chopper battery

emzdogz

Aunty Em
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Any reason this battery wouldn't work on an 80, with elec starter? maybe for at least a couple of cranks? I have no prob kicking it but would like to be able to have the starter at least somewhat functional - like if it conked out in traffic or whatever.
http://www.debrix.com/ProductDetails.asp?ProductCode=53-0549-VT

Says 12 volt 6 amp.....

I had my frame purposely made kind of short in the area between engine and back wheel (because I like the look that way) but a stock size battery is going to be hard to fit there, given that I have mid-controls and a brake master cylinder that need to go in that area too.

thanks in advance,
:)
 
I don't know if it would work or not.. It's doesn't say the cold cranking amps anywhere in the ad that I can see. Even if it did, I don't know how low you could go and still have the electric start work. :shrug:
 
- i dont think its going to be enough, an original alternator, ignition and e-start are all going to require power to start your bike, assuming youve got all your lights and indicators turned off you will still need around 140A starting power
 
Well, the factor is 20. A 14 AH battery will provide 280 CCA (Cold Cranking Amps) for 30 seconds. The starter motor on the XS650 develops about .5 KW or 500 Watts. At a nominal 12 volts, that's about 42 Amps, so a standard 14AH battery should be good for 280/42 = 6.6 cycles for 30 sec each, or about 3.3 minutes of cranking before the battery voltage drops to 8 Volts.

A 6AH battery would have a CCA rating of about 120, so it would be good for 120/42 = 2.8 cycles or about 1.4 minutes of cranking before the voltage dropped to 8 or less.

All of these guesses are based on the CCA standard of zero degrees temperature, so you would do a little better at room temperature. However, both the TCI and points ignition do not work very well at low battery voltage, so you will have a problem if the battery gets below about 9 volts. A PAMCO ignition will work all the way down to 6 volts and is used successfully in no battery setups, so it would be a good candidate for a 6AH battery setup.

Note: above guesses based on a brand new, fully charged battery operating a starter motor with good brushes.
 
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thanks Pete. So what I take from what you wrote is that it would work, but not for cranking over and over?
 
emzdogz,

Right. You could help the process by following a starting routine:

1. Prime the engine when cold with the kick starter. (ignition off, choke on)
2. Hold the clutch in and kick until the clutch breaks loose.
3. Continue holding the clutch in when you operate the starter with the ignition on.
4. Operate the starter for no more than 15 seconds at a time.
 
- i still dont think its big enough...starter 500W, ign ca 40W, alternator ca 25W...makes about 600W draw before you start if you include the switching
- you will need a top battery, in full charge, all other electrics turned off, top condition starter-which are notoriously weak to start with, top condition alternator, wiring in great condition too...any shortcomings in the system will very quickly show themselves :twocents:
 
If you want a small battery use the kick start and junk the electric, unless you have a particularly good electric starter they are so noisy they are embaressing. I've only had a couple that have worked properly.
 
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