Batteries

Before you start any electrical diagnosis it is imperative that you have a" known"good battery that is fully 100 % charged. Anything less and you are just spinning your wheels trying to make sence of faulty data, especially when trying to diagnois starter problems. What i mean by " known" is all cells are functioning normal. On non maintenance free batteries make sure the water level is correct and you have no milky cells. If there are no water level marks make sure that the water covers the plates and is about 1/4" from the top. If you have to add water use only distilled water but in extreme circumstances use bottled or tap water. Make sure the vent tube is not pinched or bent and is allowed to drain into a non metalic container, bowl, cup ,glass ect. and upon installation on your make sure the vent tube is long enough to hang a couple of inches below the frame, battery gasses are ***** to chrome and alluminum. Charge battery to a 100% full capacity state and let it sit for a 24 hours. Then do a hydrometer test. A fully charged cell will read 1.270 to 1.280 at 80 degrees fahrenheit temp. For every 10 degrees above 80 add 4 points to the reading for every 10 degrees below 80 subract 4 points. If the numbers between the highest cell reading and the lowest cell reading is more than 50 points replace the battery. Now if you have a maintenance free battery where there is no cell access the battery must be charged to full 100% capacity 12.8 volts, and after reaching this mark let it sit for 2 hours then check it with a load tester. If you do not have one or acess to one you may take the battery to any automotive or bike shop and they will usually do it on the spot for free, in which case a couple of bucks of gratitude would be in order. Some places may charge a small nominal fee which is the same as a tip. Voltage should not drop below 9.6 volts. Major electrical ignition components need at least 9 volts to function properly. These are borderline minimum specs. Anything in the 8's or lower replace the battery. A motor cycle battery charger is the best way to charge your battery usually has a low amp rate 1 to 2 amps and takes 24 hrs to ensure a full charge. If you have to use an automotive charger make sure it has tapering capbilities and is set at its lowest rate. If any battery becomes hot to the touch 110 degres or higher charging must stop immeadiately and after the battery is cooled down to room temperature then use a lower rate charger. Usually old batteries that heat up quickly are starting to fail and should be relaced. A hot battery can warp plates causing permanent damage. How long should a battery last? it all depends on maintenance and abuse. I have seen new batteries fail in just a few weeks and i have personally serviced an FLH battery that was over 7 years old. The best way you can extend the life of any new battery is to give it nice slow overnite charge before you ever install it on the bike. A new battery may read 12 volts or higher but you never know how long it was sitting on the shelf and may only have a 75% charge. This capacity will still probably start the bike but once that starter button is hit for the very first time the battery plates will set to that 75% charge capacity and 99% of the time that battery will never take more than a 75% capacity charge and battery life and performance will suffer immensely so always start with fully 100% charged new battery before you hit that starter button. It will add years to battery life. Also make sure your battery conections are good and tight, a thin layer of grease on the terminals and bolts will protect the terminals from corrosion, and most important on any battery instalation is to make sure that the positve terminal and or bolt is not so close to any metal part that you cannot force it with your hand to touch. Secured batteries are a must and those of you with aftermarket custom seats must pay special attention to battery contact. A nice thick layer of automotive innertube or battery tray ruuber cushion on top of the battery will prevent potential disater. Do what ever it takes to insulate that posive terminal. There is a reason why charged batteries are never stored on a concrete floor, that same reason aplies to terminals that in very close proximity to metal base custom seats. I hope all this helps you guys who are pulling you hair out trying to solve a simple electrical issue, and my sympathies go out to those brave souls that spent tons of money throwing parts on their bike to solve a charging issue and or starter issue. This is not rocket science although to some it may seem so, its basic math and just about numbers. I would like to close with a phrase I heard a long time ago that totaly captures the essence of this tutorial,
"garbage in garbage out " Good luck gentlemen and may the Harley Gods be with you.