battery flat ?

mopi

Just hoping to pick the right brain here.
Two weeks ago I rode to gym, parked and locked bike as normal. Returned after 2 hours and battery was too weak to start bike, it would power lights and make a feeble effort to turn engine but no more.
Started bike by connecting jump leads from car to removed bike battery, ran for a few minutes, disconnected jump leads AND bike battery (so I could refit it in bike) bike engine died but at least engine was warmed up a bit.
Trickle charged bike battery using jump leads and car. 10 minutes later disconnected leads, refitted bike battery and started bike.
Have bike a good 60mimute + run. Checked voltage at terminals when engine running it's 14.3v. checked for parasitic power loss could not find any (gods bless YouTube).
Battery seems ok now, bike has been left idle for up to 5 days without any issues.
Should I just forget it or do something more ?
Battery is 35 months old, looks fine.

PS. Why won't a bike run without a battery in the loop ? It's something I occasionally did with a car.

Del2005

How often and for how long is the bike usually used? If you only do short spins occasionally it would be worthwhile getting a trickle charger.

I doubt that many modern vehicles will run without the battery as there's so many computers needed to keep them running.

Hotblack Desiato

Jeez, don't run a car without a battery connected (or disconnect it while running) unless you want to blow up the alternator. Can't imagine it would do a bike rec/reg any good, either.

Ancient bikes had magneto (AC) ignition and lighting, so didn't need a battery except to power indicator and horn, were usually 6V, electric start was out of the question on these! My first bike was like this, the rectifier was the size of a Chewit

I wonder if you have a battery cell intermittently shorting out. Anyway after 3 years and having had the battery already let you down once it owes you nothing and trying to squeeze the last bit of life out of it is just asking for more trouble. It will probably appear fine right up until the next time it leaves you stranded!

two wheels good

With lower overnight temperatures the battery power will be reduced so you're not out of the woods yet.

BTW You can jump-start the bike with the battery in place. Taking care not to short the jumps leads on the frame. I wouldn't run the engine on the donor car when jump-starting a bike.

mopi

Thanks for answers guy. As a kid I worked in a motor garage (70s) batteries were swapped and pulled with abandon. Obviously times and car electronics have changed.
I'm not over concerned about the battery itself but was to why it would go from hero to zero in 2 hours.
I ride 3+ times a week and for at least 30 minutes a time. Occasionally bike will be idle for 7 days.

Hotblack Desiato

mopi wrote: »

I ride 3+ times a week and for at least 30 minutes a time. Occasionally bike will be idle for 7 days.

You'll need to be trickle charging that, especially in the winter.

GBX

Pick up one of the Lidl/Aldi ones. €20 - sorted!

Emmersonn

If there is nothing drawing from the battery when the motorcycle is turned off, check the electroylite level if a "wet" battery. If this is ok ,make sure the motorcycle is turning out at least 13.75V when running. If you did not have a loose connection when battery failed to start initially I would think the battery is on the way out. I have two motorcycles here both with alarms and can leave them for 2 weeks without charging (trickle) and both will readily start.

mamax

GBX wrote: »

Pick up one of the Lidl/Aldi ones. €20 - sorted!

I use one of those and they are cheap and cheerful and work very well, another thing I do is remove the fuze from the heated grips while bike being trickle fed to make sure there is no draw on the battery.

Hotblack Desiato

Heated grips need to go off with the ignition, because it's too easy for you (or someone messing with the bike) to leave them on and they'll flatten a battery quick enough

No drain on the battery if they're wired up correctly.