Battery placement in an 18?

[Kirbyvv]

I'm about to pull the X-18 out of storage and am getting ready to pull the deck to replace the tank. While the deck is off I'm going to clean up the inside of the hull, etc. Is there any advantage or disadvantage to relocating the battery to the engine compartment? Right now it is under the back seat, where it is out of site and out of the way.

[mattyboy]

Kirby how do you feel the boat rides???

is the battery mounted on the centerline??

that might be tough to keep it on the centerline the farther you move it back

if it leans move the battery for ballast

if it rides the way you like leave it where it is

[Kirbyvv]

Matty, that's exactly what I was thinking. It rides nice where it is. I just didn't know if there was an advantage to moving it back.

[BlownCrewCab]

if you have two batteries then there is an advantage putting one on the port & one on the stb, Imagine a dumbell as wide as your boat, now slide the weights all the way to the middle, you'll be able to "Sea-Saw" the bar easily and quickly, slide the weights all the way out and it becomes several times harder to get the bar to "Sea-Saw"....So the farther outboard from the centerline you mount them (or any other equipment like trim pumps etc) the better more stable ride you will have. same goes for weight fore & aft if you want to fly level, but thats allot more work.

[hardcrab]

BCC : That's a good analogy - :kingme:

I would've been inclined to keep 'em both low and center

[BlownCrewCab]

For single Battery low and centered is good, or far outboard from center on the passenger side and mount the trim pump(s) on the opposite side.

[MOP]

I have several discussions with Geo on weight transfer, he and I now are adamant about moving as much aft as possible. Using his thinking I went to dual batteries and moved them into the engine bay just behind the seat, I just bought the materials to move them all the way back. What many do not understand or want to acknowledge is Donzi had to make some concession in the design to please a broad range of buyers, thes hulls run faster with weight aft. To accommodate a ski locker. IMO the tanks are mounted too far forward, both GEO and I have the fuel tank aft just ahead of the engine. Look at his video which was recently posted, look at how nice the boat flies when airborne. It surely is not out of balance CG wise, most are worried about getting weight out of the engine compartment when really more should be moved back there. Also nothing should be stored forward if you want that last little bit of speed!

[mrfixxall]

When i restored my x i moved the battery to the engine bay...i glassed in a piece of 3/4'' birch plywood in each corner of the boat from the first gusset that's even with the front of the engine to the transom. then mounted my battery's on each side..the old battery compartment makes a nice storage area now.i mounted a battery switch where the battery use to be..if you decide to keep the battery in its current location check the bottom of the compartment,they have a tendency of blowing out then the battery falls into the hull..

[Donzi Vol]

I'm really glad that this thread started because I am planning to go to dual batteries and move them in the engine compartment as well. I've already discussed with several on here, and all votes (including these) lead toward doing it. I'll be measuring tomorrow as to what to put where...

[mattyboy]

sweet cheeks has a lot of weight moved fwd it is by far the smoothest riding 16 I have seen running at those speeds.

it is important to note what might work for one classic might not for another. an X 18 with an arney is different from a small block 22 from a mid 70's stock volvo x 18 to a 550hp 16.

Kirby if you like the way the boat rides now leave the battery where it is. you can always try throwing a sandbag in the back to see if it has any improvement .

[gcarter]

Kirby if you like the way the boat rides now leave the battery where it is. you can always try throwing a sandbag in the back to see if it has any improvement .

I agree!

[MOP]

A flat running Deep V is slower then a nose up deep V, so simply proved just run WOT with no trim then trim up. Six MPH difference on my setup, looking at sweet cheeks he was not in ideal conditions to fly the bow. In ideal conditions his boat will do a bit better, in one section of the video you can see the water patterns off the tabs we all know that scrubs speed. That beautiful beast has some punch left!

[mattyboy]

Phil,

yes on your 22 and in general that might work. BUT I have seen in person Parnell run up at lake george he has added weight up front between the seats the tank .
the 16 rides better with more wetted surface and it will run faster and be able to maintain faster speeds longer than a 16 and it's quirks when it is aired out. they were not optimal conditions but even at 60 or 65 you can see the boat tracks true no quirks . the 16 is different from an 18 or a 22
I can see an x 18 with an arney needing weight in the back and rocker plates to get the bow lift it needs . or your small block 22 might need weight as there is usually more weight in a BB 22.

I saw sweet cheeks not at her best her shakedown tour he had a motor issue, but I saw enough to know the boat will run at speeds no 16 except maybe what rootsy did for a extended periods in not the best conditions. That was accomplished by adding the right power drive combo along with the weight up front I would say take the motor out and add it to a normal 16 and you'll have a white knuckled nightmare.

Parnell will get that 16 into the 80's without a doubt even when he airs it out a little more it will still have more wetted surface than a normal 16.

when it comes to the classics they are not all the same what works for one boat might not for another . so making blanket statement doesn't cut it.
a prop that works on one boat might not for another. Dr Dan's 22 is another example it has a different angle of attack then other 22s.
I've seen it run with other 22 from different eras. it has a flatter more level angle of attack and when the spurs are put to it in sloppy conditions aired out 22s have to get out of the stick while dan can keep the power to it.

ask Buzilla about the difference he felt it hopped out of dr dan's boat a 93 and into a 04 anniv edition he could tell the difference right away in the feel of the boat and it's ride.

I agree it's water , basic physics laws of drag mean the less boat in the water faster speeds but in some cases you have to dance with the devil.

the differences in lay up, construction methods and results from day to day, x dim,imperfections in the hull from premature ejection from the mold
make the boats all different. especially on the 16 as the strakes are totally different from an 18 and 22.

ask anyone running a solas on a 16 they might have props that are faster but they can't stay at those speeds for any given time. the solas has limited bow lift it flattens the angle of attack and settles the boat down so that the power can be applied .

[MOP]

Matty agree with most all you said but remember I had a 16 for three years, the difference in speed between trimmed and untrimmed was a lot, do they get spooky yes but faster. True any boat will run a bit smoother flat but not as efficient/fast. At almost any planning speed you can fool with the trim and gain speed, I do run flatter when cruising but still have some trim on. It is just plain silly to run flat when you don't have to! Do the test run @ 3000 note your speed then tickle the trim up you should see about a two MPH gain kind of dumb not to take advantage of that. Most all without trim would truly love to have it, between drive trim and trim tabs a boat becomes far better mannered and faster.

[mattyboy]

Phil

we are not talking about mid crusie and what trim does we are talking about getting a 16 running above 65 70 mph . when you had your 16 what speeds did it loosing up?? do you really think moving the weight back would help ride or speed.

also I am talking about maintainable speed not short bursts. Look again at the video he is running 60 65 mph with ease 3 passengers you can count on one hand 16s that run that speed that stable. That is cause the weight has been moved forward not back
my 16 ran the fastest with nuetral trim and slight bow lift It did not need trim. I put 8 years into that boat trying to get it to run right the boat ran the worst trimmed up yeah it was fast 65mph but i could only stay there for seconds more like 50 mph controlable after that it got to loose. once flattened out, propped right I could run 58-62 mph all day in most conditions very controlled and stable.

[oledawg]

Only comment that I have on this is that on my C22 the battery is under the back seat in a "closed" compartment and my mechanic said that was for a reason, to keep any chance of sparks away from potential fumes in the engine bay. In fact he wouldn't even install a Perko battery switch in the engine compartment for the same reason, insisted on mounting in the battery box. Said regulations wouldn't allow it. Thoughts?

[Sweet Cheekz]

Phil

also I am talking about maintainable speed not short bursts.
.

Obviously I agree with Matty but this is the most important point h made as far as I'm concerned. Since most of us rarely get dead flat water with o boats around I would give up a few miles an hour to run faster and safer in a chop and a little weight forward is going to do that in most cases. Interesting discussion as always
Parnell

[Sweet Cheekz]

if you have two batteries then there is an advantage putting one on the port & one on the stb, Imagine a dumbell as wide as your boat, now slide the weights all the way to the middle, you'll be able to "Sea-Saw" the bar easily and quickly, slide the weights all the way out and it becomes several times harder to get the bar to "Sea-Saw"....So the farther outboard from the centerline you mount them (or any other equipment like trim pumps etc) the better more stable ride you will have. same goes for weight fore & aft if you want to fly level, but thats allot more work.

Seems like a good point although both my batteries are on the starboard since I drive from the port
Parnell

[BlownCrewCab]

Seems like a good point although both my batteries are on the starboard since I drive from the port
Parnell

Kinda the same thing, just with bigger mass which probably works even better, the more bigger masses you mount far outboard off the center line the less wiggle you get, you can make chinewalk a thing of the past by setting up your boat correctly. you seem to be about there:yes:

[mattyboy]

interesting topic, I am up in the air on how the hornet will ride it has a new belly tank under the benchseat the old nose tank has been abandoned. the previous owner had storage boxes made outboard of the stringer on each side of the motor. I was going to remove them but they make a nice seat when you work on the motor. so I'll see how she rides and if she walks I can fill up the boxes. :)
this is a much bigger boat that my 16, a much bigger wider flatter bottom

[Greg Guimond]

Isn't it generally agreed that the best angle of attack is considered to be 3-5 degrees for small V hulls like the 16 and 18? I'd suspect that when you get to the 22 you want to carry the bow a touch more.

[mattyboy]

Only comment that I have on this is that on my C22 the battery is under the back seat in a "closed" compartment and my mechanic said that was for a reason, to keep any chance of sparks away from potential fumes in the engine bay. In fact he wouldn't even install a Perko battery switch in the engine compartment for the same reason, insisted on mounting in the battery box. Said regulations wouldn't allow it. Thoughts?

just a side note here, I just got out of the bilge of my boat the battery switch is mounted on the back of the benchseat it is labled as sealed and explosion proof wonder if all switches are like that?? there is no make or model on it that I can see. my batteries will be mounted on a board in the bilge that runs across the stringers. they will be in plastic battery boxes strapped to the board . the boxes have tops on them , with the tops on I would think sparking would only occur when connecting them with the top off. which means you would be in the bilge and would be aware of any excess fumes. I can see when jumping or charging a battery it being easier and safer to lift the seat cushion and just hooking up to the battery and not worrying about getting in the bilge or the fumes.

[Sweet Cheekz]

As another side note I'm putting my batteries in the engine room but putting a jumper switch in the cockpit so a dead battery will open the hatch and start the motor without being in the engine room at all. Another option to consider for some.
Parnell

[mrfixxall]

Here's a tip for people running battery's in the engine bay! If your using the wing nut's to hold the battery terminals on your battery's take them off and throw them away..Go to your local hardware store and replace them with a nylock stainless steel nut and crank down on them so the battery terminals wont come loose,this way no spark can occur :)

[Bobby D]

Kirby,
FWIW when my boat was restored Andy did what Mr Fixxall described. He installed light weight honeycomb panels in the engine compartment port and starboard side and installed duel batteries. He also enlarged the old battery box and it’s now a nice beer box and installed a 40 gal gas tank. Can’t comment on handling because I don’t know how it handled before the mod and I am still learning to drive it however when the batteries need to be replaced I will go with only one on the starboard side. Bottom line the boat gets up and goes and handles great in the rough stuff. Pictures are not that good but you get the idea.
Bob

[MOP]

Only comment that I have on this is that on my C22 the battery is under the back seat in a "closed" compartment and my mechanic said that was for a reason, to keep any chance of sparks away from potential fumes in the engine bay. In fact he wouldn't even install a Perko battery switch in the engine compartment for the same reason, insisted on mounting in the battery box. Said regulations wouldn't allow it. Thoughts?

As most know I have been in the industry for about 50 years, spread between being a mechanic a boat broker, been boating since I was six I have been aboard most all types and sizes afloat!

IMO were smoked by someone with little knowledge or spewing his personal view!

There are only few boats of any size that do not have their batteries and switches in the engine compartment, yes you will find many with the switch accessible from outside the compartment. But look where the back of the switch is, yup in the compartment, first off marine switches are are spark proof. Most insurance companies require battery boxes not just hold downs! All regulatory groups insist on non sparking electrical equipment and proper ventilation, follow the rules and you will not have issues!

[silverghost]

I agree with MOP~
All quality UL-listed marine battery switches are sealed & spark-proof.
I have cut open Perko & Guest switches and they are glued together or use O-rings for sealing.
They are designed for bilge and closed compartment use.
I like the switches that contain a built-in alt. field disconnect. This prevents diode & regulator burn-out if swtched when engine is running.
This can be a costly mistake to make with a standard switch.
Just a extra pair of #14 field wires from the switch to your alt's field teminal .

[Donzi Vol]

Kirby,
FWIW when my boat was restored Andy did what Mr Fixxall described. He installed light weight honeycomb panels in the engine compartment port and starboard side and installed duel batteries. He also enlarged the old battery box and it’s now a nice beer box and installed a 40 gal gas tank. Can’t comment on handling because I don’t know how it handled before the mod and I am still learning to drive it however when the batteries need to be replaced I will go with only one on the starboard side. Bottom line the boat gets up and goes and handles great in the rough stuff. Pictures are not that good but you get the idea.
Bob

Bob, can you elaborate more on the honeycomb panels? That's where we're at right now on mine...finding the right material to use. Thanks -David

[Bobby D]

Found this information on the internet it's similar to the ½ inch material installed in my boat. By the way it's also installed in the bow where the ski locker was as well.

Google this:
Plascore Board™ is a stiff, lightweight panel designed to add strength to primary and secondary structures. . . while saving time and reducing labor on the production floor. Plascore Board is manufactured to tight tolerances and is easy to cut, shape and drill for cabinetry doors, hatches and shelving; easy to veneer or finish as a Class A surface. Available in a range of honeycomb cores with performance facings, Plascore Board offers an exceptionally high strength-to-weight ratio, making these value-added panels an ideal substitute for marine grade plywood in sub-paneling, bulkheads, decking/ ceilings, sun shades and swim platforms. Thermal and acoustical insulation is excellent; water absorption is minimal or non-existent.
Designed to add value in boat manufacturing, Plascore Board panels are available cut to a custom size or shape, or in a standard sheet size of 48" x 96" in a thickness of 1/2", 3/4" and 1".

[VetteLT193]

Matty/Parnell: what's the overall weight of Sweet Cheekz Vs. a standard 16? I suspect is partially balance and partially overall weight that causes that little beast to run so well.

[DickB]

I agree with MOP~
I like the switches that contain a built-in alt. field disconnect. This prevents diode & regulator burn-out if swtched when engine is running.
Perko switches are make-before break type, and the order is 1-both-2, so you never have no battery connected during switching unless you go to "off".

[mattyboy]

Parnell can probably give you exacts

but the weight added forward comes from the 2+2 custom seats and console and the extended forward 65 gallon gas tank. Parnell moved the fwd bulkhead that holds the tank and the lift ring. All of this is added weight over a stock classic , sweet ,or skisporter 16 with 2 regular buckets or a bucket and bench seat and a 25 or 45 gallon tank.

I realize the general concept of get it aired out and fly it. That holds true on the 18 and 22 as they can ride on the radius keel with some of their inner lifting strakes still getting wet. The 16 once it is aired out really has nothing but the radius keel wet, and it can depending on prop chine walk a little or gunwale walk alot. The inner strakes on a 18 or 22 end much closer to the transom than a 16, the 16 inner strakes stop around 3 feet from the transom. I have not looked at a post 1990 sweet 16 bottom to see if that was changed. The molds for the skisporter 16 were long gone by then and supposedly the new sweet 16 was mold was pulled from a splash being made at the time. so the bottoms could be different.

wonder if someone with a 1990 or newer 16 can take a measurement.

sweet cheeks is a 79 skisporter so it has the short inner strakes.

I did notice that my hornet hull except for the increase in beam and the decrease in deadrise is very similar to the 16. Rounded keel short inner strakes and a slight intentional hook out by the chine

[Donzi Vol]

Found this information on the internet it's similar to the ½ inch material installed in my boat. By the way it's also installed in the bow where the ski locker was as well.

Google this:
Plascore Board™ is a stiff, lightweight panel designed to add strength to primary and secondary structures. . . while saving time and reducing labor on the production floor. Plascore Board is manufactured to tight tolerances and is easy to cut, shape and drill for cabinetry doors, hatches and shelving; easy to veneer or finish as a Class A surface. Available in a range of honeycomb cores with performance facings, Plascore Board offers an exceptionally high strength-to-weight ratio, making these value-added panels an ideal substitute for marine grade plywood in sub-paneling, bulkheads, decking/ ceilings, sun shades and swim platforms. Thermal and acoustical insulation is excellent; water absorption is minimal or non-existent.
Designed to add value in boat manufacturing, Plascore Board panels are available cut to a custom size or shape, or in a standard sheet size of 48" x 96" in a thickness of 1/2", 3/4" and 1".

Thanks! I'll check on it.

[Sweet Cheekz]

Matty you got all that right.
I tested today in freaking hurricane 20-30 mph winds with a big chop on Spring Lake in MIchigan and I was really glad I had some weight forward cause it was bumpy for a 16. Perfect day to show why some weight forward is not a bad thing.

I ran out of lake each time and really had to pay attention but the bow stayed down and I was able to raise my bar a bit. Prop testing next week to find those last 900 rpm's

[Sweet Cheekz]

Matty/Parnell: what's the overall weight of Sweet Cheekz Vs. a standard 16? I suspect is partially balance and partially overall weight that causes that little beast to run so well.

Just saw this Vette I have not weighed it but I will this spring I am very curious about that.
Parnell

[jl1962]

Matty/Parnell-

Do you think extending the inner strakes on a 16 aft, or even adding a small skeg on the center line would have any positive impact on handling? I agree about a full tank and even passengers settling the boat down.
Jay

Parnell - 77MPH w/ 900 rpms to go? :shocking::nilly::nilly:

[Sweet Cheekz]

JAy
I will leave the theory stuff to Matty since I beleive its one of his specialties but I eagerly await the comment! Prop testing Monday to find those r's
Parnell

[Sweet Cheekz]

. Parnell moved the fwd bulkhead that holds the tank and the lift ring.

BTW This forward bulkhead is really a full bulkhead now from side to side and bottom to deck It added something.

Does anyone know if there is a limit on how far from the batteries you can run the battery switch?
Parnell

[Just Say N20]

Depends totally on the gauge of wire used to run the distance.

In my Reflexx 175 I used 1/0 gauge, and the cables were 12' from the battery to the switch, without problem.