UKC

Evening all, hope everyone is having a good week, and if not it's almost the weekend!

If you know the answer this will be a very quick question, if you don't then I probably know as much or more than you simply due to having every possible problem with my last bike....but feel free to post something funny

new bike bought - GSX-F600 - £1350 and (other than this issue) utterly immaculate and I can't believe my luck.

Now I'm hoping I still say that after I get this issue sorted.

Day 2 - wouldn't start. Bumped it, drove to work. Ditto on way home.
Just took the battery out when got home, shows on my charger as fully charged, put it in bike and all I got was a click from the ignition and nothing.

It shows fully charged and on a multimeter shows around the 12.4-7 mark (the lower end after retrying).
Put it on the bike, turn the ignition, battery shoots to 0.00 then over about a minute creeps up again to 12.4.

I'm 95% sure it's a bad battery given that, but I've never seen that creep up bit before.

1/ am i right, just bad battery, don't start worrying it's the alternator/regulator?
2/ if anyone is super clued up could you explain why it acts as it does? is it holding a surface charge and that's it? how come it creeps up?

Anyway...say £50 for a battery on top of the £1350 and I'll call this a win still!

In reply to Scarab9:

I know nothing about motor bike batteries. But lets assume its like a car battery.....

But car batteries are not tested by voltage with no current. They are tested by a specialist tool at high current. In my experience car batteries do just die. So a new battery looks like a next step. Or asking some one to test the current one

In reply to Scarab9:


Assuming it crept up after you turned the ignition off, then it's not an unusual behaviour for a faulty battery (one with very high internal resistance). You load it, and the cell depletes the electrolyte around the plates. You remove the load and the electrolyte recovers.

Could be that the plates have acquired a surface layer that prevents access to the electrolyte; can't remember the details, but I recall it can be associated with storage or low use cycle. I also have a vague recollection that it's reversible, probably by brutal cycling, or a 'conditioning charge'.

In reply to captain paranoia:

thanks. helped my curiousity

In reply to Scarab9:

Knackered battery likely. How much voltage on it when its running? Oil cooled gsx? If so very unlikely to be the alternator, they made them engines properly, never heard of one going, plus I have ridden the suzi oil cooled motors for years and years and never had a problem with mine. Batteries will often hold voltage but not charge if they're broke. Only way to test properly is with a load tester thing

How far is your commute? I wired a cigarette lighter socket to my battery and the plug side to my charger, dead easy to connect it up then. Use it in winter when I'm running heated grips and jacket every day and a short commute, kills battery fairly quick

In reply to Scarab9:

Batteries don't live for ever. As you say, changing it is not that expensive and a sensible first step when you're chasing a shortage of electrical power. It's summer now too (yeah, right) so best change it before it gets chilly.