Does anyone have a idea what might cause the battery on my 2016 Bonneville T100 to drain while sitting in the garage. I have a Battery Tender USB Charger Adaptor for my phone on the battery. Last week, I rode about a half a hour and noticed the phone wasn't charging. The cable felt warm but I didn't really think about it. On Friday I went to start it and the battery was flat. I used the trickle charger overnight and it cranked and rode fine. I had the battery checked by Batteries Plus. While in the motorcycle, they checked it and it showed the battery as unstable and unable to be checked. It showed 12+ volts out of the motorcycle, so they wouldn't do anything about replacing it under warranty. so I brought it home and parked it in the garage. I checked the USB cable that was plugged in the Battery Tender USB Charger Adaptor and it was still warm even after sitting in the garage after 5 hours. It would not charge the phone. I replaced the USB cable plugged into the Battery Tender USB Charger Adaptor. I let it sit overnight and the battery remained charged overnight. Today, the battery is losing it's charge during the 90 degree+ heat in the garage. I'm thinking it's charging ok, but has a short that shows up in the heat. Any ideas?
Sounds like a bad battery. 4 years out of a battery is expected. Any battery that is not fully charged all the time gets damaged over time which is normal. That is why it is good to keep a battery on a battery tender. I always plug in my tender whenever I am not riding my bike. My batteries have always lasted many years. Or it might be a bad voltage regulator.
Sounds the USB charger cable is at fault take it off or disconnect it and see what happens to the battery which should be reading at least 12.5 volts
The battery tested as close to perfect. @ Batteries Plus. I have an appointment@ the dealership to have it checked out
I have another USB charger lead on the way. Maybe that will take care of it. I currently have the USB charger lead on the battery without the USB cable plugged into it. The battery is not discharging now.
USB chargers will still draw some current, even when there is no USB device connected (it contains a 12V to 5V converter circuit) - although with a device connected it could easily be pulling several amps And T100 has a pretty small battery Unless you absolutely HAVE to have ability to have it be live with ignition off, it would be better to have it connected to an ignition-switched circuit. When you get your new one however, if you have a multimeter available, you can always test the current it draws with no USB device connected (connect the negative, set multimeter to read current and connect the probes between the battery positive and the USB positive terminal; be sure to only connect like this and remember to switch back to volts - if you connect meter to a voltage source while on current, you will blow the meter fuse)
You can use the same circuit that supplies your Horn/Turn Signals/Brake Lights That would be the Orange/Green circuit which will only be active with ignition on and have plenty of current available. You can tap that on the main harness side of the connector that feeds the right bar switch inside the headlight bucket, which might be a convenient place for a front end mounting location - or the wire that goes to the horn itself, or the one that goes to the Turn Signal Relay or to the REAR Brake Switch (NOT the light - has to be on the Orange/Green at the switch)
All fixed up. Good as new. Replaced the USB battery tender. The battery is holding the charge like it's supposed to. Thanks everyone for the insights.
