How could my battery COMPLETELY discharge overnight??? (AA500)

[KENTWALKER58]

And this is with everything turned off, AND with the battery-tender hooked up!

It was at 12.5 one day, the next 00.0 - drained every milivolt off!

The battery is only like four months old.

I've never heard of such a thing in my entire life.

Also, (what I'm sure is) a related problem; before this happened, it appears the stator isn't charging the battery. I checked the stator and voltage regulator according to the workshop manual - both appear good. The resistance readings on both are in spec., the output voltage on the stator is about 50v at 5,000 rpm - just as specified.

So, the stator goes straight to the voltage regulator, the vr goes straight to the battery, via a 30amp fuse. The stator is good, the vr is good, the fuse is good - that's the entire circuit, so what's wrong??

Unfortunately, I'm on my own; there's only one Aprilia servicer in the Portland area (Vintage Scooters), and after dealing with them once before, there's NO WAY I'm going back there again.

Any help?

Thanks,

Kent

[BridgeMan]

Sounds like either bad battery terminal connections, or possibly a shorted cell in the battery itself. I've experienced the latter on an almost-new Varta battery, back in my BMW days. Have you done any electrical work or modifications that could have somehow buggered things up?

Regarding Aprilia service locations, have you tried Motocorsa, on NE Wilson? I know their specialty is Ducati, but I was told by one of their bigwigs (Todd Fitzgerald) that they are an authorized Aprilia dealer, and provide service on Aprilias. Might try calling them to see if they have any ideas--503.292.7488.

[KENTWALKER58]

Well, I'm gonna take out the battery, and check that out, and check to see if I "miswired" anything when I first installed it.

I actually bought the scoot from Motorcorsa, but got a letter from them like 3 months ago, saying they've discontinued selling and servicing Aprilia scooters; which comes as no surprise to me, as I always got the feeling when I went in there that they weren't "into" scooters, just mainly Ducati speed-bikes.

[Bob Walker]

It is unlikely that you put the battery in wrong 4 months ago and are just now having a problem unless one of your connections is loose.
The number one suspect is a bad battery. Number two is your charger went bad and cooked the battery. This brings us back to the battery being dead. Their are a lot of Chinese made motorcycle batteries that have caused a lot of riders to do a lot of walking. If it is made in China don't even consider buying one. My Aprila came with an american battery brand called Yuasa. Their AMG batteries, if taken care of, will last 3-4 years.
If it turns out that the battery is not the problem then get back to the forum and someone will point you in another direction.

[tomd]

when connected to a known good battery showing 12 volts sitting if you install it in the Bike start it on stand and idle to 4-5K rpm it on a Dc voltmeter do you see voltages move from 12-14.2 or so volts as you increase speed of engine ??? if so your charge systems fine and your battery/s are at fault .. with said new battery keep it off the tender a few day in portland in a garage shouldnt need..good luck

[aesmith]

Where's the rectifier in these bikes? Could it be a duff diode somewhere meaning that the battery can discharge back through the regulator and alternator? A check with an ameter will show if any current's being drawn from the battery. Another maybe silly thing to check, does the light switch off in the luggage compartment when you put the seat down? That's one circuit that's still live when the ignition is switched off.

[Reject]

Please, people...keep this thread alive! I'm having the same problem it seems and my local workshop aren't able to solve it.

I'm pretty sure that my light in the luggage compartment didn't switch off...I checked that when I started having these issues. My old battery had a dead cell, but would, after a few tries, still crank up the engine. I replaced the battery with a brand new one ("Euroglobe", never heard of the brand...) but now the workshop says that it's not recharging but they cant find the reason.

When I first installed the new battery I accidently turned it the other way around (ie switched poles). I hope that didn't damage anything. With a full battery, or starter help, the bike runs fine but it wont restart if you turned it off because it drains the battery very, very quickly. Some 5 minutes of riding and you'll notice the directional lights starting going slow.

I have a seperate thread running in these forums, but maybe we can join forces on this one...

[KENTWALKER58]

I do have a Yuasa battery; fully recharged it, put it back in, checked it only about three hours later, and it was already down to 4.0 volts.

[Reject]

Kent: I assume that if you recharge the battery and then just put it aside (ie dont install it in the bike) that it will keep the voltage better? Even if it's unlikely, it could be a bad battery.

More likely, of course, is that something, somewhere is draining power...but I'm just stating the obvious here, aren't I? Check the wiring - if all good, start by pulling cables to the different areas of the bike to see if the battery will still discharge. Tedious work though :\

[Bob Walker]

If you are draining a good battery that is fully charged in a few hours you have a serious power drain. Put an amp meter on the battery cable and start pulling fuses. When the drain stops that will be where you look next. I would also do, as Reject suggested, and that is to fully charge the battery out of the bike and see if it discharges on it's own. AGM batteries can be damaged by fully discharging them. Wherever this much power is being drained you have be generating a lot of heat. Something somewhere is getting hot. The storage light could be your problem but I left mine open all night once and the scooter started right up.

[tomd]

Kent you mayve damaged a diode internal to the Reg rectifier

[KENTWALKER58]

First of all, I have two separate batteries, so it's unlikely they're both bad; still, I'll recharge them both, and see if they hold the charge disconnected.

And then, yes, I'lll have to start detaching things, and see if that stops the drain. The biggest pain-in-the-ass doing that is that you have to start removing body panels, and as anyone who's ever removed body panels knows, it's really easy to break tabs, etc., and the panels never seem to fit properly again.

I'll keep you posted.

Tomd - What/where is the rectifier? I did a search in my workshop manual (on Adobe), and the term "rectifier" doesn't come up.

[rowdyc]

The voltage regulator or rectifier is in the rear of aa500. You will only need to take off rear panel. The working space is not large, but you can remove and install new one. Go with aftermarket brand Shanghai for replacement. It's on many post on this board. If you isn't done it, you will soon like many.

[police1]

Hey there.

I have an AA500, which at times, have given me absolute fits of despair over battery and charging issues. I had to replace voltage regulator(as you known problem), but something happened just today that may lead you to a possible answer. The following is a synposis of the last few days on my bike.

Just got it back from work done by very reputable mechanic. He is good and I know he is very conscientious.. I trust him. Anyway, had it in for wheel changes, but he found the bike with weak start. He found partially melted fuse (30 amp starting fuse along with 20 amp fuse for rest of bike is in batt compartment) Obvious heat generation. After cleaning up fuses, it happened again. He felt frayed wires were culprit or regulator working too hard to charge batt. I told him to splice in new fuses and heat sinked. That was completed, but when i got it home within two days the bike would not turnover. Called and reported findings. He gave me instructions on troubleshooting and explained possible two problems well. Turns out the voltage read off the batt was good, but the amps were pitiful. There was an internal crapout and short happening in the batt, even tho voltage was showing good. I had a talk in order to explain how that can be and it made sense. I replaced the batt, but I wish to mention several things that I found.

-YUASA batts are now made in China too. Mechanic doesn't trust any of the batts on the market, bec he has seen too many problems over the years. He was a fan of YUASA, until they went chinese too

-Bad batts abound and I have regrettably had to accept that those damn things are just horribly made.

-My new batt was bought at a reputable batt dealer here in town. They were good, but I have to tell you guys. The mounts on this newer batt is different than old. They are a better design, BUT the lugs on the connectors for the AA500 will not fit without alteration. We just bent one tab up on either lug. Also, the poles are inverted form standard so you MUST be careful with how you attach. As all of you who have had to change batt on AA500...those damn things can be HELL!!! And that compartment has no extra room at all. The height is close and if you attach the lugs in any other way than the right way, that thing is not going back in!! Since I have changed batt a few times, I DREAD when it goes bad!!

-It is suggested to pull those two fuses in the batt compartment to open the circuit and not fry em'. Well, take that advice!!! Those inverted poles screwed us up. First time that has ever happened. But it caused another issue. Even tho fuses burned just as expected, it also took out the 3 Amp fuse in the front compartment of fuses. Consequently, when trying to start the bike, the thing wouldn't fire. At first, we thought spark plug, but then I realized that the fuel pump HUM that comes on when you turn the key to first position was not HUMMING...That told me fuel pump wasn't on and when we pulled front cover, realized it took out the downstream amp from earlier boo boo of transposing pole wires. Once replaced, bike started right up.

This incident has taught me more about that bike and it was a good thing, but admitting it here might help someone else.

Lastly, not all batts will have this new mount and of course, you can still get old mount, but just realize you have to make minor mods in order to get it back together...I actually like the mount better, but since batt compartment is SO SMALL in this bike, be careful. You do not have to replace the lugs...they can work.

[tomd]

My ETX 15 Big crank battery is a DEKA case and has better terminals on top of it So older Pwr sports battery Dont fit easily (needs ring Terminal on ea wire end is easiest to connect.. Some may ve to flatten there terminals and add a small hole to the flat you just created in order to bolt to Deka battery Top .. Makes you Terminal look like a Fuse link wire in your car