New Battery Dead Overnight

[RED RUNNER]

Bought a new Yuasa and charged it overnight with the Battery Tender Plus. Bike started up fine the next day. A day later, the battery was dead. I checked out the drain on the system with the bike off -- its drawing 3 miliamps, if I'm reading my meter correctly. I run no after market electrical farkles. Is that draw too high? If so, what could be the culprit?

[checksix]

3 milliamps is not going to discharge your battery overnight, assuming you read the meter correctly.

What's the voltage reading now in the "dead" state?

[HispanicSlammer]

Spec for the current leakage inspection on the 5th gen is 1.2 mA max, thats removing the ground cable and putting the volmeter on mA between the ground post and the ground cable.

it says if you your leakage is above this spec value you have a short in the system, locate the short by disconnecting connections one by one and measure the current, I assume they mean remove the fuses one by one? then harness connectors?

[RED RUNNER]

3 milliamps is not going to discharge your battery overnight, assuming you read the meter correctly.

What's the voltage reading now in the "dead" state?

Can't check it because I've pulled the battery to charge it again. Once charged I'll let it sit by itself for a day or two to see if it discharges on its own. If I have time I'll take the battery to get tested.

If the battery checks out I'll reinstall and run it down, and test again. I'll check my connections and fuses.

I've got a power commander III. I just loaded a map recently; bike ran fine with the new map. I wonder if I messed something up in the process.

[Conedodger]

it says if you your leakage is above this spec value you have a short in the system, locate the short by disconnecting connections one by one and measure the current, I assume they mean remove the fuses one by one? then harness connectors?

That is how I trouble shot an issue with a car years ago. Started pulling fuses while checking the current draw. Turned out the power antenna was not turning off when it retracted. I rewired it to kill power with the ignition switch. Just had to make sure the antenna was down before I shut the car off.

[hockeypuck]

RR,

If the switch-off current really is 3mA the battery should be able to provide this forever. Look at it this way: a typical motorcycle battery is rated at 12V, 12 to maybe 20 Ah. If the quiescent current is .003 A, a 14 Ah battery will supply this for 14/.003 = 4700 hours! In practice it doesn't really work this way but close enough. Overnight shouldn't be a problem and the 3mA sounds like trickle current being supplied to your ignition module. I would expect it to be somewhat higher, maybe 20 mA. There are a couple of things that I would do to diagnose the problem. First, go to Lowes, Home Depot, or whatever home improvement hyper-store you have in your area and buy a $10 analog multimeter. Sperry makes these for the chain stores and they are surprisingly useful. Repeat the switch-off current drain test using the cheap dial meter you just bought this way: Key off, remove one of the battery leads (doesn't matter which as long as you pay attention to polarity) and attach a meter lead to the loose battery lead ring. Then quickly tap the other meter lead to the battery post that the lead came from. If the current is really 3mA the meter needle will jump across the scale then settle back to around 3mA. The advantage to using an analog meter is the needle movement has inertia. Suddenly completing a circuit of significant ampacity doesn't make a dial meter go all goofy. Digitals are great but tend to be too quick. By the time you realize something bad is going on, the meter fuse has blown and you get to start over. I keep a cheap analog and a digital around for just this purpose. If it stays high then a parasitic drain exists-probably not a short-that is killing the battery. As one of the other posters said, it then becomes a fuse-pulling game.

Assuming that this test doesn't get you anywhere, I would suspect the alternator. Have you tested the output? It should be >=13.5 VDC regardless of load. This can be done in the driveway or use the cheap meter by taping it to your gas tank and running a couple of small leads to the battery top. Then you can ride the bike around the block and see if the alternator output is steady. Any variations or dropouts imply the alternator is not well. :laughing6-hehe:

Good luck,

Hockeypuck

[RED RUNNER]

RR,

If the switch-off current really is 3mA the battery should be able to provide this forever. Look at it this way: a typical motorcycle battery is rated at 12V, 12 to maybe 20 Ah. If the quiescent current is .003 A, a 14 Ah battery will supply this for 14/.003 = 4700 hours! In practice it doesn't really work this way but close enough. Overnight shouldn't be a problem and the 3mA sounds like trickle current being supplied to your ignition module. I would expect it to be somewhat higher, maybe 20 mA. There are a couple of things that I would do to diagnose the problem. First, go to Lowes, Home Depot, or whatever home improvement hyper-store you have in your area and buy a $10 analog multimeter. Sperry makes these for the chain stores and they are surprisingly useful. Repeat the switch-off current drain test using the cheap dial meter you just bought this way: Key off, remove one of the battery leads (doesn't matter which as long as you pay attention to polarity) and attach a meter lead to the loose battery lead ring. Then quickly tap the other meter lead to the battery post that the lead came from. If the current is really 3mA the meter needle will jump across the scale then settle back to around 3mA. The advantage to using an analog meter is the needle movement has inertia. Suddenly completing a circuit of significant ampacity doesn't make a dial meter go all goofy. Digitals are great but tend to be too quick. By the time you realize something bad is going on, the meter fuse has blown and you get to start over. I keep a cheap analog and a digital around for just this purpose. If it stays high then a parasitic drain exists-probably not a short-that is killing the battery. As one of the other posters said, it then becomes a fuse-pulling game.

Assuming that this test doesn't get you anywhere, I would suspect the alternator. Have you tested the output? It should be >=13.5 VDC regardless of load. This can be done in the driveway or use the cheap meter by taping it to your gas tank and running a couple of small leads to the battery top. Then you can ride the bike around the block and see if the alternator output is steady. Any variations or dropouts imply the alternator is not well. :pissed:

Good luck,

Hockeypuck

Thanks for the info. Your calculations were very informative. My meter is a cheapy with a sweep needle. When I did my test I recall the needle jumping and then settling down. I'm going to try it one more time. I may pick up another meter to make sure mine isn't messed up.

If the battery drained very quickly (overnight), without me having run the bike more than ten minutes, would the stator or alternator be a factor at this point? Regardless, with all the problems with stators I've been seeing, I am very curious as to my output.

[turtlecreek]

dang SV guys....stealing all the lime light :)

once battery is charged, check voltage (12.8V)

let sit over night.....still should read the same....

put in bike and connect

turn on bike

at idle 13.5V across battery terminals

rev to 5000 RPM....14+V across terminals...i think 14.8V is right but not more than 15.xV

let us know what you read.

depending on these readings, we'll know more about your RR/stator circuit.

[hockeypuck]

Red,

The stator is part of the alternator. There are three main components in an alternator: rotor, stator and regulator/rectifier assembly. The rotor may be a permanent magnet or require excitation from the regulator circuit to become magnetic. Most auto/motorcycle alternators are of this latter type. The stator is the shell of varnished wire loops and iron lamination that surrounds the rotor. Alternating electrical current flows in the stator wires as a result of 2 conditions, the first being a spinning magnetized rotor while the second is the presence of a suitable load. The regulator/rectifier performs two functions, as the name implies. The regulator circuit uses a closed loop feedback technique to properly stimulate the rotor field across a wide span of engine revs such that the alternator output voltage is held nearly constant despite speed and load variations. The rectifier uses 4 (or more) diodes to derive DC current from the AC that all alternators and generators actually create.

The weakness that many motorcycle alternators suffer from is weight or rather the lack of it. A robust alternator tends to be a heavy, space-eating lump. Motorcycle engine designers have pared the alternator down to the smallest size possible. This usually means little mass in which to dissipate heat and worse yet, smaller conductors in the stator windings. These overheat and break down the insulating varnish coat causing a shorted stator condition. This problem seems to be more fashionable in recent years moreso than the once-common fried regulator. Rotors, on the other hand, never fail. As long as the end bearings survive (forever I think) the rotor should be fine.

There are a couple of ways to test for a baked stator. Obviously, if there is no output at the battery the stator is near the top of the suspect list. Check for cut leads coming out of the stator housing, fuses in these leads, or damaged connectors. The path from the alternator to the battery is usually pretty direct so this shouldn't be too difficult. It may also be possible to open the connector nearest the alternator and put your voltmeter across the output leads here. Start the bike and check the output voltage. It should be at least 13.5 and probably higher since your meter represents no load. Keep in mind that the rest of the bikes electrics will be running off the battery so don't leave it on for long! If you do get a solid +13.5 VDC here then I would start looking a little harder at the wiring between alternator and battery. Last, there is always the Sniff Test. A shorted stator will sometimes suffer enough that the varnish burns giving off a pretty nasty stink. You will have to open it up to check for this but it may prove interesting. Good luck.

Hockeypuck

[VFRSuperfreak]

I'm having this same issue, it seems. After having the stator rewound, my new Yuasa is having trouble starting the engine, and has now twice left me stranded.

Recap;

I bought this battery back in December, it didn't fix the no-start problem, and on the advice of the Honda mechanic (who gave a very superficial check on the problem), I had the stator redone. I have since bought a new R-R, albeit not the best brand avail.

I made a post about all this back then.

I came to this post because I was looking for some background info on parasitic discharge, so I went and tested this. It was a pain because when I reconnect the batt loop (with multimeter in between the + post), the alarm has to do its thing, which draws some 3amps for a second, then settles down).

And the meter settled on this; 137maH. Checking this and other posts, this seems to be on th high side by some 120maH !. No? . I have a presence alarm, and few weeks before getting the new battery, I had to replace its indicator led light, and I believe I was careful enough to get a low-drain one as before.

This doesn't mean that's the only suspect, as I haven't done a fuse-pulling session to check on this 137maH drain with key off.

I'll update the linked thread. Just wanted to say not sure which thread to continue on. Thanks!

[Vee-Ef-Ar]

I'd continue on the linked thread, as 3 people are following that, and none on this one.

When checking the leak test, don't you need to test on the - (neg) side?

[Bassie]

What if you bought a bad battery? It happens.

[Switchblade]

+1 old battery.