battery charging

[(RIP) pastyman]

went out this morning and after a mile or so, Bertha just stopped, no ignition lights on and everything completely dead. I suspected the starter relay and after a bit of buggering around the ignition lights came on but she would not turn over. I managed to bumpstart her and got home. a check showed the battery was pretty flat and with a jump from the car she fired up straight away..... so... The battery is a gel type and only a year old so should be OK.
I fitted twin headlamps a while ago and my guess would be that the lights are taking more out of the battery than the alternator is putting in.
Check on the battery with the engine running shows about 13. 5 v.
I seem to have to options,'
switch one of the headlamps off
find a way of increasing the output of the alternator, or should it be doing better ?
Any suggestions please.

 

[John Armstrong]

What engine speed gives the 13.5 v?

Read this thread and the links in it:

http://www.ukgser.com/forums/showthread.php?t=199804

 

[Thunder]

Sounds like the twin lights may be having an impact.

Just to confirm is the 13.5v reading with the lights on or off?

Has the bike a standard or a high output police type regulator?

 

[(RIP) pastyman]

thanks for the replies.
With everything off the battery was reading 11.7 v, so battery flat
engine running at over 3000 revs 13.5v.
the thread posted by shep seems to have answered a few of my queries.
I use the bike at weekends, usually on a sunday and always run with the lights on. usually at reasonably fast pace and no probs encountered until today, Sounds like I just have to charge the battery up more often.
I will also put one of the headlamps on a switch so that I can ride in the day with one and switch to two for night riding (which I rarely do)