Brake lights stopped working

[Azguk]

Hi,
About 4 weeks ago I was on 2 weeks holiday and the bike was not driven. When I started it up i got every error message possible, drive system cannot be engaged, 12v battery low, lights fault, etc.. I drove it to work and back and the messages never appeared again.

Yesterday I got a brake light fault message and my brake lights will not work. Tail lights and indicators work fine. There is no physical damage and the bike is always stored in a garage at home and in work so nobody was at it.
Any ideas? did it happen because it wasn't driven for two weeks?
Would a computer reset fix it?

 

[Azguk]

Ok so 4 days without brake lights and this morning it just fixed itself.
I did not do anything, in fact I was going to work on it tonight but its working ok now. Cant explain it.
Ill reply if they break again.

 

[Tron]

12v battery low

That's probably why.
If you charged the bike since then, the internal 12V battery got charged, too.
But the battery is a consumable part, so it might work for a while, but will ultimately need to be replaced.
I'd rather do that now than later before you get stranded somewhere because it finally died.

 

[Mr EZ]

I agree, replace it now before it dies

 

[Azguk]

Would the 12v battery really die, or get so low, in just 2 weeks of not being used?
I drive it at least 4 days a week all year round.
It was fully charged before the 2 weeks parked up.
That seems pretty bad that a 12v wont last more than 2 weeks. Bike is only 4 years old.

Still, ill look into it. Like you said, better change it now that get stuck somewhere.

 

[Tron]

That seems pretty bad that a 12v wont last more than 2 weeks. Bike is only 4 years old.

Not really. It's not uncommon to have 12V batteries die after four years, that can happen. It probably should last longer in the CE04 since that kind of has a built-in battery tender, but if it has been subjected to harsh conditions, possible.
They're not that expensive anyway, but if mine dies, I'll replace it with a LiPO4 battery. Although with the built-in tender, I'd need to check if that actually works.
The battery in my GS died after about three years, replaced it with a LiPO4 and no issues since.

Edit: If I recall the manual correctly, there is an error message if the drive battery has to charge the 12V battery three times in a row, indicating the 12V is about to die. Look on page 42+ in the US manual.

 

[pedalmike]

Azguk: I agree with Tron. 4 years is within a median range of service life for a motorcycle battery of the size and capacity of the one used on the CE-04. It's not hard to remove the battery and properly bench test it under load to see if it's still good.

Tron: I agree with your cautionary note about checking the compatibility of the CE-04's charging system with a LiPO4 battery. The AGM 12V battery in my 2007 BMW R1200GS is 9 years old and still going. The service life surprises me. I carry a jump box with me now on that bike until I replace the battery.