Let’s lean into how batteries manage to keep up with the most prolific developments in motorcycle features of the 21st century: electronics.
Although true of all modern machines, large‑displacement touring motorcycles in particular are laden with digital electronic features virtually unheard of a generation ago. EFI, ABS, and electronic ignition alone nearly double the demands on the battery. Touring bikes add cruise control, audio, GPS, ride modes, heated grips, USB charging, and more – and the list will expand as time goes on.
For decades, if you wanted to run lights and accessories galore, you wanted amp hours. If you wanted to start bigger, beefier engines, you wanted cranking amps. Today, you need both.
Yuasa, for decades the acknowledged master of AGM (absorbent glass mat) technology and OEM supplier for the vast majority of motorcycles, is very aware of this increased demand. It is also in fierce competition for replacement batteries. Over a decade ago, Yuasa cleverly engineered a line of batteries aimed squarely at the modern touring motorcycle and its special requirements. The Yuasa GYZ series is constructed in a unique fashion that improves amp hours and cranking amps, as well as the reliability and durability required for these machines, especially Harleys, Indians, and metric dressers.
Take a peek at the cutaway illustration of the GYZ series battery below. A quick study shows most of what you need to know, but let’s delve deeper into those two critical characteristics that aren’t so obvious.
CCA (cold cranking amps) is the rating of starting ability. The numerical value refers to the number of amps (current) a 12‑volt battery can produce and sustain for 30 seconds at a temperature of 0 degrees Fahrenheit while maintaining at least 7.2 volts. Higher ratings mean better starting of big‑inch and/or high‑compression hot‑rodded engines.
AH (amp hours) is the equally important, if less understood, rating of reserve power. Literally, one amp per hour. In actual usage, a rating of 20 AH with a batch of accessories and equipment that needs 10 amps to function gives two hours of usable power. Change that to 2 amps to operate them, and you get 10 hours. Amp hours are what prop up the charging system’s ability to provide DC power so the engine runs and electronics operate.
Both CCA and AH are where the Yuasa GYZ series really shines. Compared to other AGM batteries, they have 20% more starting power and up to 23% more amp hours. According to Scott Ulrich, marketing and product development manager at Pennsylvania‑based Yuasa Battery, Inc., “stock Harley batteries produce 26 or 28 amp hours with 405 cold cranking amps. Our GYZ32HL battery offers 32 amp hours and 525 cold cranking amps. No other battery comes close.”
As for amp hours, they exceed that of lithium‑ion batteries and offer another useful, if obscure, advantage. If any lithium‑ion battery runs out of juice on the road, the motorcycle will shut off like you hit the kill switch. A Yuasa GYZ, as an advanced AGM battery, warns you to shut off the doodads and head for help. Slow loss of functions, until your engine misfires, becomes a sort of “limp home” mode.
1. Keep It Charged: Depending on type and conditions, batteries may deplete as much as 1% per day. Parasitic drains (EFI computers, security systems, radio memory, clocks, etc.) exist even when the motorcycle is turned off and can discharge a battery in as little as two weeks. Anytime you aren’t riding, connect a smart charger or maintainer of the correct type for your battery. Avoid quick charging! Pro tip: Once a battery drops below 12.4 volts, regardless of recharging success, the life of the battery is shortened.
2. Use Compatible Chargers: Lithium batteries need precise voltage regulation and different charge rates. Even conventional smart chargers may not have evolved enough to be useful on the latest AGM designs, such as the GYZ series for touring bikes. Pro tip: If your charger is more than 5‑7 years old, you’ll benefit from a newer, smarter charger.
3. Avoid Improper Charging and Conditions: Over-, under-, and quick charging harm the chemistry of the battery. Ambient temperature is a major factor as well. Batteries positioned too close to a heat source do not last long or work well. Cold temperatures are just as damaging, if not worse. Optimal temperatures range between 59 and 77 degrees, with a “safe” range of -4 to 140. Charging your battery at anything colder than freezing (32 degrees) is inviting damage. Temperatures higher than 90 degrees encourage sulfation (battery cancer). Pro tip: Using insulated wrapping on the battery is good prevention against both, as long as it is properly ventilated.
4. Clean and Tighten the Terminals: Poor connection is the silent killer of batteries and charging system components. Dirt, moisture, rust, and corrosion can reduce available power by as much as 40%. Disconnect your battery in the off‑season, and check wire conditions and cleanliness when reinstalling at the beginning of the riding season to prevent surprises. Pro tip: Use a wire brush to clean the terminals and then apply a thin coating of dielectric grease on a regular basis. Star washers on snug bolts help maintain good contact.
5. Tie It Down Properly: Motorcycles vibrate at 20‑100 Hz, and if not secured, vibration can destroy battery internals. While not immune, the GYZ series is by far the most resistant. Pro tip: Using common sense and factory mountings is the best protection.
6. Dual Battery Set‑ups: Tourer and cruiser owners have been known to resort to a dual battery arrangement when the factory set‑up proves inadequate for their needs. Pro tip: Do not mix battery types. In parallel, both batteries need to be identical, or the stronger one will try to charge the weaker, killing both prematurely.
Don’t forget: Always wear gloves and safety goggles when handling batteries. Avoid contact with acid or leaking electrolytes. Inspect for cracks or swelling, especially between the body and lid, and ensure the battery mount is secure. Never dispose of a motorcycle battery in the trash. Lead‑acid and lithium batteries must be recycled at designated collection centers.
Always remember – the most amazing thing about electricity is that it works at all!