Battery Maintenance & Safety

By Yuasa Inc.

SULFATION AND FREEZING

Two of the biggest battery killers - sulfation and freezing - aren't a problem if the battery is properly maintained and water level is kept where it should be.

Sulfation

This happens because of 1) continuous discharging, or 2) low electrolyte levels.

Let's back up just a minute: we said earlier that discharge turns the lead plates into lead sulfate. This lead sulfate is actually a crystal. If the discharge continues uninterrupted, the sulfate crystals grow and blossom into sulfation - and a problem.

Much the same happens if the fluid level is too low, which exposes the plates to air. Then the active lead material oxidizes and sulfates, and it doesn't take long before it won't hold a charge. (Low electrolyte levels cause another problem, too: acid in the electrolyte becomes more concentrated, causing material to corrode and fall to the bottom. In sufficient quantity, it will short out the battery.)

Keeping a battery charged, pulling the battery cable during storage, and keeping electrolyte levels up eliminate the problem. For added protection, YUASA"s YuMicron, YuMicron CX and GRT batteries are treated with a special chemical formula called "Sulfate Stop." This dramatically reduces sulfate crystal buildup on plates. The result: longer battery life.

How good is Sulfate Stop?

We simulated a constant discharge condition on two batteries with a 10-watt bulb. Even after being totally drained for a week, the battery with Sulfate Stop made a 90% recovery.

The untreated battery: useless.

Freezing

It shouldn't bother you - unless a battery is inadequately charged. Looking one more time at the discharge process, remember that electrolyte acid becomes water as discharge occurs. Now, it takes Arctic temperatures to freeze acid. But water...as we all know, freezing starts at 32° F. A sign of this is mossing - little red lines on the plates - but it's tough to see unless you've got great eyes. Freezing can also crack the case and buckle the plates, which means the battery is shot.

A fully charged battery can be stored at sub-freezing temperatures with no damage. As the chart shows, it takes - 75° F to freeze electrolyte in a charged battery. But as just a couple degrees below freezing, at +27° F, a discharged battery's electrolyte turns to ice. That's a difference of more than 100° F between the low temperatures a charged and discharged battery can stand.

At temperatures such as these, incidentally, the self-discharge rate of a battery is so low that a recharge usually isn't needed for months. But to stay on the safe side, test.

Electrolyte Freezing Points

CHARGING A NEW BATTERY

The MOST IMPORTANT thing to remember about charging a new battery is to actually do it!

How many times have you seen somebody ready to throw a new battery into a bike and ride off - without charging? "The bike will charge it," they figure.

Wrong. The battery will be damaged for life.

A battery out of the box, with the electrolyte added but uncharged, is at 80% capacity tops. If it's installed and used that way - without an initial booster charge first - it'll never hold more than that 80% charge. The bike won't charge it higher. Neither will pulling the battery off later and trying to charge it to full capacity. The battery's capacity has been immediately and permanently cut by 20%, and there's nothing you can do about it. Insist on that booster charge.

The rule of thumb is to charge a new battery for three to five hours at a rate equal to 1/10 of its rated capacity. But there are a lot of exceptions to that rule, as this table shows:

Hours to Charge Battery 100%*

*These figures are based on using a trickle or taper charger.

If you're careful about monitoring and you're using a digital voltmeter (or multimeter), it's possible to bring that new battery to more than a full charge. This is what you do: periodically pull the battery off the charger and give it time to stabilize. Then check the voltage. The voltage will continue to climb - for YUASA batteries, up to 16v or 17v - and then will start to drop. When it does that, you've reached max.

Quick Charges

What about quick charging? The quick answer is: don't. We don't recommend it, and here's why: only the surface area of the battery plates can be quick charged. A lower current charges the battery more uniformly. That means better performance. Also, charging rates above 2 or 2.5 amperes increase the chance of overheating, which can mean battery damage.

AVAILABLE TYPES OF CHARGERS

There are five basic types of battery chargers. With all of them, hook the positive charger lead to the positve battery terminal, and the negative to the negative. Some chargers on the market deliver a low charging voltage that can't fully charge the battery; avoid them if you're buying a charger. A 12 volt, 1 amp. charger will meet most needs.

Of course, too much of a charge can be a problem, too - it can "cook" a battery. For small engine starting batteries, don't use a charge greater than 2 to 2.5 amps for maintenance purposes. A badly discharged battery with very high internal resistance may never accept a charge from a standard charger. It would then require special charging equipment.

ALWAYS OBSERVE PROPER SAFETY PRECAUTIONS WHEN CHARGING BATTERIES!

Trickle Charger: 

This is the charger a consumer - as opposed to a battery retailer or garage - will usually have. It charges the battery at a fixed rate. Different ampere-hour batteries have different charge rates. For most motorcycle and other small engine starting batteries, charge them at 1/10 of the rated ampere-hour values.

Battery voltage increases with the amount of charge. Charging voltage should not exceed 14v to 15v for lead-antimony batteries, or 15v to 16v for maintenance free, low maintenance and sealed types.

Find charging time for a completely discharged battery by multiplying the ampere-hour rating by 1.3.

Test the battery during charging, and continue charging until all cells are gassing. Use either a voltmeter (or multimeter) or hydrometer. The specific gravity of the electrolyte in all cells in a fully-charged battery should come to at least 1.265 in a conventional battery and 1.280 in a YuMicron battery with Sulfate Stop.

During charging, check the electrolyte level periodically and add water - preferably distilled - to keep the electrolyte level up to the line. If the battery becomes hot to the touch, stop charging, Resume after it has cooled.

Note that permanently sealed batteries - Yuasa's Maintenance-Free battery, for example - generally can be tested only with a voltmeter or multimeter. These batteries are fully charged when the voltage peaks and then begins to fall - as high as 17v, for example, on the Maintenance-Free battery.

Do not hook a battery to a trickle charger and leave it unchecked for longer than overnight. After about eight hours maximum, careful monitoring is required. Caps need to be replaced tightly after charging's done.

Taper charger:

Similar to the trickle charger, the taper charger charges at a fixed voltage. As the battery's voltage increases with the amount of charge, the current drops accordingly.

A drawback of both the taper and trickle chargers is speed...they don't have it. It can take days to bring a discharged battery up to 100%. Here, too, check batteries for overheating as they charge.

Constant Current Charger:

A professional-quality charger, the constant-current makes charging simple. It maintains a constant supply of current to the battery at all levels of charging. You select the charging current. As the battery voltage increases with the amount of charge, this charger automatically increases the charging voltage to maintain the current output.

Pulse Charger:

This is the state of the art in charger technology. The pulse charger monitors the voltage constantly during charging and standby modes.

When battery voltage reaches a specified low level, the pulse charger then delivers a full battery charge. Then when the battery gets to the specified high voltage, it automatically drops the charge.

High Rate Charger:

Not to for use with small engine starting batteries. They force a high current into the battery, which can lead to overheating and plate damage.

Battery Voltage

Specific Gravity