Topic: Battery in the gas tank

[jcote75]

Hi,

I will make a 4 inch stretch on my gas tank. While I have it open, I was wondering if it would be a good idea to make a location for the battery in the tank with a opening underneath.

Don't know if everybody is able the picture this idea? What do you think?

Thanks,
Jocelyn

P.S.: by the way............... yes the gas will be separate from the battery!!! 

[ProTeal55]

If you can make it work (and be safe) go for it.
A buddy of mine is doing something similar, but he split his stretched tank in 1/2, and is doing left side fuel, right side 1/2 oil tank and then a compartment for the battery/electronics..

[nickjtc]

As long as there is absolutely no way that gas fumes will accumulate anywhere near the battery it should work.

[bill440cars]

        I believe I'd think about the fact that "Batteries Can Explode". If you want to do this, it's up to you but, I'd think long and hard about it. Also, if the alternator starts overcharging the battery, you're gonna get some fierce smells and possibly corrosion ( are you talking a regular type battery or a get type?). If a battery explodes anywhere on a bike, it's not gonna be good but I'd rather have it behind me that right in front of (and right next to gasoline) me. Just something to think about.

                                                 Later on, Bill    

[jcote75]

Make sense. I'll put it in the back seat then.

Thanks very much for your help!

BTW, are there any thread to how to stretch a gas tank.

[ProTeal55]

Don't give up that easily !
Just used a quality Gel/Sealed battery and you will be fine (plus you can mount however u want).
No vent tubes - sealed construction - etc..

[eldar]

As another idea, you could whack off part of your tank and seal it back up for the fuel. In the area you whacked off, you can make a compartment for the battery with a door on the bottom(out of site) to access the battery. Then smooth is all out so the tank looks like normal. This should keep fuel and battery separate and still keep the looks of the tank.
Maybe this is what you meant anyways though!

[silver fox]

Why not? My other bike is a BMW R1150GS, and the battery is mounted directly under the fuel tank, and there is hardly any space whatsoever between the two, and it isnt a gel type battery. I suppose if its good enough(and deemed safe enough) for BMW, it should be good enough for us lot!!!!!

[SteveD CB500F]

BTW, are there any thread to how to stretch a gas tank.

You need to talk to DME.  Look up his build thread.

[Bodi]

"BTW, are there any thread to how to stretch a gas tank"

It's going to be very tricky stretching a curved/tapered tank without it looking goofy. The OCC idiots do weird stuff with tanks all the time - usually widening or narrowing though. You just cut it in half, make a steel bit to go in between the 2 pieces, and weld it together. But a tapered tank... you would have to discard the stock rear piece and make a complete new one with a different taper to get out to where you need it to "stretch". Forming a steel tapered/curved shape from sheet stock is certainly possible but you need some specialized tools and a LOT of skill and experience.
You might check the forums/faqs for a pretty detailed how-to on making a complete fibreglass tank using a foam inner form that you dissolve out with solvent after layering the glass cloth on the outside. This is possible for a home project, complex sheet steel shaping probably isn't.
Or chain the front and backof your tank to locomotives and really stretch it?

[andy750]

As Steve has said look up Daniels (DME) thread on stretching gas tanks. As I recall he used a second tank and cut off the part nearest the seat and fixed (somehow) this onto the primary tank creating a "stretched tank" but at stock capacity. By doing this you could achieve a battery compartment if the cut section was big enough. But look at the DME thread as he has lots of great photos describing this...and tank looks great!

Andy

 

[jcote75]

This is for a 1975 cb750f gas tank.


I'll check tonight if their will be any curving issues as you mention. Good point.

[TwoTired]

I saw the tittle of this thread and immediately thought "crash and burn".

I'm not sure if even the Hemlock Society would approve.  But, "going out in a blaze of glory" is preferred by some.

Best of luck!

[heffay]

Just used a quality Gel/Sealed battery and you will be fine (plus you can mount however u want).

not quite everyway... i remember the suzuki TL 1000's late 90s and early 00's had a sealed battery mounted on a pretty good tilt. 
even though it was a sealed battery... it wasn't sealed and they leaked all over the bikes... bad stuff
the bikes were recalled and a different battery (sealed as well) was used to replace the leaking ones.
no i don't remember the specific batteries but, i would at least recommend extensive battery research

[CrisPDuk]

I saw the tittle of this thread and immediately thought "crash and burn".

That's the trouble with you yanks, you're to timid

We Brits used to put multiple .50" machine guns in the fuel tanks of our fighter jets A battery in a motor bike fuel tank is kid's stuff

I'm with Proteal, don't give up so easily.

Personally speaking though, rather than mount the battery in a compartment in the tank, I'd mount it to the frame and use an open bottomed section of the stretched tank to cover it, same effect, but (slightly) easier to achieve. Plus, that way if you do get a leak it isn't going to eat your tank.

[Sam Green Racing]

If you can make it work (and be safe) go for it.
A buddy of mine is doing something similar, but he split his stretched tank in 1/2, and is doing left side fuel, right side 1/2 oil tank and then a compartment for the battery/electronics..

Your mate is going to have a very hot right leg/knee.

Sam.

[aptech77]

 

[Sam Green Racing]

Oil tanks get very hot.

Sam.

[kghost]

That's the trouble with you yanks, you're to timid

We Brits used to put multiple .50" machine guns in the fuel tanks of our fighter jets A battery in a motor bike fuel tank is kid's stuff

I'm curious which fighters had .50 cal's in the wing tanks?

The gold wing has the battery adjacent to the fuel tank which is under the seat on the gl1000.

Its slightly aft of the tank but within 4 inches.

I don't think I would put the oil in one half of the gas tank without some sort of double walled tank. Possibly some ceramic coating as well.

[CrisPDuk]

I'm curious which fighters had .50 cal's in the wing tanks?

To my knowledge, no fighters had guns in their wing tanks


But several variations of the English Electric (later BAe) Lightning had four Brownings mounted in the front section of their belly tanks



Out of curiosity do any jet engined fighters have wing tanks?  Drop tanks don't count

[bill440cars]

   CrisP, The F-4 Phantoms had fuel bladders in the wings, so I would think that there are others, though I'm not sure which ones.

                                                        Later on, Bill

[mgmuellner]

Many new bikes come with batteries under the tanks - ducati's & bmw's come to mind.  They wouldnt do it if their lawyers thought they'd be killing customers.  A gel battery would be a must.  I have never heard of batteries blowing up - except for cell phone batteries.  If one did in it's stock location - it'd take your most special bits with it.  If the battery exploded in a cafe hump, you'd probably go #2 out of a tube for the rest of your life.  Each place you put it has some consequence.

[TwoTired]

   CrisP, The F-4 Phantoms had fuel bladders in the wings, so I would think that there are others, though I'm not sure which ones.

                                                        Later on, Bill

The F-4 Phantoms also had no airframe mounted guns.  Lots od missle and hard mounts, though.  So, during the Vietnam War they were fited with converted drop tanks that carried guns (but no fuel) so they could do ground straffing runs.  When the VC started shooting small arms up the Phantom's tailpipe on climbout (downing planes) they mounted two converted drop tanks, one with guns facing forward and one with guns facing rearward.

I'm not aware if the english electric Lightning drop tanks (are these drop tank style?) were fully converted or still had containment for fuel.  Seems there might be a problem with the gun recoil wreaking havoc with the fuel interconnect seals and leaving you with afterburner in an undesigned location.

Cheers,

[kghost]

Later model Phantoms had guns as bill can confirm.

Many new bikes come with batteries under the tanks - ducati's & bmw's come to mind. They wouldnt do it if their lawyers thought they'd be killing customers. A gel battery would be a must. I have never heard of batteries blowing up - except for cell phone batteries. If one did in it's stock location - it'd take your most special bits with it. If the battery exploded in a cafe hump, you'd probably go #2 out of a tube for the rest of your life. Each place you put it has some consequence.

Batteries can and do blow up ...They vent hydrogen gas. Think Hindenburg.

[KB02]

Many new bikes come with batteries under the tanks - ducati's & bmw's come to mind.

That's true. On my Ducati Monster, in order to get to the battery, I have to lift the tank (It's cool, for those who don't know it's got a hinge and prop rod and everything). The coils are attached to the battery box as well. It's just a standard lead acid battery, too. And my Father's Yamaha Venture has the battery right in the Fake tank, just above the gas cap opening (Tank actually under the seat). To my knowledge, neither design has ever had any problems with these set ups.

Personally, I like the idea of the battery being in the stretched tank. Just do your homework on the design.