Battery goes dead in less than a week

[Sfdemo]

Hi,
I have a 2003 GasGas 450 FSE. I know you feel sorry for me, but don't tell my wife, she likes to kick me while I'm down, especially about motorcycles. I've got to fix it before the treaded "I told you so" or I create an unsatisfactory marital encounter.

Among it's problems (and mine), the battery goes dead in less than a week if not kept on a trickle charger. The prior owner, "I just keep it on charge to keep it fresh" (lying mother fr) Tuttle from New Jersey.

With a fresh battery, it will start and runs nicely. Re-starting, that can be a whole other issue and forum post.

When I say dead, I mean, dead dead, ruined, kaput, not to be re-used and will not re-charge. I have not taken anything apart (yet) or messed with any of the wiring.

Any thoughts about where to start? I do have the manual. I was considering un-plugging the lights, horn, ect to start, but I wonder if it is related to the fuel injection or some other system.

No ideas rejected or heckled.
Thanks in advance,
Rob

The key is turned off and all the switches also. I would appreciate any help of where to start.

[memphis2857]

Try unhooking the battery and see if it still goes dead. Could just be a bad battery
If you have already done that does it have a trip computer on it? That's where I would start

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[gasgasman]

Also, you need to isolate different electrical components to see where the draw is.

Leave the battery hooked up.
Remove the fuses one at at time.
Place your amp meter probes into the fuse terminals and check the readings ( key off).
Should be no more than .002A

[Sfdemo]

It has already killed two batteries, both brand new Yuasa models proper for the bike.

I got the first one replaced by warranty, but the next one they refused to replace (properly, since it is the bike and not the battery).

If the battery is unhooked, no draw and works fine when hooked back up.

Once it gets warm, I plan to try any good suggestions I get.

[Neil E.]

Originally Posted by gasgasman

Should be no more than .2A

A bike battery couldn't support more than a couple of milliamps without the engine running (2ma = .002A). With the key off, there shouldn't be any parasitic loss. Has anything been added to the bike and connected directly to the battery? Hour meter? Accessory voltmeter? I've seen electronically controlled heated grips draw a slight current when switched off.

[gasgasman]

You're right. I made the correction on my post. Thanks.

[rosco]

Is it just draining the battery or is it actually ruining the battery? If it is ruining the battery I would suspect the regulator/rectifier. Hook a volt meter up to the battery, start the bike and see what kind of reading you are getting. It shouldn't be any more than about 14.5 volts. I've seen a lot of vehicles that will overcharge and it totally fries the battery and can even take out the cdi box on some vehicles.

[Sfdemo]

I haven't tested it running yet, so I don't know if I have a charging problem. Right now, it is too cold to even want to mess with it.

The bike drains and kills the battery just sitting, unless the trickle charger is attached. It does get to full charge that way, so whatever is draining it is less than the charging amperage of the trickle charger.

[Neil E.]

Unhook the charger and disconnect your negative battery lead. Put a good digital voltmeter set for AMPS in series between the negative post and the cable. See what you get for a reading.

Cars will often have 15 - 20 ma drain when off (radio clock) but their large batteries can support this. Nothing on your bike should draw current when it's off; the battery is just too small to survive for long.

I recommend that you leave the negative battery disconnected. There is no point having the battery charger feed a parasitic drain. In most cases it's best to bring the battery indoors if the bike is in storage. Still use the charger of course.

There has to be a significant load if a new battery goes flat in one week. There must be a sensor or other device on the four stroke engine that is drawing power.

[Sfdemo]

I have he new battery out and indoors. I will keep you posted on what I find