I am just getting back into riding after several years off. If I only ride my fatboy on the weekends, do I need to keep it on the trickle charger during the week? Any advice would be appreciated. Thank you

 

A lot more then you need but my point on there use..

Rev. 03-29-17
Some electrical 101 and a little more..

Remember, the best made brand new battery that has been on a maintenance charger for 3 days that has a loose or bad connection is no better then a boat anchor with a loose rope. The connection can get loose after one ride if the battery is not anchored and the wires are short and get tugged in a direction that can unscrew the bolts.

After a good 24+ hour maintenance low amperage (never over 2 amp) charge, with the charge light in the solid green and the battery has set about 24 hours off charge, voltage should be about 12.8 volts.
You can speed up this process by turning on the ignition key (headlight comes on) for ~3 seconds and then switch it back off. This is enough of a load to bleed off the excess residual charge from the charger and then you can measure the battery voltage.

12.8 = fully charged
12.6 = 75% charged
12.3 = 50% charged (Lot of new modern cars with system protection will not even click at this point but will have good headlight beams showing)
12.0 =25% charged

Always check both the terminals at the battery lead and also at the terminal on the wire. That helps to verify connection. With a DC volt meter (one that has a feature to lock high and low reading is best) hooked across the battery terminals and reading 12.8 or so, crank motor and while its cranking it should not drop below about 9.6 volts and as soon as it starts and throttled up to 2000 rpm, voltage should read around 14.8 volts. The 2000 rpm is the bench mark standard. Ignore idle output. Ignore output above 2000rpm unless it exceeds 14.9 volts. That is a sure indication that regulator is bad.

The crank check shows a rough check of the reserve amperage capacity of the battery while cranking with a 150-200 amp load on it. The 14.8 shows a good alternator and if you leave it on a while as the regulatory will drop the voltage a little showing itself working. However, with the lights and stuff always on, it will never drop back much. If you have a lot of options, most modern bikes will not show 14.8 charging volts at idle but stock newer bikes will be close. Older bikes with lower amperage output not so much. However, 2000 rpm is the bench mark for the standard 14.8 volts.

If you think battery is good and something is draining it sitting, now would be a good time to check for drain problems. Go to Harbor Freight and get you a AC/DC meter for under $25 or so. http://www.harborfreight.com/ac-dc-d...ter-37772.html Make sure it has DC amps draw, DC voltage, resistance and AC voltage. Key off. Remove the negative cable off the battery. Set meter on DC amps. Hook the meter lead to cable and the other to battery. !!Key off.do not turn on!! Ignore that first draw as the alarm trims back and stuff charges for 1 minute. Now, how many milliamps (mA) is it drawing? It should be no more then 6 mA which is the ECM (1), speedometer (1), tac, TSSM (1), HFSM (1) and voltage regulator (1)

When a battery wears out, a good charge will show fairly good voltage, but the battery can still have very low amperage capacity which will show in the crude crank test above, but it really should be checked after a good charge by removing it from bike and getting a free check at a place like AutoZone that has a fancy load meter check that gives you a print out of the battery health. Battery MUST BE CHARGED to check it. Be sure they set their meter to correct cold cranking amperage stated on the battery. Never charge the AGM absorbed glass mat battery with a regular car battery charger unless it is a newer one that says safe with this type of battery. Also, by taking battery out you now know you have good connections. Vibration tends to loosen the connections or a little corrosion will prevent charging or cause starting problems. Be forwarned, these checks quite often are incorrect due to the low amperage of these small batteries and junk checking equipment. If bike is charging, no load on battery when key is off and you are still having problems…REPLACE THE BATTERY. If battery is more then 3-4 years old.. REPLACE THE BATTERY.

Using the maintenance charger can get more years from a battery but be careful here. You do not want the last start 5 miles from home. If it still grunts when you first hit starter or kicks back with a bang, replace it. After a few years, charge and pull battery and have it checked for cold cranking amperage ever spring. Even then, if it grunts most ever start, I would replace it. Most battery checkers at AutoZone and places like that do not do really well on the low amperage setting on small batteries. Not sure why but they tend to say they are OK when they are weak. If they have one that fits your bike, Wal-Mart's AGM absorbed glass mat battery is just as good as any for one third to half the money of a Harley Battery. My last 4 years befor it started grunting. And out it came. Do not put an old fashion one with vent tubes on a modern TC Harley. Do not jump, push start or run bike with a half dead battery except in a real emergency. If a bike battery is down and you jump it, throwing all that amps to it from a big car battery especially one that is running can wreck a bike regulator or charging system. Charging a worn out battery can kill alternator stator or the voltage regulator or both. Probably ending in a big dollar repair in parts alone.

It is also a good idea to always check your battery at 2000 RPM with your meter set to AC. If by chance, the regulator goes bad, sometimes it will let AC come thru. That is a sure sign of a bad regulator. Older 2 wire stators have a single-phase output while the newer stators with 3 wires have a 3 phase output. The 3 phase system provides a more consistent and higher current output to the voltage regulator. The voltage regulator takes the AC from the alternator, rectifies it to DC and limits the voltage level to the battery depending on the voltage reading it gets back from the battery.

Also remember, when starting a Harley, hit the starter and hold it in till it is firing on both cylinders and running before letting up. If you let up before it’s running, quiet often, it actually take an FI motor longer to start. There is a fraction of a second more for a long stroke Harley then a multi-cylinder car for it to get going. If you do not do this, it will kick back with a bang, sneeze thru the intake or crank a lot longer the second time or shame on you the third time. Also, if you have a habit of doing this, the starter solenoid switch contact will only have half the life it could. You cannot hurt the starter. The starter gear has a sprag clutch. There are drive pins in it that as the gas motor catches and run, it outruns the starter motor drive and disengages it from the electric motor. If you hold it in a little too long and listen carefully, you will hear the sprag clutch run up the ramps and slip. Makes a sizzle hum. This will show you your starter sprag clutch is OK.

My batteries:
11-05-03 Originial Harley 3 years
08-07-06 Harley 6.5 years (nursed way too long and was grunting and banging often)
04-29-13 Walmart Ever Start 4 years (grunting)
03-25-17 AutoZone Duralast Gold

 

I keep mine on a battery tender. As soon as I park it, I put it on the tender.

 

all my bikes go on a tender once a month if not ridden

 

Based on a very old technical product review I once read, these 5 phase chargers were the best of the best:

https://fortnine.ca/en/yuasa-smartsh...attery-charger

The catch is; Yuasa doesn't make em any more but a few places, like this Canadian site (excellent service BTW), has em. This is Canadian pricing so the deal is probably a great one even if you're having it shipped to the States.

I have 3 of these and have left my Breakout on one continuously for as long as 9 months while I was overseas at work. The tender does precisely what it should.

Noteworthy; Yuasa's primary business, and reputation, is from making the batteries these tenders are designed to protect. FWIW.

 

Battery Tender Jr. Mine are 10 years old and still doing their jobs. I just picked a new style BTJ off eBay for $21 shipped. It is much lighter and and runs cooler.

 

If you're riding on weekends only then the short answer is no, thats enough to keep it fresh for the next weekend. Anything over a couple of weeks of down time then yes, for trickle charging just remember, nothing more than 10 percent of the battery's ampacity. For instance if you have a 30 amp battery use a charger that can output no more than 3 amps. This will prevent you from ever overcharging your batteries.

 

Mine sits on a Battery Tender during the winter, always starts right up.
Without it, there is a parasitic drain due to the security system.

 

You said trickle charger; if you mean battery tender, ok, but I wouldn't put a trickle charger on a motorcycle battery unless it was a newer kind with a full charge shutoff, too easy to overcharge a battery otherwise. The popular green Deltran battery tenders work well, but they're far behind the newer smart tenders you can get today. My Noco smart charger/tender has successfully brought back two batteries my Deltran wouldn't even try to charge, one of which is still working fine two years later, the other a year so far. I don't worry much about losing a battery on a ride because I carry a small lithium jumper battery that can turn the motor over even with the main battery disconnected. If a battery shorts out internally, a jumper won't work, though, there's always that risk.

My '04 sportster is the only bike I have with a slight drain from it's own electronics, and that one I try to put on a tender if it sits more than a week; the others I don't worry about unless it's over a month, and I had one sit for a year and still fire up fine - that was a long time ago, wouldn't do that now.

 

All of our bikes are on a battery tender. I wait until the Harley cools down a little so the wires don't get burned if they touch something hot.
They usually stay on all the time until it is ridden again.