Battery volts good amps Bad?

So, I'm thinking the battery is just ready for replacement. I haven't tested specific gravity, but I'll tell you what it's doing:

It charges great, the charging system seems to be doing fine. I can pull the battery off, put it on the charger and the charger says, "Yeah, you're all good to go". I can measure with a multimeter and it says the same.

All the lights are beautiful and bright.

It runs perfectly well when kickstarted. VERY well, in fact.

It doesn't crank. Sometimes it will a little, but for the most part.. voltage is fine but it just doesn't want to crank.

Starter connection is sound, by the way.

What do you think. Can a battery charge up on volts fine but be losing it's ability to put out amps?

Check starter brushes and armature.

Yes. But your lights will dim when you try to crank if that is the case.

If they don't, then work your way through the circuit, all the way to the starter. At some point you'll find a voltage drop. If you don't by the time you get to the starter housing and stud, it's likely time for new brushes.

-Duck

My lights DO dim when I try to crank. I'm just sayin if I turn the key and turn on the lights, they're bright as they can be.

If I hit the starter, sometimes it'll kick ok, but usually it'll just do a little bit of a lunge and call it a day, and the lights go dim until I release the button.

Cardin wrote:

My lights DO dim when I try to crank. I'm just sayin if I turn the key and turn on the lights, they're bright as they can be.

If I hit the starter, sometimes it'll kick ok, but usually it'll just do a little bit of a lunge and call it a day, and the lights go dim until I release the button.

Couple questions:

1. How old is the battery?

2. Got any hop-up goodies - specifically high compression pistons or a hot cam?

Yep, a battery - especially an older one can be volts rich and amps poor.

Accelerated decrepitude (old age) of the starter motor brushes could be gumming up the works.

A short duration cam will hold the compression on th estroke longer, making it more difficult for the starter to spin the motor...

Post edited by: Pterosaur, at: 2006/06/09 18:14

Alright, I think I'm on the right track.

I'm pretty sure the battery is quite old... I bought the bike with the battery. I just wanted to make sure I ruled out some things before I went and bought a new one, but I'm feeling pretty confident that it's time.

You can always test the battery. Put your voltmeter on the battery posts. Not the connectors or cable but the bit of material that disapears into the plastic.

Watch your meter when you try to crank. If it drops, it's your battery. If it doesn't drop then you have a poor connection either on the ground side, or somewhere before where the lighting circuit splits off.

Sure they can go bad this way. Use ducks advice and check the voltage on the posts as you try to crank the engine. Otherwise there are battery testers on the market. I bought a good one from OTC tools for about $200 that will test any battery and tell you its volts as well as AHR, CCA ect. I use it often on my truck so I know if I need a new battery before Winter sets in. Also use it on all my motorcycles. Quite often a battery after charging will seem fine with a meter check at about 12.5v, but when a battery checker is used on the battery it will show the AHR at zero. No amps, no starter rotation.

Thanks for the advice, I'll check it out.


Hey hey, RonKZ.. you're just a stone's throw over in Wheatridge.