Shovelhead Battery

Mike Roen has his Harley Davidson Shovelhead on the lift to talk about battery replacement, battery upgrade, and the importance of disconnecting the battery ground cable. The negative battery cable should be disconnected prior to most any service or repair on every model motorcycle or automobile.

Mike set up an easily accessible, quick disconnect ground at one of his transmission end cover studs. The stock ground cable mounting location is on the top of the frame, near the top of the right shock.

Mike didn’t change his battery ground location because disconnecting the stock location is too labor intensive. He set up a “quick disconnect” so he could disconnect the battery as quickly as possible if the starter solenoid gets stuck out.

Unfortunately, the “run away starter” is a common problem for Shovelhead models. What happens is the ignition switch is switched ON. The start button is depressed. Then, the starter shaft stays engaged and spinning until the battery cables begin to smolder and the battery dies. This results in damaged battery cables, excessive wear for the starter motor and the starter solenoid, and a smoldering, dead battery.

This condition is not common for every Shovelhead on the road. Some seem more susceptible to the condition than others. However, it is more common for this to occur when starting the motorcycle with a weak battery, poor battery cable connections, or if there is an alignment issue that obstructs the starter shaft and starter bendix from moving freely.

Mike’s year group Shovelhead calls for a large, conventional, lead, acid battery. There is nothing wrong with still using this style of battery. However, it does require a little more attention and maintenance. Also, if the voltage regulator ever fails and the motorcycle overcharges, a conventional battery will overflow acid out through its overflow tube. Hopefully the acid ends up on the road and not anywhere on the motorcycle. For this reason, a lot of Shovelhead owners will opt for an updated, maintenance free battery.

If installing one of these smaller batteries, it is important that you take the time to properly shim the battery so that it is secure within its battery tray and covers. The battery shims that Mike demonstrates are an excellent example. It’s best to use rigid foam pieces that can be cut and trimmed to size. Do not make shims from anything hard that can eventually damage the battery.