Battery issue

[George]

I am no mechanic but maybe someone can give some advice. I am on my second battery this year on my 2013 650 GT., The first one I replaced because I thought it had died the second has reacted like the first, after several days of non riding it will not crank and gives every indication of very low battery but it shows 13.8 on my volt meter. When I jump it it starts and runs fine and restarts the next day But leave it for several days and it won't start and acts like a dead battery, Its a mystery to me and never happened prior to this ridding year. Any ideas?

 

[EvilTwin]

Could have a parasitic drain. Are there any add on items that might be the culprit? Otherwise you may need to invest in an amp meter and see if there is any substantial current flowing when the bike is off and the key is out. You could also try pulling whatever relays are there as well, always possible one got "stuck".

 

[Ceesie76]

The 13.8 volt reading may suggest a poor cable connection at either the battery or the starter motor.
And 2x on the parasitic drain check.

 

[Gianz]

Hi Guys,
C650GT 2019
On this same topic, I had a battery gone south due to GPS parasitic drain ( the little Garmin transformer w/o the gps ). Replaced the battery with Lithium one (everything went crazy on the electronics), pulled it out and replaced w/ original BMW agm and after a couple of weeks not riding it was totally dead w/o any parasitic drain. Charged it up and upon installing it back hell broke loose !!!!! The starter would crank w key in off position and engine would start, switch key to run and run bike w no problem but it would not stop by putting key in the off !!!! Some crazy thing is going on and would hope to hear some comments before having to take it to a dealer

 

[Pappy13]

Trace your Negative cable to the point it connects to the frame, remove the cable, sand and clean the connection point and cable, re-connect and test. Have had this issue with multiple bikes and often it is just the cable connection (check tightness at battery on both post as well).