Does my battery need to be replaced?

[tokarev]

My bike battery is giving me hassle.

It seems to only store up a little bit of charge. For example, I left it on charge with my datatool charger 3 weeks ago. It then worked (started bike up etc...), but then the other night I come to it and when I hit the starter in only turns the engine over a couple of times before it gives up and you get that sound of a weak/dead battery trying to turn the engine. I then have to bump start. Shouldnt be like this after only 3 weeks.

Then after a 10 mile ride after bump starting it, if I turn off the engine and then hit the starter it will work. So it must be gaining charge. But If I were to then turn off the engine and try again, then it would seem to be flat again. So is the battery f**ked and cannot hold the full charge?

Extra info: when I attach the supposedly flat/dead battery to my charger, the charger light does not indicate CHARGING it flicks between ABSORB and MAINTAIN for about 20 seconds before then just lighting and staying on MAINTAIN. This indicates to me that the battery is charged up?! weird.

So what do you reckon, new battery or a problem with the bike itself? (hope it is not the latter!)

[Hooky]

Yep, it the battery. (nowt more to said )

[Phil_P]

Sounds like you've got a cell in the battery that is stuffed. It will show a normal voltage until put under the heavy load of a starter motor and then the voltage crashes. Because it shows full voltage under very small loads, it fools the charger into thinking it is fully charged.

Get a new battery and the problem will go away. If you have lots of money, fit an 'Odyssey' AGM type battery. They are the mutts nuts when it comes to bike batteries.
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It is not enough to win, others must fail.
Moto Guzzi 1100 Sport Injection '96

[tokarev]

Cheers guys!

Looks like I'll be getting a new battery then.