Understanding the Harley-Davidson Battery & Charging System
Bob LaRosaDescription
Unless you have a kickstart, you’ll need a battery to get your Harley started and to keep it functional. With that can come some Harley-Davidson charging problems.
Bob shares some tips on battery replacement and upkeep. Batteries have come a long way since we shot this video. HD makes a great one but make sure to check out Yuasa and the lighter longer-lasting lithium batteries made by several companies.
Here’s another look and a great project for newer Twin Cams:
Go back to school and learn all about Harley Electronics with this project:
Make sure to review all Maintenance Videos for your make and model.
Milwaukee Eight Touring
Touring Maintenance Twin Cam and Evo
Trike Maintenance
Milwaukee Eight Softail
Softail & Dyna Maintenance Twin Cam and Evo
Sportster Maintenance
If you haven't already noticed Harley Davidson no longer manufactures motorcycles with kickstart assembly. This makes the battery in your motorcycle an integral part of the electrical system. I highly recommend only using direct Harley replacement AGM formatted batteries. Whenever you purchase a new battery and install it in your bike, make sure you take the time to not only date the month but the year that the battery was purchased and installed in your bike. The larger battery I have on the table belongs in all the newer touring bikes. Can be purchased directly through the dealership network. I'd like to take a minute and just show you a fuse pigtail assembly bolts directly to your battery on the 10 millimeter bolts. This is used for daily storage and regular battery maintenance. When it comes to chargers, I like to use the Battery Tender Junior, which also comes with that type of pigtail harness. I also like to use for a few dollars more the Battery Tender Plus. The differents in the componentry and the design offers features that the junior just does it. It also comes with a set of alligator clips. These are used when the battery is removed from the motorcycle for any extended period. We'll hook the negative and the positive. Again, it is a fuse setup. I'll plug the battery in. Let it get a little charging time. I'm going to get some work done. Let's take a quick look inside the Harley Davidson charging system. I'd like to know this charging system is not an excited-field as found in the automobile industry. It is a through generator style charging system which means the engine has to be running in order to return input voltage back to the battery. As you can notice, I'd removed the outer primary cover, drain the fluid. It's not part of a basic service to remove this cover but if you ever do, always make sure you replace the auto primary gasket. With the cover and the gasket fluid removed, I've already removed the clutch primary chain assembly that you're familiar with. I'm going to remove the outer magnetic rotor shell. Be very careful with this. It is a steel shell with magnets that are only glued inside the shell. It's clearly stamped, no sharp blows. If you drop this, the likelihood of you having to replace it is good. With the outer rotor removed, we have a nice, clear view of what's known as the stator winding. What this basically comes down to be is a coil of wire that has two separate ends leaving the engine crank case, where there is no contact anywhere along their path until it hits the voltage regulator. Although Harley Davidson has used a number of amperage output style charging systems over the years, they basically remain unchanged from the 18 to the 22, to the 32 amp, to the new 48 amps, and I'm sure they're only going to get bigger and stronger as our voltage requirements grow.
I have a 2015 tri glide is it important that the cc be 400 or can it be cc 385?
Hi Guys Im having problems with starting my 2010 Harley nightster. ! day it will start and everything is fine. Then I go to start her next day and all it does it turn over, wont start..any ideas?
I have an 08 Sportster 883 I have had the stator check and it checked out fine the regulator checked out bad I replaced it. I had to charge the battery up then I drove it approximately 3 miles it was cutting out like it wanted to die after I got it home and turned it off it started back up but the next morning when I went to start it it just click click click click
Hello, I've recently purchased a '91 FLHTC and I'm having done low voltage issues. The bike always cranks over and starts fine, but while idling the volt meter on the dash will go as low as 8 volts. While driving, the volt meter will sometimes read 12, sometimes 12.5. This is all done with the passing lights and stereo on. If I turn off the passing lights alone, the volts go up to 13 and stays there. My question is, should I and can I put a larger amped charging coil in to replace the stock 18 currently in it? Thank you
How much compression can the OEM starter handle on a 03 Roadking. Just put a 95in.Kit in it and decked the heads .040 with a over size exhaust valve. Having intermittent trouble cranking. Just installed new AGM battery and problem still exists.