Modern Vespa

My LX150's battery is not holding the charge.
I've replaced the battery, twice.
replaced the stator plate.
tested the regulator (it's fine).

When it has a full charge. I start it (Voltage 12.6), I accelerate (voltage climbs to 13.7) so it's telling me that it's charging.

A couple of days later, it dies. (Voltage 11.3).

I'm at a loss here. Any suggestions.

Thanks a bunch

It sounds like a short somewhere. From the battery terminals back to the ignition switch is where I would try first. I put a small fully automatic charger on mine. This will also help extened the life of your batteries.

Are you using an open cell battery? Any bike with an open cell battery that is having problems should be changed to a sealed, maintenance-free type, i.e. if you have a YB9-B, get a YTX12-BS.

"It sounds like a short somewhere. From the battery terminals back to the ignition switch is where I would try first."

Let me ask you, if it was a short to the ignition, any chance the bike would start with the battery fully charged?

I'm asking because it'll start fine when the battery is charged.

"Are you using an open cell battery? "

Yes I am but this has nothing to do with the type of battery I'm using, I'm afraid, but thanks for the suggestion[/quote]

Have you checked ground from the battery?

The first thing I would have checked is the terminals (obviously fine if the battery has been replaced) next I'd see if it has a bad battery-to-ground connection. Clean it up to be sure.

Good luck.

It is possible. I've seen shorts that will draw a small amount of current that would still allow you to start the motor with a full charge. For example a light that is on will draw a small amount of current and if left on will eventually drain the battery but will allow enough current to start a motor before reaching the minumum amount of volts required.

Does it lose the charge over a couple days of riding or a couple days of just sitting ? I assumed you were riding the scoot.

"Have you checked ground from the battery?"

No, I assumed it was the stator after I took it to the dealership and they told me it was the likely cause. I bought a Stator plate and replaced it.

What should I be checking for? Loose wire, dirty, not connected (to what?)

"It is possible. I've seen shorts that will draw a small amount of current that would still allow you to start the motor with a full charge. For example a light that is on will draw a small amount of current and if left on will eventually drain the battery but will allow enough current to start a motor before reaching the minumum amount of volts required. "

I was considering replacing the wire harness form the battery to??? That's my question.


"Does it lose the charge over a couple days of riding or a couple days of just sitting ? I assumed you were riding the scoot. "

No difference, although I have to say pushing it was no fun. luckily, the guys at Uhaul jump started it, I eventually rode it home.

All right, just because your voltage reads 13.7 doesn't mean enough amperage is getting through the circuit to actually charge your battery. If any electrons are making it through the circuit it'll give you a voltage reading.

Think of voltage as "push" and amperage as "volume" of electricity.

It could be that you simply have a bad ground or a faulty connection such as a badly crimped connector or a wire that's stress hardened and only has a strand or two connecting.

Follow the ground wire and see where it connects to the frame. Unbolt the connection, clean the contact points w/ sandpaper and reconnect it.

Trace your charging system wires looking for obvious stuff- bad connections, connectors dirty,wires almost broken from flexing back and forth, rubbed insulation, a kink indicating the wire was pinched, that sort of thing. Wiggle all connections to make sure they are sound.


If a fully charged battery is discharging while the scooter is just sitting, though, look for the beginning of a short. No blown fuses or burned wires though, so it'll be just starting to happen.

Good luck.

I have read that for the LX150, a good battery is the YTX14-BS. Do you know the difference?

I keeping hearing about this issue on LX series (50's and 150's). There seems to be a drain somewhere on the LX. Doesn't seem to be an issue of the battery, although a good sealed battery can't hurt.

Most folks with an LX just live with the issue by installing a battery tender, but that's just Tylenol for a constant headache. Better to get the issue resolved. Trouble has been in locating such a low amp draw.

It could be...
A poor ground.
A poorly insulated wiring.
A phantom/vampire load (instrument panel, light, etc)

How about the charge on the battery (8 to 10 hours on a 1 amp charge) Also load testing the battery would help to make sure the battery is at least holding a charge. As the old saying goes just because it is new does not mean it works.

Jon

The other saying I like is it is not an issue with the vehicle but rather a problem between the seat and handlebars...

The battery is not the issue here. I wish it was, but it simply isn't. I'm inclined to go with the short. After testing and replacing some components, the wires are what's left.

Thanks a bunch for all your help. I'll tear it apart on Monday and find out how it goes.