Next installment is about batteries. We take batteries for granted, and generally abuse batteries. I believe this to be primarily because batteries for our bikes or even our vehicles are relatively inexpensive. I lived on a 40 foot boat where the battery replacement cost was upwards of $3,000.00 for the Lifeline AGM 8D batteries. On to the subject at hand.Batteries
Batteries are generally the first item that gets renewed when a person purchases an older GW, or replaced due to age. We all expect/hope that the components in the electrical system will work well beyond the life expectancy of the battery.
Batteries have a calendar life, shelf life and cycle life.
Calendar life is that where the elapsed time before a battery becomes unusable whether it is in active or inactive use. Key factors that influence calendar life are temperature and time.
Shelf life is similar to calendar life in that it is the time a battery can be stored before use. Shelf life is generally said to expire when an inactive battery has been stored and has reached a state of charge of 80 percent.
Cycle life depends on the type of battery. This is defined as the number of complete charge - discharge cycles a battery can perform before the battery state of charge that can be maintained falls below 80 percent of the initial rated state of charge.
There is a considerable amount of information regarding the life expectancy of batteries and how each element affects a battery that you may be considering buying. I mentioning the above three life aspects of batteries so that you will consider asking a few questions regarding your battery purchase such as date of manufacture, how has the battery been stored, and such.
Batteries that are available for our bikes are of the lead acid type; flooded cell, AGM, and Gel. The newest battery on the market is a lithium battery. There are pros and cons for each, and availability of the older technology such as a flooded cell lead acid battery for a motorcycle may be difficult to source if one were inclined to use this type. The newer batteries are a considerable improvement over the lead acid battery, but each has benefits and some draw backs as well.
The state of charge for all lead acid batteries is generally the same. It may vary depending on the state of charge, or the type of lead acid battery; however, these lead acid batteries all discharge at approximately the same rate depending on age of the battery, and temperature.
A standard state of charge chart is:
Figure 1 – Battery State of Charge Chart
Motorcycle batteries are storage batteries, store electrical power which is generated by the bike's charging system, which in turn is powered by the engine.
Batteries designed and installed on our bikes are designed to provide power for the starter, load levelling - voltage spike absorption, and supplemental power when the charging system is not producing sufficient output to the electrical system. This is the accepted use of a battery in a vehicle electrical system. The wiring to provide a charge to the battery is sufficient for this task, but may not be adequately sized for additional loads to draw power from. It is also sized for short duration charging of a 100% state of charge battery.
It is generally accepted that a battery in good condition will probably be discharged approximately 3% of the battery charge at time of use. This discharge percentage will invariably change depending on the state of charge at time of use. I would submit that the amount of discharge will increase, probably exponentially, as the state of charge is less at time of starting the bike. This 3% discharge is easily and readily topped up by the charging system soon after the bike is started.
Another accepted norm for this type of battery is that it can withstand approximately 10 deep cycle discharges before it needs to be replaced. I think this is based on a car battery, and that because the size of a motorcycle battery is considerably smaller, a motorcycle battery may not meet a 10 deep cycle discharge parameter.
From my research, I have found that it is never a good idea to re-charge a low battery, or dead battery as we know it with the alternator. The high current and voltage requirements can be hard on the charging system components, and electrical system wiring and components. A battery that has been drained, can require a significant amount of power to come up to a 100% state of charge, and in doing so the voltage in the electrical system can be greater than the requisite design voltage of approximately 14.2 VDC. This could result in electrical system components being damaged as well and cause premature battery failure. A battery that has been drained sufficiently to require a boost, or is at a low state of charge should be charged by an industrial, workshop type charger. The alternator purpose is to operate the vehicle electrical system, provide the battery with a quick charge after staring the bike, and keep the battery topped up for future use. Lead Acid Battery
The lead acid batteries, flooded, absorbent glass mat (AGM), and Gel all do the same job. The flooded lead acid battery is a mainstay in several applications, but have been surpassed in the motorcycle industry by the AGM and Gel batteries. A newcomer to the motorcycle market is the lithium battery.
Flooded, wet cell lead acid batteries contain liquid electrolyte and are lowest in initial cost. They’re usually not sealed, so the water in the electrolyte that’s lost while charging the battery can be replenished. Failure to replace the water can damage, or ruin the battery and is one of the most common reasons wet-cell batteries fail. Wet cell batteries are the most fragile type, and the acid can do extensive damage if it leaks out.
Wet cell batteries require regular, periodic checks of electrolyte levels. In hot weather and following extended high-speed use, they may need to be topped off every few days or weeks. With the battery positioned level, the height of the electrolyte must at least cover the top of the plates inside, and should be maintained at or near the full marks. Distilled water should be used to replace the water than has been lost. It's not a good idea to use regular tap water because it contaminates the battery with unwanted minerals, shortening its service life. When removing caps, be careful not to splash the acid-bearing electrolyte, which can destroy clothing, paint and cause severe burns, and even blindness if it gets in the eyes.
Protective gear is highly recommended when working with wet cell batteries such as wearing rubber gloves and eye protection. Wet cells can be checked for charge level with a hydrometer. A 100-percent charge yields 1.265 specific gravity, 1.225 is 75-percent charge, 1.190 is 50-percent, 1.155 is 25-percent and 1.120 is discharged.
Wet cell batteries are the most maintenance intensive of all the batteries available for use in motorcycles. These batteries can also be the most problematic because they are not sealed units.
Gel cell batteries are sealed units, and use thick electrolyte fluid so they do not spill if they tip over. The Gel cell battery is a valve-regulated lead-acid battery (VRLA battery) sometimes called sealed lead-acid (SLA – AGM batteries are classified as such as well), Gel cell, or maintenance free battery. The sulphuric acid is mixed with fumed silica to make a gel like mass that allows the installation of this battery in various orientations, not necessarily upright. This gel like mass reduces electrolyte evaporation, spillage, and has greater resistance to to shock and vibration.
Both the wet and Gel cell batteries have lead plates inside but the thicker gel holds up to the rigours of riding quite a bit better and the special vents only allow gas to escape if it is overcharged so there's almost no risk of getting any fluid on you or your bike. The introduction of the Gel battery was the next step in the evolution of power sport battery technology but it has quickly been surpassed by the AGM type. Gel batteries generally require lower charging voltage, so you will need to adjust the charging equipment accordingly. Check the rating on the side of your specific battery, before you hook it up to the charger.
AGM, also a VRLA battery, uses a fibreglass-type glass mat separator to hold the electrolyte in place. AGMs are spill-proof and the most vibration-resistant lead batteries available. AGMs typically last longer than wet or gel cell batteries, offsetting their extra cost. AGMs batteries use almost the same voltage set-points as wet cells and thus can be used as drop-in replacements for them. Both Gel and AGM batteries can deliver power at about a 25-percent higher rate than flooded cells. However, since they are also sealed and are valve-regulated lead acid battery, charging has to be controlled or they too can be damaged.
Gel and AGM batteries require no maintenance as long as the charging system is properly set up, and an appropriate battery charger for a VRLA battery is used. They have no electrolyte to replenish, and never require specific gravity checks.
Advantages of AGM and Gel VRLA batteries:
1. Have shorter recharge times than flooded lead acid batteries;
2. Discharge significantly less hydrogen gas;
3. Safer for the environment; and
4. Can be used or positioned in any orientation.
Disadvantages of AGM and Gel VRLA batteries:
1. Cannot tolerate overcharging, overcharging of these batteries results in premature failure; and
2. Have shorter, useful life than properly maintained wet cell batteries.
The one aspect of all lead acid batteries is thee requirement for long charge times that should consist of a bulk and float charge. Lead acid batteries will accept a bulk charge up to 70% rather quickly, and require a float charge for the remaining 30% for an extended period of time, up to 10 hours depending. To ensure longevity of a lead acid battery, it should be kept at full charge when stored, and when being used depth of discharge should not exceed 20%. These are accepted norms and provided as information. If you, the reader require additional information, there is a plethora of information awaiting for your perusal be it the internet or like sources.Lithium Battery
Lithium batteries are the latest newcomer to be used in motorcycles. Lithium batteries are not to be confused with a lithium ion battery.
Lithium batteries, sometimes called lithium-metal batteries, have a high charge density (long life) and high cost per unit. Charge density is basically the amount of electric charge per unit length, surface area, or volume. There are other variables, but these are the primary ones.
There are many reasons for an upgrade to the lithium battery, but an understanding of the limitations and what you as a user of this type of battery should know is paramount in enjoying the benefits of a lithium battery. For myself, I will continue to use an AGM battery as there are other aspects of riding and maintaining my bike that require my attention, more so than the battery.
Advantages of lithium batteries:
1. Lithium batteries have a higher energy density, so they can have a higher output at a lighter weight. They are usually about a third of the weight of the standard lead acid battery supplied as original equipment in almost every motorcycle;
2. These batteries have a longer shelf life when not in use. Many batteries we buy have already been sitting on the shelf for some time so we are only getting a portion of their maximum capacity;
3. Motorcycle batteries are constantly being recharged, which reduces their life. Lithium batteries are able to be recharged a far larger number of times. So they cost more than a lead acid battery, but will last much longer;
4. If it does run flat, it can be recharged very quickly, but needs a special charger or a simple charger without desulphation modes;
5. Lithium batteries have a lower internal self discharge rate to lead acid batteries so they do not need to be tendered in winter or periods of disuse in the manner lead acid batteries do. Typically, a lithium battery can be left unused for up to six months without charging, whereas a lead acid battery would need the battery charged far sooner;
6. A lithium battery may start your bike quicker because lithium is a lower impedance internally which allows delivery of up to 90% of the stored energy in one hit. Lead acid batteries typically can only deliver around 1/3 of the stored energy in one go. Hence the Lithium batteries have higher CCA ratings (Cold Cranking Amps);
7. If you are customizing your bike and want to create a void where the battery usually lives, use a lithium battery. They are much smaller and can be located anywhere and at any angle; and
8. You should purchase the largest-capacity Lithium battery you can.
Lithium Battery Disadvantages
1. Be careful not to overcharge lithium batteries as they can overheat. Make sure you charge them with a suitable, lithium battery charger; and
2. Lithium batteries are susceptible to extremes of cold or heat. Understanding how cold and heat affect a lithium battery is required but discussion items for another topic.
I have included a short mention on the varying battery types available as a preamble into the world of batteries and the rest of this section. The above information has been gleaned off the internet web sites and it is recommended to do additional research to ensure you get the right battery for your application. Most of the following information that I have come to understand is primarily related to lead acid batteries and not the newest technology available, that of the lithium battery.