I wanna use a smaller battery

[Blain73]

I am doing a cafe racer build, and want to relocate my battery. My ultimate goal is to move it to under the tail, so I'm going to need a much smaller one. Any suggestions will be welcome. No worries I will be posting pics as the build progresses.

[TOOLS1]

Welcome to the forum. Looking forward to see your build. I am not sure about which battery would work. I know if, you are only going to use the kick starter, you do not need as big of battery. I would go someplace like Battery's Plus, and talk to someone in the know.
TOOLS

[Re-run]

I would go no smaller than a 7AH battery. I would also do an agm battery. I know some use a lithium of some sort but I don't know about them.

Another thing you can do is to make a mount behind the engine and in front of the rear tire. Use a thin aluminum case to guard it from rocks and such. Lower mass to keep the center of gravity lower.
Then change out the oil tank for a custom one that is easier to hide or is round.

I know many do cafe bikes for looks but they were also minimalist bikes. So look for ways to drop weight, keep the CG low and hid things as much as you can.

[shinyribs]

You know,this brings up something i was thinking about a while back. You see dirt bikes that have headlights,a kick start and no batteries on them at all.I dont know all the particulars,but a bike that doesn't require ANY battery would be sooo nice. I used to have a KTM like that.The head light was somewhat bright,not very.Just enough to dodge a tree with.Hmm...i betcha Piute could figure it out if anyone could

[Piute]

  .Hmm...i betcha Piute could figure it out if anyone could
 
  I believe I was just put on the spot,

1st off are you going to be actually racing this bike on the track or are you just looking for the look like most
  Oops welcome  and just enjoy your build no matter what,
 There is plenty of room in the back under the cowl, My F2 has a Lil tool box back there that I plan on cutting up and supporting to hold my reg. batt..Just to make room to move my oil bag inside the frame(1 inch).But I do custom fiberglass for fun and love a challenge.
  If you have the cash or patient to wait on and find part peace by peace and pray there good,Do it right and put in a magneto,I would definetly do if I could,but this includes complete new ignition stuff,there again buy-out new 1 place all at once but going to cost,or peace by peace again.
  Blain is your bike a 73 ? Is it runing good now ? How many miles on it ?,does it need a bore any how ? Pictures are nice but good info gets better results.Personaly I don't know all the ins and outs of the 750 but with this forum and others a person can build what ever it is they are thinking of.
   One last thing riding lawnmowers are 12 volt and have real small batt. but don't last..

[TOOLS1]

I know on some bikes, you can use a battery eliminator, But it would be next to impossible to run a CB 750 battery-less. The charging system must have some voltage to activate it. That's why, you can not start them if the battery is totally dead, or removed. I do think Cycle-X has a kit to make them battery-less, but it is expensive. One of the cleanest solutions I have seen is to mount a small AGM battery in the starter cavity.
TOOLS

[shinyribs]

Tools= makes sense

Piute=no   not putting you on the spot

[Piute]

                                  whole electrical is a great read

http://www.cyclexchange.net/Elec%20System%20Comp%20Page.htm

[Re-run]

The ktm, and other bikes, have what is called a magneto. A magneto uses a permanent magnet whereas the cb uses an electro-magnet.

[shinyribs]

Right you are Rerun.And the magneto on those bikes are tiny compared to what we have.I wonder if you could fit one inside the stator cover??That would be sooo sweet! Kick it and forget it!

[Blain73]

Thanks for all the input, I think I may have found a battery, it's a gell cell that is about a third the size of the original with 14ah, is that going to be too much? The reviews are pretty good with 54 reviews at 4 1/2 out of 5 stars. Oh, don't think I can go with a kick start its a 1982 DOHC, can't move the oil tank either, and don't worry pics are on the way.

[shinyribs]

Its not too much.You can never get too many amp hours

[Re-run]

I think 14 is standard, I know it is on mine. I have done a 7 on my bike still using the electric. I don't buy the not running the starter thing. Reason is that if you bike is tuned, it will start in 1-2 seconds and then the starter is a non issue. The 7 ran fine for a summer, no issues.
Only issue is when you sit at idle but that is an issue regardless if you have a starter or not.
I suppose a smaller batt might take a bit more abuse but agm batteries should handle it fine.

[shinyribs]

I agree with Rerun.The starter is probably the one thing that works the electrical system the least.It's the highest amperage,but for extremely short durations.I use my kick start just to preserve my starter.Mainly cuz I don't know how to replace it if I had to

[TOOLS1]

I would much rather replace/rebuild the electric starter then the kick starter mechanism.
TOOLS

[MarkPBG]

Would recommend also going to LED's on all the lights with a no load flasher. This will cut your drain a lot, especially at night.

[shinyribs]

TOOLS1 wrote

I would much rather replace/rebuild the electric starter then the kick starter mechanism.
TOOLS

That never even crossed my mind.After i read your post i looked at the FSM.Yeah,i believe i agree with you on that.Thank you Tools,you just gave my leg a break.

[Re-run]

Yes repairing the kicker would truly suck.
I also second the led lights for signals and tail and an HID for the headlight.
I would put in and electronic regulator/rectifier and clean all connections.

[Piute]

                                 
                                 Tech Tip I got from Cycle X
NOTE;
For every un-soldered electrical connection you will lose 1/10 of a volt.
So if your bike has 10 year old points, 30 year old coils and spark caps, nasty wire connections, Fix it!
                                                   

[Blain73]

Piute, I will be replacing the entire wire harness as well as all brand new connections, those that can't be replaced will be cleaned (doubt that will happen).... As to the LED lighting / HID headlight, that is a really good idea and one I had not thought of ( that would be tunnel vision at work )....now for a little back ground on me. I used to work as a electronic instrumentation tech, so wiring harnesses, no problem, spent 10 years as a journeyman machinest, I'm not trying to brag or sound pompous but I am pretty good with my hands. I also want to thank everyone for the great info, input, and ideas, so keep them coming guys, as I am new to to motorcycle restoration / customizing thing, and everyone knows that sometimes all you need are a fresh set of eyes, and that is what you guys are doing for me, plus you never know, might just make a few more friends.