a high angle and the rear is nearly in the water.
 
The design of anything that moves thru a fluid like a boat or a airplane involves a lot of trade offs. A drag reduction modification made to my boat in the cities moved the center of gravity rearward. This created a bow high attitude that parted the water with more elegance and also created lift at speed. Another benefit of a higher bow is the ability to withstand the huge wakes from the wake board boats popular on our lake in the cities. The tradeoff is reduced visibility and a boat that pitch’s and bobs when it hits big wakes and even large waves at slow speed. On the boat up north I went the other way by mounting new tubes rearward. This moved the center of gravity forward creating a level stance that pushed the relatively blunt nose-cones deeper into the water. That reduced big wave induced pitching at slow cruise speeds for a better ride. The trade off with the bow deeper in the water is drag and the chance of a big wake breaching the deck. Boat design has a lot of tradeoffs.
 
DVW said:
The design of anything that moves thru a fluid like a boat or a airplane involves a lot of trade offs. A drag reduction modification made to my boat in the cities moved the center of gravity rearward. This created a bow high attitude that parted the water with more elegance and also created lift at speed. Another benefit of a higher bow is the ability to withstand the huge wakes from the wake board boats popular on our lake in the cities. The tradeoff is reduced visibility and a boat that pitch’s and bobs when it hits big wakes and even large waves at slow speed. On the boat up north I went the other way by mounting new tubes rearward. This moved the center of gravity forward creating a level stance that pushed the relatively blunt nose-cones deeper into the water. That reduced big wave induced pitching at slow cruise speeds for a better ride. The trade off with the bow deeper in the water is drag and the chance of a big wake breaching the deck. Boat design has a lot of tradeoffs.
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Agreed. It is all about trade offs. I'd just like to make my boat with the express tube sit in the water at an angle that is more like a standard tritoon does. This express tube setup makes it sit way to bow high.
 
Berf said:
Agreed. It is all about trade offs. I'd just like to make my boat with the express tube sit in the water at an angle that is more like a standard tritoon does. This express tube setup makes it sit way to bow high.
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Yet, that is the known tradeoff with the express tube. To get closer to tritoon performance without the full tritoon cost, the express tubes is that trade-off hull to achieve that. It has less drag with less center tube construction/aluminum/water contact to get improved performance. BUT…it sits on a more extreme angle, etc, etc….

Trade-offs for sure.
 
An observation from last week. It may be unique to the elliptical tubes. Had the boat running at 3400 rpm (16mph) in a light chop. Had the trim up a little bit. Most of the nose cones out of the water. Jill went from the seating next to me at midships to the front chair. The bow lowered slightly and the boat speed increased .75 mph at same rpm. It happen several times during the week. The only thing I could think of is the elliptical tubes are 32" ovals. That is a lot of wetted surface. Maybe with the nose cones now splitting the water it decreased drag. Don't know the why but I watched the gps speed increase on the chart plotter.
 
Remediation said:
An observation from last week. It may be unique to the elliptical tubes. Had the boat running at 3400 rpm (16mph) in a light chop. Had the trim up a little bit. Most of the nose cones out of the water. Jill went from the seating next to me at midships to the front chair. The bow lowered slightly and the boat speed increased .75 mph at same rpm. It happen several times during the week. The only thing I could think of is the elliptical tubes are 32" ovals. That is a lot of wetted surface. Maybe with the nose cones now splitting the water it decreased drag. Don't know the why but I watched the gps speed increase on the chart plotter.
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My guess is that as the bow lowered the stern raised, decreasing draft resulting in less drag.
 
Remediation said:
An observation from last week. It may be unique to the elliptical tubes. Had the boat running at 3400 rpm (16mph) in a light chop. Had the trim up a little bit. Most of the nose cones out of the water. Jill went from the seating next to me at midships to the front chair. The bow lowered slightly and the boat speed increased .75 mph at same rpm. It happen several times during the week. The only thing I could think of is the elliptical tubes are 32" ovals. That is a lot of wetted surface. Maybe with the nose cones now splitting the water it decreased drag. Don't know the why but I watched the gps speed increase on the chart plotter.
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When I moved a person from midship to the front of my boat the top speed decreased 2 mph. Another observation is that when I slowly increase speed with slow throttle input at about half speed the bow will lower and the boat will increase speed without significant throttle input. It feels like it is getting up on plain but it is not. That feel has more to do with the impact made by the bow wake. If you lay on the deck and look at what is going on below deck it starts to make sense. There is a lot going on below deck and it is not pretty.
 
Berf said:
I have the dual battery set up on a 22S Bennington with the half length center tube and a 150hp Yamaha. It sits way too low in the rear and I want to redistribute some of the weight to the front so it sits better in the water. I can buy battery relocation wires and extend the wires easily enough and move the batteries from the rear to the front, which would essentially shift nearly 100 lbs forward.

I'm just wondering if anyone else has been down this road, and if there is any reason not to do it.
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Back to your original thought. Here is a photo of my batteries relocated forward. All I needed was to extend the motor battery cables to make it to the front. The harness between the console and battery was relocated with no extra length required.
 

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