Power problem!

[Young rider]

Riding with my lights on for about 20 mins the lights go dim and all the dash is losing power intill and rev it up to about 3000rpm and everything powers up, but when I turn my lights off the battery charges up and there just enough to get her going again.

Would you say there charging fault or the battery is on it's way out?

Also today the bike fan kicked in.

[Dead Eye]

Sounds like its not charging properly. Could be the battery or generator - my money would be on the battery as I am yet to hear of a failed generator. You should ideally be riding around above 3k rpm otherwise the battery won't charge properly and having lots of electricals on like the lights will exasperate any issues

[ChristoT]

Riding with my lights on for about 20 mins the lights go dim and all the dash is losing power intill and rev it up to about 3000rpm and everything powers up, but when I turn my lights off the battery charges up and there just enough to get her going again.

Would you say there charging fault or the battery is on it's way out?

Also today the bike fan kicked in.

You ride below 3000 rpm?!? I cruise at around 6000/7000 - drop a gear!!

If you ride like that a lot, no wonder your battery is going flat - open it up and give it a good blast from time to time! That will also clean out the cobwebs in the cylinders.

Riding that slowly is asking for fouled plugs to boot....

FOCCING REV IT! 

[darrsi]

Wasn't what i would call warm today so unless you had the bike ticking over for 15mins, which would make the fan kick in, then the bike may need a Radflush.

[Dead Eye]

Riding with my lights on for about 20 mins the lights go dim and all the dash is losing power intill and rev it up to about 3000rpm and everything powers up, but when I turn my lights off the battery charges up and there just enough to get her going again.

Would you say there charging fault or the battery is on it's way out?

Also today the bike fan kicked in.

You ride below 3000 rpm?!? I cruise at around 6000/7000 - drop a gear!!

If you ride like that a lot, no wonder your battery is going flat - open it up and give it a good blast from time to time! That will also clean out the cobwebs in the cylinders.

Riding that slowly is asking for fouled plugs to boot....

FOCCING REV IT! 

That is quite spirited riding :P

If I'm having a bit of fun, then sure. But just cruising around I'm usually hovering around the 4k mark

[ChristoT]

Riding with my lights on for about 20 mins the lights go dim and all the dash is losing power intill and rev it up to about 3000rpm and everything powers up, but when I turn my lights off the battery charges up and there just enough to get her going again.

Would you say there charging fault or the battery is on it's way out?

Also today the bike fan kicked in.

You ride below 3000 rpm?!? I cruise at around 6000/7000 - drop a gear!!

If you ride like that a lot, no wonder your battery is going flat - open it up and give it a good blast from time to time! That will also clean out the cobwebs in the cylinders.

Riding that slowly is asking for fouled plugs to boot....

FOCCING REV IT! 

That is quite spirited riding :P

If I'm having a bit of fun, then sure. But just cruising around I'm usually hovering around the 4k mark

On motorways, doing 70 on the restricted, the bike sits at about 6000 revs. "Spirited riding" for me is 3rd gear and 10000revs (or more) 

[Dead Eye]

That's fair enough since 6k rpm = 70mph in 6th on standard gearing but the OP obviously isn't using the Motorways or fast paced roads as he isn't getting above 3k very often

[ChristoT]

That's fair enough since 6k rpm = 70mph in 6th on standard gearing but the OP obviously isn't using the Motorways or fast paced roads as he isn't getting above 3k very often

Touché. I withdraw (as the bishop said to the actress...  ).

[Young rider]

Nope I don't ride under 3000rpm but when stuck in road works and rush hour i have little choice on the speed.

What im trying to say is if lose that much charge with a good hour of riding surely they be enough charge when standing still.

[ChristoT]

Nope I don't ride under 3000rpm but when stuck in road works and rush hour i have little choice on the speed.

What im trying to say is if lose that much charge with a good hour of riding surely they be enough charge when standing still.

Oh, OK fair enough.

Could there be a short in the light loom maybe?

[reillypadraig]

I foccing hate electrics I.e pic below, dodgy Indy.

I'd say check the battery first, won't cost a penny and rule out you having to go looking for problems that might not me there, hope its just the battery!!

[Fazerider]

It's always worth going over all the electrical connectors to make sure they're clean and making good contact, but I agree with everyone's opinion that   sub-3000rpm engine speeds are too low to charge the battery when the headlights are on.
As an alternative to a lower gear, you could consider fitting LED riding lights if you're just using the headlights to be seen rather than to see by. They are intense enough to make sure you get noticed and only draw a fraction of the current that a quartz-halogen bulb takes, wire them to the sidelight circuit or use a separate switch and the load on the battery will be reduced by about 9 amps.