I have a 2021 FXLRS and have an unknown (what I believe to be) electrical issue. My bike has been dead multiple times in the past 2 months. The first time it happened, I had to buy a battery tender to get it charged enough to start. I took the bike to the dealership to have the battery tested and they said it was dead but fine.

So fast forward 2 months and the bike has been dead 2 more times including today. I have never had this issue until the past 2 months. I have even went over a month once with not starting it and it was slightly sluggish but turned over no issue.

I had previously asked the forum about my LED blinker inserts and the consensus is that it wouldn’t drain the battery. So now I have no idea what to do. My personal guess is that it’s just a bad battery despite the dealerships “test”. I didn’t use my usual dealership (it closed).

I have a trip in late September and really need this resolved so any help is appreciated!

 

Sounds to me like a bad battery, first thing I would do is swap that out

 

Two bad batteries, you have to ask what are the odds! Possible but not likely. The dealer should have also checked the battery charging voltage was ok when running ie. about 14V… this needs to be rechecked. There is also a possibility you have a slow drain on the battery either from an accessory (eg. MobilePhone charger left on? Even these can have a quiescent current while not in use if not switched off, enough to draw down a battery over a month) or from a fault. This can also be checked by someone that knows what their doing with a multimeter. Both checks would be worthwhile before committing to another battery 🤞🍻.

 

You need to get you a AC,DC,Ohm,Amp meter so you know what's going on. You also need to check battery connections occasionally.

A battery at 12.3 is considered discharge as far as starting. And if you leave a light on and drain the battery to say 2 volts, that's dead.

From my experience with cars, about half the time, that seriously damages a battery.

Charge your battery on a maintenance charger 24 hours. Remove the charger and turn on the headlight for a minute and off.

That kill the surface charge from charger on battery. Battery should read 12.8 to 13. Now watch meter and start bike. Meter should not drop below 9.1 cranking. That shows your cranking amp of the battery is OK.

Now rev motor to 2000. Voltage should be about 13.5 to not over 15. Charging and regulator are fine.

Finially, a battery should be OK for a month. If you don't use bike in that time, put the maintenance charger on.

However, don't just leave it on all the time. Doing that will guarantee the last start you get on that battery is at home and it will leave you while your out.

And if all checks out OK and battery is going down, take. your meter and set it to amps and with key off remove negative and check it for a short. Old bikes drain about 150 milamp to ECM, Speedometer, alarm. News ones about a 1/3 of that.

They all with alarm show more that will even make a spark when you first jump negative thru meter to battery but that drops after 30 seconds. That's normal.

 

There's certainly a chance that your replacement battery is defective.

But, I'd suggest using a meter and checking for a parasitic power draw when the bike is sitting unused. Use whichever battery post you can best get at, and with the bike shut off, measure what it's drawing amperage wise. The normal draw should be something like 20-50 milliamps.

 

I may have not explained this properly. I still have the original battery in the bike. I just tested it and they said it was fine. I’m considering just getting a new battery. The battery that’s in it is the original one that came on the bike.

I also spoke with a tech that I trust. He also mentioned the multimeter but also said from the description, he thinks it’s likely the battery since it’s the original one that was shipped on the bike. He said if it doesn’t fix the issue, to start testing with a multimeter.

As far as accessories go, the phone charger is connected with the stock usb on the neck of the bike. It should power off when the bike is off and that’s what Harley is claiming. From what I can tell, that’s true since it powers off when the bike is off.

The tech I know, plus the dealership, both said it shouldn’t be an issue with blinkers, headlight, or taillight because that’s controlled with BCM and isn’t powered with the bike off.

So I guess I’m starting with a battery this Friday and we report back.

I’m also moving to different lighting when I can afford it. It sounds unlikely that the lighting has anything to do with the issue but I’m still moving to something with a good track record. I keep being told to use custom dynamics so I’m gonna give them a try. I’m gonna order blinkers and taillight bezel. I’ll probably just go back to the OEM taillight too.

 

I have a 2021 Sport Glide and I had to replace the battery this year. I would say that replacing the battery will fix the problem. When a battery gets old it may take a charge and start the bike, but it will discharge if the left for any length of time without a tender on it. That is where mine was, I felt that I couldn't trust it to hold a charge throughout the day, so if I rode it to work there may be a chance it wouldn't start to bring me home, so I replaced it. Eventually it will get to a point that it will not take a charge and could leave you stranded. Three to four years is about the max life for a motorcycle battery, especially the smaller batteries on a Softail.

 

Get a better test of the battery, you can’t test a dead battery. Charge the battery fully so that it reads 12.6 volts, then take it to an auto parts store and have them do a load test on it. Replace if bad, and have them fully chsrge it.


I install the new or tested good battery. Then start the bike, and rev to 2,000 RPMs and measure the voltage it should be greater than 13.7 if the chsrging system is good.

And anytime the bike is used once every three days, hook it up to a battery tender.

 

I would not expect a 2021 battery to be bad/weak, yet. But it's coming, so it's also certainly possible.

From your response, I take it you either do not have a multimeter or are not comfortable with the work of checking or chasing a parasitic drain?

 

Thanks. I’m waiting on a new battery right now at the dealership. Your thought process is exactly what I was thinking. I don’t wanna not trust the reliability of my bike.