The coolest bikes have always been the stripped down. Whether stock or custom, the less crap the better. So long as the engines weren't too big, or you were running a kick-starter, you could get through life on a stock battery or with a magneto. Without turn signals, horns, and other odds and ends to eat away battery life, firing up a custom bike with a couple kicks or the push of a button was never a problem.
That was cool until the late '90s when everybody started boring and stroking engines past the 100-inch mark. What used to be a gigantic monster motor quickly became the norm within a couple of years. Stock starters could no longer cut it when it came time to crank one of these beasts over. Kick starting a 131 that's already warmed up to operating temperature is no easy chore either, making an electric starter even more of a necessity. Making things even worse is the fact that rear tires are getting bigger and frames are getting smaller, leaving very little room for a large enough battery to fire larger high-compression engines.
You can only do so much with the small battery box custom frame builders are designing into their low-seat frames. You can either pick a smaller engine or possibly install compression releases. Besides that, something like Compu-Fireís new Direct Drive starter system would be the ideal, but much more costly solution. There is really only so much that can be done when waving big inches in front of a small box.
Big Boar Products has been a great source for potent replacement batteries for Harleys and customs for many years. It's 10-plus years of building frames has also taught Big Boar a great deal about the importance of balancing aesthetics, while leaving just enough room for a few necessities. Important stuff like having enough room for a decent size battery is drawn into the plans of all Big Boar frames from the start.
“It's just common sense,” states Aaron Dills, president of Big Boar Products.
Dills tells us that he's begged and pleaded with some of the biggest frame builders in the business, many of which are his good friends, to leave enough space to allow for a battery strong enough to crank over a high-compression 120-inch-plus engine.
Dills says, “They always have some reason, like the customer wants a bigger tire, or the trans sticks back too far, or the seat's too low.”
“A high-compression V-twin engine can take more battery power to crank over than a big-block Chevrolet engine,” says Dills. “Think about it, the flywheel on a car is huge, and the gear on the starter is very small, giving you a decent ratio to turn things over without a lot of battery power.”
“On an American V-twin motorcycle engine, you have a starter with a drive gear that's almost the same size as one on a car starter, but the ring gear it turns around the clutch isn't much bigger than an over-sized softball. Then, to make the loss of the leverage from using a smaller ring gear even worse, the primary chain on a Harley gears it down as the starting power is passed on to the crank! It's all backwards!” exclaims Dills with a huge smile.
That would provide enough room for one of Big Boar's BB350 batteries with 350 Cold Cranking Amps. Cold Cranking Amps, or CCA, are usually measured at freezing temperatures, and fortunately, the output of the battery is much higher at temperatures that people actually ride in.
Many frames only leave enough room for Big Boar's Mini 300 battery that contains 200 Cold Cranking Amps in a 6-inch-long, 3-1/2-inch-wide, by 5-1/4-inch-tall package.
“Our Mini 300 will turn-over 100-inch RevTechs all day long, but I wouldn't want to push it beyond that.” A typical aftermarket high-torque starter can easily pull about 300 amps, and some high-performance applications can make a starter draw nearly 500 amps under severe conditions.
What's the bottom line? Well, until the laws of physics can be warped to suit our needs, you can only fit so much battery into a tiny package and still be able to turn over an engine and fire the ignition. While battery size and weight ratios have peaked with current technology, engine sizes have continued to grow and there is no decline, or even a leveling off, in sight. Use the largest battery that you can get away with and install compression releases if that won't work. What? You didn't think there was going to be some sort of magic answer at the end of the rainbow did you?
1. Always fully charge any battery before putting it into service. Big Boar batteries are fully charged before being sold, but any battery sitting idle can loose 1/10 volt per day. Putting a battery into service without an adequate initial charge can shorten the overall life of a battery.
2. Never use a charger larger than 10 amps on any motorcycle battery, and even then for only a few minutes at most for a quick boost. Only chargers of 2 amps or less should be used on a motorcycle battery for any length of time to avoid boiling it over and burning it up.
Big Boar recommends the Deltran Battery Tender, or similar-type chargers, to keep your batteries safely in peak shape.
3. Install batteries in their intended position and make sure that vent tubes, if so equipped, are properly run. If a battery that isnít made to be installed on its side leaks acid, your bike will surely be damaged and you most likely will have a dead battery (just to rub your nose in it). A vent tube that vents in front of the wheel can leak acid that will destroy chrome, paint, and anything else that stands in its path as the wheel flings the droplets about.
4. Check below seat pans, especially metal ones, for contact with the top of the battery terminals. Dills has witnessed more than a few fires started by batteries shorted out by a low-hanging seat pan.
5. Always ground the starter motor directly and use heavy-gauge cable. Some stock bike starters are grounded in a roundabout way through the frame. Making the power run the shortest route possible from the battery to the starter prevents energy lost through heat. Dills also recommends the use of cable no smaller than #4, stating that the #6-gauge typically used by the factory is too small (see Sumax or Terry Component cables).
6. Test a questionable battery with a load tester. What looks good on a cheap volt meter after a long charging session may leave you stranded with no way home. A good load tester mimics the instant real-world strain inflicted upon a battery after cranking over your engine for a few seconds for a more accurate test than checking for voltage alone.
7. If you have a big motor and a small battery, make sure you ride your bike long enough after each start to replenish the battery between starts. This can mean as much as 50 miles of riding in some cases. Get to know your bike and its charging characteristics before heading out for a long trip.
8. Unhook your battery if you plan on storing your bike for more than a month at a time. Some bikes have memory chips on board that sap a few millivolts from your battery, even though the ignition switch may be off. Once a battery is allowed to completely discharge and remain there for any length of time, it can be impossible to revive the battery by charging it.
9. Use only baking soda and water to clean top of battery and terminals. Some degreasing agents and aerosol cleaners can mix with battery acid and destroy paint or eat rubber and plastic items.
10. Don't try to start your bike with a battery charger unless the charger has a high-amp boost setting. Using a charger of 10 amps or less in an attempt to fire up your bike can damage or destroy it. A battery charger is only supposed to restore power to a battery slowly after it is lost and cannot supply the high instantaneous amount of current required to start an engine.
SOURCE
Big Boar Products
www.bigboarproducts.com
