Just noticed with my bike this morning that when I press the start button it seems really sow and lazy. It did start and once started was fine, but I got to work, switched off and started again and was still "lazy"
I recently did a voltage test and all was ok. I took it out last monday and was fine so it's not like it's been sitting around for ages.
Could it be the starter motor?

I'd say your battery is on its way out Jo.

I did wonder that. I've had it about two years and been on constant trickle charge, but I didn't connect it back up after last time's outing.

But if it was the battery surely it would start fine after a journey?

you would say so...and so this then points at your lovely generator not giving the berries to the battery - or your journey not being long enough to give it enough of a charge.

get out for a blast or get it on a charger to see how that helps.

My boss nipped home to get his charger so it's about to get a boost. I checked the voltage a few weeks ago and it was fine. Could just be a knackered battery.
THe journey to work was only ten miles so perhaps not long enough.
Voltage test will be done tonight to check it all out.

Is there not something about batteries storing voltage but not enough current needed when the starter motor asks for it

Something like that. A loss of endurance but with out a lack of volts. Isn't it Neo that suggest a healthy battery should sustain full beam for half an hour without going low enough to stop the bike firing up?

A two year old battery should be reasonably healthy, but some people reckon that very long term use of trickle chargers might hurt them over time. I think it's more speculation than fact, but you never know.

Apart from the lights test, another one often suggested is to fully charge the battery, and leave it off of the bike for a number of days, preferably a week. After the initial 'float' charge has dissipated and the battery has settled down to a steady voltage, measure the battery every day for a week and see how quickly it loses voltage. It should lose no more than 1% a day according to most sources, although my my reckoning that would mean it would be effectively flat in about a week. I did this with mine about a year ago, and after the float charge wore off, it lost about 0.01V per day.

First thing I would do is test the charging circuit output. Too low and the battery will never be fully charged, especially on short trips, and too high can damage the battery which can cause it to not fully charge, and/or discharge very quickly. Spec sheet says you should have 13.5 to 15.5V DC at the battery terminals at 5000rpm, usually measured with the lights on. If it's in spec, then that's one thing off the list. If not, welcome to the world of the wire stripper, terminal crimper and soldering iron....

If the charging system checks out, test the battery as above. It may simply have become lethargic. My old one would start the bike, a little less than enthusiastically, and that was fine. Until you stalled the bike and had to try more than once more to fire it up, in which case it went flat.

One other thing might be the cable from the starter solenoid to the starter motor. Probably unlikely, but if it's got grotty on the terminals, you might be losing power due to the increased resistance.

What battery is it?

Keeping it fully charged will get the most out of the battery.

Could just be knackered thogh, espeially if its a cheaper battery.

I had a Yuasa on my ZXR for 10 years before it started to become weak at cranking over, charged up fine but i guess the plates inside were that poor shape they couldnt pass a lot of current quickly (hence the slow cranking)

Cheap one I had on the 24 lasted about 18 months, charging system fine and the Varta thats on it now must be about 4 years old and not showing any signs of slowing down.

Worth giving the charging system a check as mentioned but short stop / start journeys dont really charge the battery well so could just be out of life, hope its nowt major.

I got home OK after having it on charge all afternoon at work. I did a voltage test last night and all ok, so guessing it's just the battery on its way out. It's been on charge overnight so will check it again tonight and will get a new one on order.
Thanks for the replies, just over-panicking as usual!