Batteries

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Batteries - FADM Stern GNSF

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Batteries are probably one of the most misunderstood parts on a bike. A healthy battery is very important, not only for starting and running the bike, but to make sure all the parts in the charging circuitry stay healthy. A bad battery can tax a bikes charging system, causing excessive heat and failure of associated components. While damage may not immediate, the accumulative effects can result in expensive repairs if the already old stator is pushed too hard.

• • Misconceptions

Most people believe that batteries are devices that either work or don’t, but they are a lot more complicated than that. Batteries can become subpar and weak, they can become damaged and defective, and they can cause damage to parts of the charging system. Some of the misconceptions people have are;

• I just bought my battery last year, so it should still be good - Not necessarily true. A battery can be defective right from the day it’s made, or can be damaged during use. The only way to tell if a battery is good (and should be used) is to test it.
• I measured my battery and it’s over 12 Volts so it good - WRONG. A damaged or defective battery can still register 12V or higher when it’s sitting there. This simply means the batteries plates have a potential on them, but DOES NOT mean the battery can deliver the current required.
• My battery was flat, but it charged up OK - This may be true, but as above it does not ensure the battery can deliver the required current.
• I bought a battery 2 years ago and it’s been on the shelf and not used, so it should be fine - WRONG. Even a battery on a shelf will dissipate its stored charge, as the chemical reaction inside takes plate even with no load (reaction takes place MUCH faster when under load). So, a battery sitting there will discharge itself over time, and once it reaches a "terminal phase" in its discharge it will suffer damage and become useless.
• My battery should be good enough; I can charge it after my rides- BAD IDEA. A sub standard battery can draw a large amount of charging current, which puts a large strain on the bikes stator. This can cause excessive heating and breakdown of the insulation on the windings, resulting in a stator failure.

• • Battery 101

The Lead Acid battery is made up of plates, lead, and lead oxide (various other elements are used to change density, hardness, porosity, etc.) with a 35% sulfuric acid and 65% water solution. This solution is called electrolyte, which causes a chemical reaction that produce electrons. When you test a battery with a hydrometer, you are measuring the amount of sulfuric acid in the electrolyte. If your reading is low, that means the chemistry that makes electrons is lacking. So where did the sulfur go? It is resting on the battery plates and when you recharge the battery, the sulfur returns to the electrolyte. So, how does it work?

A battery is a device that creates electric energy from a chemical reaction that takes place inside it (the actions of an acid on metal plates). While the plates and acid are in good condition, the battery will provide a maximum amount of current at the nominal voltage on its plates (2.1V per plate set nom). As the battery is used (discharged), the ability of the battery to supply current goes down, until a point of discharge is reached where it can no longer supply the required current. The electrical energy is created by the "oxidation" of the anode plate, supplying free electrons that are picked up by the cathode which experiences "reduction" that pick up the free electrons. So, in simple terms, electrons are generated and fed to the cathode (- terminal, as electrons flow from negative to positive). During charging (via the bikes generator or a bench charger) the charger forces current into the batteries cathode, which essentially reverses the chemical reaction that produced the power when the battery was used. This is what allows batteries to be used and recharged over and over again.

Now in a perfect world we could do this forever, but in reality all batteries have a limited number of "cycles" they can do before performance degrades. As the batteries chemical reactions take place, the plates and eventually eroded and destroyed, this in a properly maintained battery can take 5-7 years. Also, as the battery becomes discharged and is not charged back up, its plates will become "sulfated" (due to the breakdown of the electrolyte [sulfuric acid]) and unable to process the required reactions fast enough to produce the required current. This is why batteries that have been totally discharged (flattened) and left will not hold a charge anymore.

Now, the important thing about a battery is its ability to supply current (its voltage is secondary and remains fairly constant), which is directly proportional to the plate and electrolyte health. This is why some batteries that seem to charge fine and read 12V will drop to almost zero when a load is placed on them. So, in determining if a battery is any good to use, a load test MUST be performed.

• • Battery state

The state of a battery can be checked by measuring the voltage on it or by checking the specific gravity of the electrolyte. The table below shows the values of both as it relates to the percentage of charge.

State of Charge	Specific Gravity	Voltage
100%	1.265	12.7
*75%	1.225	12.4
50%	1.190	12.2
25%	1.155	12.0
Discharged	1.120	11.9

*Sulfation of Batteries starts when specific gravity falls below 1.225 or voltage measures less than 12.4 for a 12v battery. Sulfation hardens on the battery plates reducing and eventually destroying the ability of the battery to generate power (Volts and Amps).

• • New Batteries

Many small batteries are supplied with the electrolyte in a separate container, or are filled for you when you buy them. If you have to fill a new battery with electrolyte (or just had it filled), you MUST place the battery on a quick charger before using it. The bikes charging system will never bring the battery to a fully charged state and the battery capacity will never be above 80%. Pulling the battery out later and trying to charge it will not work as the battery’s capacity has been permanently cut by 20% and there is nothing you can do about it.

• • Battery types

Basically there are two types of lead acid batteries (along with 3 sub categories); the two main types are Starting (cranking), and Deep Cycle (marine). The starting battery (SLI starting lights ignition) is designed to deliver quick bursts of energy (such as starting engines) and therefore has a greater plate count. The plates are thinner and have somewhat different material composition. The deep cycle battery has less instant energy, but greater long-term energy delivery. Deep cycle batteries have thicker plates and can survive a number of discharge cycles. Starting batteries should not be used for deep cycle applications because the thinner plates are more prone to warping and pitting when discharged. The so-called Dual Purpose Battery is a compromise between the two types of batteries, though it is better to be more specific if possible.

• • Wet Cell (flooded), Gel Cell, and Absorbed Glass Mat (AGM) are various versions of the lead acid battery. The Wet cell comes in two styles; Serviceable and Maintenance free. Both are filled with electrolyte and are basically the same. I prefer one that I can add water to and check the specific gravity of the electrolyte with a hydrometer. The Gel Cell and the AGM batteries are specialty batteries that typically cost twice as much as a premium wet cell. However they store very well and do not tend to sulfate or degrade as easily as wet cell. There is little chance of a hydrogen gas explosion or corrosion when using these batteries; these are the safest lead acid batteries you can use. Gel Cell and some AGM batteries may require a special charging rate. If you don't use or operate your equipment daily, AGM batteries will hold their charge better than other types. If you must depend on top-notch battery performance, spend the extra money. Gel Cell batteries still are being sold but AGM batteries are replacing them in most applications. There is a some common confusion regarding AGM batteries because different manufactures call them by different names; some of the more common names are "sealed regulated valve", "dry cell", "non spillable", and "Valve Regulated Lead Acid" batteries. In most cases AGM batteries will give greater life span and greater cycle life than a wet cell battery.

SPECIAL NOTE about Gel Batteries: It is very common for individuals to use the term GEL CELL when referring to sealed, maintenance free batteries, much like one would use Kleenex when referring to facial tissue or "Xerox machine" when referring to a copy machine. Be very careful when using a battery charger, many times people are using a charger for a Gel Cell battery and in fact the battery is not a Gel Cell.

• • AGM: The Absorbed Glass Matt construction allows the electrolyte to be suspended in close proximity with the plate’s active material. In theory, this enhances both the discharge and recharge efficiency. Common manufacturer applications include high performance engine starting, power sports, deep cycle, solar and storage battery. AGM batteries should be recharged before allowed to drop below the 50% discharge rate. When Deep Cycle AGM batteries are discharged to a rate of no less than 60% the cycle life will be 300 plus cycles.

• • GEL: The Gel Cell is similar to the AGM style because the electrolyte is suspended, but different because technically the AGM battery is still considered to be a wet cell. The electrolyte in a Gel Cell has a silica additive that causes it to set up or stiffen. The recharge voltage on this type of cell is lower than the other styles of lead acid battery. This is probably the most sensitive cell in terms of adverse reactions to over-voltage charging. Gel Batteries are best used in VERY DEEP cycle application and may last a bit longer in hot weather applications. If the incorrect battery charger is used on a Gel Cell battery poor performance and premature failure is certain. Due to the charging circuits on our bikes, Gel Cells should not be used.

• • Battery Value Markings

• • CCA - Cold cranking amps is a measurement of the number of amps a battery can deliver at 0 ° F for 30 seconds and not drop below 7.2 volts. So a high CCA battery rating is especially important in starting battery applications, and in cold weather. This measurement is not particularly important in Deep cycle batteries, though it is the most commonly 'known' battery measurement. For deep cycle batteries without a CCA values listed, the CCA value is roughly 20 X AH.

• • CA - Cranking amps is a measurement of the number of amps a battery can deliver at 32° F for 30 seconds and not drop below 7.2 volts.
  • RC - Reserve Capacity is a very important rating. This is the number of minutes a fully charged battery at 80 ° F will discharge 25 amps until the battery drops below 10.5 volts.
  • AH - Amp hour is a rating usually found on deep cycle batteries. If a battery is rated at 100 amp hours it should deliver 5 amps for 20 hours, 20 amps for 5 hours, etc.

• • Battery life and performance

Two phrases I hear most often are "my battery won't take a charge", and "my battery won't hold a charge". Only 30% of batteries sold today reach the 48-month mark. In fact 80% of all battery failure is related to sulfation build-up. This build up occurs when the sulfur molecules in the electrolyte (battery acid) become so deeply discharged that they begin to coat the battery's lead plates. Before long the plates become so coated that the battery dies. The causes of sulfation are numerous. Let me list some for you.

• Batteries sit too long between charges. As little as 24 hours in hot weather and several days in cooler weather.
• Battery is stored without some type of energy input (smart charger).
• "Deep cycling" an engine starting battery. Remember these batteries can't stand deep discharge.
• Undercharging of a battery to only 90% of capacity will allow sulfation of the battery using the 10% of battery chemistry not reactivated by the incomplete charging cycle.
• Heat of 100 plus F., increases internal discharge. As temperatures increase so does internal discharge. A new fully charged battery left sitting 24 hours a day at 110 degrees F for 30 days would most likely not start an engine.
• Low electrolyte level - battery plates exposed to air will immediately sulfate.
• Incorrect charging levels and settings. Most cheap battery chargers can do more harm than good. See the section on battery charging.
• Cold weather is also hard on the battery. The chemistry does not make the same amount of energy as a warm battery. A deeply discharged battery can freeze solid in sub zero weather.
• Parasitic drain is a load put on a battery with the key off. More info on parasitic drain will follow in this document.

• • Storing Batteries

Batteries will self discharge when stored for long periods of time. This is a normal process with all lead acid batteries. Always charge the battery to full charge before storing. Also disconnect the negative battery cable. This will keep the small system drains from accelerating the discharge process. The best way to avoid shortened battery life is use a smart charger (not a trickle charger) on the battery when it’s not being used. A smart charger is a charging device that will maintain the battery at a full state of charge by testing (load testing) the battery on a regular basis, and charging the battery when the voltage drops to a specified level without overcharging.

• • Battery Charging

Remember you must put back the energy you use immediately. If you don't the battery sulfates and that affects performance and longevity. The alternator is a battery charger. It works well if the battery is not deeply discharged. The alternator tends to overcharge batteries that are very low and the overcharge can damage batteries. In fact an engine starting battery on average has only about 10 deep cycles available when recharged by an alternator. Batteries like to be charged in a certain way, especially when they have been deeply discharged. This type of charging is called 3 step regulated charging. Please note that only special "Smart chargers" using computer technology can perform 3 step charging techniques. You don't find these types of chargers in parts stores and Wal-Marts. The first step is bulk charging where up to 80% of the battery energy capacity is replaced by the charger at the maximum voltage and current amp rating of the charger. When the battery voltage reaches 14.4 volts this begins the absorption charge step. This is where the voltage is held at a constant 14.4 volts and the current (amps) declines until the battery is 98% charged. Next is the Float Step. This is a regulated voltage of not more than 13.4 volts and usually less than 1 amp of current. This in time will bring the battery to 100% charged or close to it. The float charge will not boil or heat batteries but will maintain the batteries at 100% readiness and prevent cycling during long term inactivity. Some Gel Cell and AGM batteries may require special settings or chargers.

• • Discharged Battery

As a battery becomes discharged the percentage of sulfuric acid in the electrolyte becomes less. The sulfuric acid combines with the lead plates producing lead sulfate. As this happens, the electrolyte solution becomes pure water. A discharged battery will freeze in cold climates, which will destroy the insulators and plates inside it. Also, as the electrolyte specific gravity (concentration) drops, "sulfication" of the plate will accelerate, destroying the plates, and making the battery useless.

• • Loose connections

Loose or corroded battery cable lugs can cause all sorts of problems. When the starter is engaged the loose or corroded connection can cause a heavy arc which will melt the post right out of the battery. If the battery is gassing, the arc can cause the battery to explode. Never use the temporary type battery ends. These are only good for emergency use and will become corroded in a short period of time. Always use a crimped and sealed battery cable end or replace the battery cable.

• • Parasitic drain

Is a load put on a battery with the bike is parked (key off). Some bikes have clocks, alarm systems, user accessories, and partial short in the electrical system, etc. The constant low or dead battery caused by excessive parasitic energy drain will dramatically shorten battery life.

• • Battery Testing

Before you can properly test any battery it must be at full charge. You can verify the state of charge with the use of a digital multi-meter. Connect the digital multi-meter to the battery terminals. A fully charged 12 volt battery will read at least 12.6 volts (2.1 volts per cell) on the multi-meter. If your reading is 12.4 or below you must recharge the battery before testing.

• • Battery Load Testing Procedures

Before you can properly test any battery it must be at full charge. The only way you can thoroughly test a battery is to place a high amperage load across the battery terminals. Starter motors have very high amperage requirements which can exceed 300 amps on certain engine applications. If the battery has to be recharged you must first remove the surface charge. This can be done by using the starter. Disable the ignition spark (consult manufacturer’s method to avoid electronic ignition) and crank the engine for 10-15 seconds. Once you have removed the surface charge, disconnect the battery cables and connect the battery load tester to the battery posts. Adjust current draw on the load tester to 50% of the CCA rating. On the batteries in our bikes (14AH rated), the CCA value can be approximately determined to be about 280 CCA, which means a load test would draw about 140 AMPs. Continue this for 15 seconds while viewing the voltage reading on the battery tester. The voltage should stay above the specified reading (see chart below) without falling off. If the voltage remains at the specified level or above, the battery would be considered good. If the voltage reading drops below the specified level, replace the battery.