BMW R1200R R1150R/T F800 K1200R R1100R/T R1250R RnineT Message Board

Greetings all!
Newbie here so please be gentle.
I just picked up a Rockster, it's my first bike.

Guy I bought it from said he in put a new battery (and did other regular maintenance stuff) about 6 months ago. When I bought it he trailer-ed it over (we live quite a distance apart) and it wouldn't start from the battery so we ended up push starting it (he said he stupidly did not realize he left the ignition on for the two hour drive and it just drained the battery). It seemed to check out fine otherwise. Let it run for a bit and then I parked it as I it was still cold and I just didn't have the time.
A week later went to start it up and wouldn't start (expected) so I put it on a charger for 5-6 hours, took off charger and it cranked right up, several times. Ofcourse, it was raining that weekend, so I didn't take it out, and did not leave on charger.
Another week passed, went to crank it up today hoping to go for a ride and not enough juice to get it started.

Question is this, is this battery just not going to hold a charge now? Or do you think this is just a bad luck issue and if I charge it, and then get it out for 30-60 minute ride immediatley, it will be fine?

I'm thinking of just biting the bullet and dropping bucks for a new one just to give myself some peace of mind.
Would really hate to get out to the middle of nowhere and have it not start due to the battery.

Thanks in advance!

I would charge it again. Probably the worst thing you did is start it up a couple of time and NOT ride it. Starting the bike takes alot out of the battery. You need to ride it for approximately 20 minutes just to get the alternator to charge the battery back up. You could take the battery out and have it tested somewhere like Advanced Auto if you have no way of doing it at home.

Ride for an hour, non-stop (don't shut off motor), and loop back home. Measure battery Vdc. Do not connect trickle charger.

Next day, measure battery voltage, then start the bike for a ride. If it does start, you might be ok. If it doesn't start, then battery is old, charging system weak, or there's a current leak somewhere due to wire short or accessory wiring problem.

Make sure that you charge up the battery as well as you can before you take it in to be evaluated. It sounds like it is toast, but you could get lucky. Many bike owners buy a new battery when they buy a used bike just to start out knowing it is fresh. Bikes sit around a lot which is not good for a battery. Buy a battery tender that automatically trickle charges and periodically hits the battery with an anti-sulfating charge. These are known as 'maintainers' and many owners install a charging fitting on their bike to easily hook up and disconnect it every time they go out.

Nice first bike! I just bought one and it is my 7th moto! Take the motorcycle safety classes and buy the book 'The proficient motorcyclist' by David Hough. It should be called 'How not to die on a bike'!

Best of luck!

Thanks for all the input!
I went ahead and ordered up a PC680 just to give myself some peace of mind.
If it arrives today plan to get it in this weekend.

Cheers!

Let it run for a bit

Not trying to be picky but don't let it run for a bit.
Numerous threads here about the consequences of letting a BM idle for a length of time without any air moving over the motor
The riders manual for my bike says ...

Letting it run for a while won't replace the current use to start it but could cause real problems from overhaating.
See viewtopic.php?f=2&t=27564

If you were already aware of this BM idiosyncrasy, my apologies.

Ian