Hello. I asked this question yesterday on a different forum and didn't get much response.

I have an 07 low rider. I had this same issue last winter/fall when the temps started getting down around 40s and 30s.

I keep the bike in a garage every night, and usually have it hooked up to a 2a battery tender. Lately, as similar to last year, when I try to start it in the mornings when its cold, it wont turn over properly. It turns real slow and obviously starts to kill the battery. I did not check the voltage on the battery prior to starting it those days.
Last night, however, I did. The voltage was about 12.8v after sitting since about Tuesday without being on the tender. I charged it for about an hour and unhooked it, it was sitting at about 13.12v which I think is pretty good.

I was told my oil type shouldn't be affecting it, like I thought it was. The manual reccomends different oil types for colder temperatures, thats why I thought that first.

Can anyone recommend something I should look at? On a side note, I did replace the battery last summer, prior to this happening. So I'm wondering if I just got a dud.
Also, once the bike starts (jumper box) I ride to work. I park in a storage room in the parking deck that has heat, and the bike has no issues starting up 9 hours later.

Thanks for your help everyone.

 

There must be a reason the moco recommends a lighter wt oil for colder temps. I'm goin with a 15/40 wt oil for the winter as the 20/50 seems to make the motor strain when it gets cold.

 

anybody else have ideas?

 

take the your bike to a harley dealer and they can check the cold craking amps on your battery. it's the only free thing my dealership has done for me. mine was doing the same thing and it was always hooked up to my tender. i got 7 years out of the battery and just replaced it.

 

you can check the cranking amps yourself by putting the voltometer on the bike prior to pushing the start button. What you would do (easier if you get a friend) is to hold the connectors of the voltometer on the battery (shoud register 12ish) and then attempt to start the bike. It should not go below 10-11ish. If it goes down to like 5-7 you have a cranking amp issue and the likely reason you see it when it is cold is because it takes more to turn the engine.