Charging/Battery:

[MrMessy]

I have an ER5 that I have just bought as a runabout. I am having trouble starting it sometimes? The other morning after a freezing night it would not turn over so I bumped it off, it would not fire up when I wanted to come home. It spun over but did not fire up. Left at work then this dinner time it fired up O/K then this evening it only just fired up! I am going to check plugs and change the air filter has it is pretty mucky and therefore possibly flooding. It runs great once started. I have checked battery voltage after charging and it is just over 13V(sealed battery). The bike is charging over 16V with lights on. This seems high? It is not blowing bulbs and rev counter is working. Rectifiers are prone to failing on ER5's. Do they just fail or do they gradually get worse and fry the battery(also taking out revcounter). If the battery was overcharged would it turn over starter?
Any advice greatly appreciated.

The rectifier seems to have gone mate. An alternator gives out around 14 to 14.5V max. I'd give the battery a proper charge. You should get around 13V when testing it offload. Hope this helps. I'll pm you some pdf docs to help you out.

yeah, 16V is too high.

As an aside... does it have an alarm? Maybe the immobilizer is on?

[MrMessy]

No immobiliser or alarm. Checked this morning with fully charged battery and lights on 18.6V! So going to get a rectifier unit before it does any damage!

[Biker Biggles]

Sounds like reg rec.That sort of output will start to fry the battery too.Have you noticed it getting hot?

[MrMessy]

It was getting warm last night when I was checking charging rates!
Ordered a new one from Electrix, probably end upgetting a battery as well.

Sorry to hijack but my K3 650s wouldn't start this morning Usually it starts first time every time but after last riding it Wednesday evening I went to it this morning and it just churned over without firing, nearly caught the first time and I was maybe a bit keen to get off the starter but after that it didn't even get close, stopped trying before the battery went completely dead.

Any ideas? Is it just flooded? It does stay outside under a Stormex cover and it has been pretty wet recently but I don't often ride at w/e's and if it's been wet/cold then it hasn't made a difference when firing up on Monday.

If it doesn't start tonight after resting all day what next? I don't have a charger unfortunately!

[Biker Biggles]

First get a charger and charge the battery.A half decent trickle charger should be thought of as a bit of essential kit IMO.Then find out why it went flat.You need to check the charging system(search on here for that)and make sure that is OK,then check your battery isnt a bit sh&gged.Winter weather always seeks out any weakness here,but it may be nothing worse than too many short trips allowing it to go flat.
I would avoid just buying a new battery without checking the system,as an overcharging reg/rec will wreck the new one too.

Thanks for that Biggles, I'll try to track down a charger today, not proving as easy as it sounds though!