hi guys, i'm just wondering what the normal voltage should be for 2009 sportster battery?i've got 13.10 and my local dealership said i should be around 14 volts. the owners manual says a fully charged battery is 12.70. cheers from montana!

 

12.8 volts is normal.

If you get 13.1 V it is probably okay. My guess is that's recently after riding/charging where the residual charge is a little higher.

It should be above 14 V when the bike is running.

 

What he said.

 

+2. Depends on if you are talking about the bike sitting, or with it running. At 2,000 rpm, it should be close to 14 volts.

 

fully charged 12 volt battery at rest - 12.9 volts

bike running with high idle - 14.5 volts

use real tools, not bike gauges!

EDIT - a battery that measures 12.7 volts at rest is about 25% DISCHARGED! These are standards that the BCI have set. (battery council international)

 

I recently put a USB charge port on my 2000 Sportster and it has a digital voltage display. I was surprised to see only 11.8-12.5 volts. The bike has been starting fine, headlight is fine, I would not have suspected any problems, I thought possibly the USB charge port regulated to 11.5-12 volts like computer power supplies, but when I checked at the battery when running I get the same, right around 12 volts. What should I look for, my first Harley so I'm not familiar with the common drills for trouble shooting. Why am I not having starting problems?

Thanks!

Steve

 

 

It's a Fluke and I trust it, I just went back out to check the battery at rest, been sitting an hour or so since I ran it last, 12.2 volts with the same meter. The USB charge port is hard wired and shows the same 12ish volts when running. The battery was in the bike when I got it, has been sitting for a couple of years, not fully charged but not dead when I got it, 10 volts or so, and required a few ours on a 1 amp charger before it would crank the motor normally, that was in February, I have put about 2ooo miles on since then, starts great hot or cold. Could the battery be pulling it down?

 

I checked the stator and have 50 volts AC at high idle, that seems ok, I'll try to check the voltage regulator. It is still starting fine, but I put the meter on it and shut it off, the battery voltage was at 11.8 running and went up to 12.2 when I shut it off.

 

There are a couple of Stickies in the Tech Electrical section which guide you through checking your charging system. Use them to diagnose any problem. What are you using to measure those voltages?