Charging issues (not R/R)

The bike seems to have picked up some charging issues. It was fine for the last 4 months, and then died on me on Friday, stalling as I was pulling away from a stop-sign. Not enough juice in the battery to turn over the starter.

Following the oft-linked PDF for charging issues, I came up with some very borderline-ok results, and wanted to get some feedback on them.

I put the battery on the charger last night, and charged up to full, but didn't test it then. This evening after work, the charger rated it at 70% full (Schumacher SC-12000 just plugged it in and had it read me the voltage and load test it).

I started on the test anyway, knowing I might have skewed results (70% is often "fully charged" on some cars, and I'm not familiar with how well this bike charges the battery.

Voltage was low, but only a little. 13.8 or so at idle. 13.2 at 2500 rpm, 13.0 at 5000rpm (not the direction I expected at all).

I proceeded through the testing, and tested the RR in isolation just to be sure, and it's fine (0.45 V across each diode, in the correct directions).

The stator seems marginal. Getting a solid reading from the DMM was difficult, anywhere from 0.4 to 0.6 Ohms across each of the stator wires. This was listed as on the low-side of normal.

Due to it being late, and the bike in a friend's garage with an HOA that frowns on vehicle maintenance, I couldn't retest the stator at 5000rpm to check for 50V. I'll do that tomorrow, now that the battery is fully charged.

The battery is definitely unhappy, as well. I kicked the charger over to high-amp mode, and it decided to go into desulfation, and performed desulfation on the battery for a while, then charged it up (at a more reasonable rate than how quickly it was charging yesterday).

So does this look like just a marginal battery and a marginal (but servicable, for now) stator?

Bike is an '86 VF700, 17K miles on it. I'm third owner, and know the previous, who knows the original (been passed through a few friends since it was bought new). Not raced, not ridden especially hard, dropped twice on left side (35mph and 0mph). Since I bought it in December, I've put maybe 200 miles on it, although all at lower rpms (maybe over 5K up to 7k a dozen times). I try to keep it in the 3-4K rpm range when riding about, which I fear is a bit low (but the supertrapps make it sound like it's screaming at 5K+).

It had been parked for a couple years, seeing almost no riding (17K in 21 years isn't much riding, period).

So, if it's the stator, buy the Clymer or the Honda manuals, or both (and see which each has to say about it?). With cars, I know nothing touches the factory service manuals, but they're appropriately expensive (my Dodge Ram's manual cost $120).

 

I would not rule out the R/R, IMO. I had a bad one and for a while it showed as good when I did the tests. In fact, my voltages were 13.5 at idle, 14.5 - 6 and 2 - 3k RPM, and above that back to 13.5 volts. Turned out to be the r/r. Make sure the battery has a full charge (12.8 volts). The voltages you described could be from a bad R/R. Check the connector where the stator wires connect to the r/r. On my 93, it is behind the right side panel and it is a 3 prong connector with 3 yellow wires ot make sure none are burnt or melted. Yours is probably in a different location, but I would venture to say the wiring is similar. When checking the stator, the voltage should rise steadily to I think a max of about 70 volts. If the voltage drops off during the increase in rpm, then the stator is probably bad. Best case, the battery is bad and you need a new one. Worst case, stator is shot and you need a new one. In the worst case, you may want to replace the r/r while your at it, just for insurance. http://www.ricksmotorsportelectrics.com is a good place to deal with. I got a stator and an r/r from them. The r/r is a thicker unit than the OEM. I relocated mine to under the subframe.

 

Did some more poking around today, starting with a fully charged battery. First thing I noticed is that it started without turning over a couple times first. It's been slow to start (I assumed it was just due to being a cold, carb'd motor).

I checked the stator first, in isolation (without RR hooked up). 20+ volts at idle, and up to 100V with revs up to 7K. Anything higher than that and I'd be deaf from the supertrapps (and the neighbors would kill me).

I hooked up the RR, and rechecked, and confirmed about the same voltages as before. As high as 14VDC at idle, 13.0 at 2500, and rock solid there all the way up to 7K.

I hooked it back up the battery, and same as before.

Now, the battery is another story.

I fully charged the battery (12.8-12.9V) using my charger, and then started the bike, ran it for a few seconds, shut it off. Restarted bike, ran it for maybe 2-3 minutes, revving it up to 5-7K twice. Shut off bike. Battery was dead. Couldn't restart the bike again.

Charger said the battery was 50% charged or so. I put it on 12Amp charge, and it immediately went into desulfation mode again. It sat and cranked on the battery hard for a while, and brought it up to 70ish, and I restarted the bike (with the charging system fully hooked up). Ran the bike for a few minutes, and then shut it down. Checked the battery voltage. 13.2V or so.

Hooked up the charger, and it said 100% charged. Left it hooked up. As it sat, it worked down slowly to 79% charged over the course of 15 minutes or so, with the bike fully off.

I disconnected the battery, put the DMM in series with it, and measured 380uA of current draw through the bike. Small enough that it's negligible (about a thousand hours of power from a AA battery at that low of a current draw).

With the charger hooked up in monitor mode, I watched the battery just slowly self-discharge down to 79%, where it was down about 1V from where it was right after I shut off the bike. I expect the next time that I go down to start it, it won't start, unless it's fresh off the charger.

Maybe due to the small size of the battery, and having to run the headlight as well as the dash and ignition it normally drains down that fast, but it seems like the battery has little to no capacity (granted, these batteries are tiny compared to a car battery).

My current plan is to pick up a new battery, and see if that fixes the problem.

 

Ok, I am a bit confused so please bear with me. At idle, your voltage was as high as 14. From 2500 on up it was 13? From 2500 on up did it go above 13? I ask because "rock solid" leaves a lot to be interpreted. A local dealer service guy told me that as long as it was charging at at least 13.5 volts it was good to go. I can live with that, but it does not do anything to restore my faith in it not leaving me stranded somewhere. I would have to venture, seeing as you "appear" to have a similar problem that I had, that the r/r is gone and needs to be replaced. But to really cement that, I would need to know the numbers from 2500 to 5000 RPM. I am not ruling out a faulty battery, but I am still leaning to the r/r. Oh, btw, a faulty r/r can ruin a good battery, too, or so I have heard.

 

Yeah, it seems odd.

13.5 to 14.0V at idle (say from 600-1500rpm, it was still idling high from a cold start and the choke half on).

Then as soon as I cracked open the throttle to run it higher, it drops to 13.0V, from 2500-5000-7000rpm the meter read 13.0V the entire time.

I wish I knew what the circuit was in the RR, clearly it's at least 4 diodes for the rectifier, but I'm guessing the regulator is actually a big honking set of zeners that limit the voltage (and burn off the excess power as heat). Honda wouldn't have this problem if they didn't use a permanent magnet stator, but one based on an electromagnet.

I found in reading last night that the "older" style RRs appear to have drifted up in voltage as the revs climbed, but that the later model ones were higher at idle, and the same voltage at all revs above idle. Which matches what mine's doing. No idea if it's original or not.

From your pics in this thread: http://vfrworld.com/forums/maintenance/7271-r-r-replacement.html

Mine is very similar to your old RR, same shape, but mine has fins on both sides, and the connector is replaced with a grommet with all the wires coming out of it to a pair of pigtails. So very similar, but not quite. It's bolted to the inside of the subframe just below the seat, in a place of 0 airflow, and bolted to metal that gets pretty warm from the engine (my bike's frame is often too hot to touch with bare skin, which I wonder if is another problem).

Following through the PDF, everything isn't quite ok, but it's really close to OK, but the battery is unknown, so I'm going to replace it, and see where it's at.

Working through the PDF for testing the system, I get 13.0V instead of 13.5V across the battery when charging with revs above idle. The RR tests out perfectly with a diode tester, 0.45 V across each diode. The stator windings test at 0.4-0.6 Ohms, depending on how good of a connection I can make to the tabs in the connector. The backside of the stator connector was disgusting, covered in chain oil and road grime, enough to be conductive, especially at the higher voltages that can come off a stator.

So, new battery, and then a full retest, and then I'll get it home, and decide if I'm just going to replace the charging system completely and be done with it. I just *REALLY* do't want to drop $200 on a RR right now without knowing if this one is good or not. I might take it with me to see if the dealer does any better tests than the PDF has. But I doubt that they'd have something that replicates the power production of the stator, and verifies that it works correctly with a load on it (something that's hard to do with a DMM).

I also think a voltage meter of sorts is in my near future.

 

Yeah, my old one tested ok. I fixed teh link to Rick's Motorsports in one of my previous posts. My old r/r was replaced before I bought the bike, so I do not konw if it was an Honda unit or not. The Rick's unit cost only about $120 plus shipping. Rick's shows the a price of $105 for an r/r for your bike, Rick's part number: 10-122. I agree, the battery is the least expensive component to start with, too.

 

ok first when doing any kind of charging test you need a good, fully charged battery. also you should always charge a motorcycle battery at 1/10th its amp hour rating(ie. a 16 amp hour battery at 1.6 amps or round to 2 amps). never use the quick charge as it will just shorten the batterys life and it won't fully charge it, and the battery will never fully charge back up again! second your charging system should stay above 13.5vdc, especially when the rev's go up. sounds like the regulator is going bad which is part of the r/r unit. but first i would get a new battery and retest. charging systems are very simple you have a stator, a r/r and your battery. you sound like your on the right path with testing. good luck

 

The new battery (Yausa) is in the car, I'll drop it in this evening and see what I get.

Running on battery alone, how much should a full battery get me? Running for how many minutes, or how many start attempts?

btw, flooded cell batteries are a PITA. I'm used to sealed, non-servicable batteries, and prefer gell-cells if I can get them (roughly indestructible). The Optima in my truck was just amazing (well, for a battery).

 

ok not really following on the "Running on battery alone, how much should a full battery get me? Running for how many minutes, or how many start attempts?" but a full charged battery will read between 12.6 and 13.2VDC and under load(starter turning) no less then 10.5VDC. as far as run time on battery alone, hard to say but should be fine for the time needed to test the stator. thou i wouldn't run it to long (maybe no more then ten minutes at a shot) cause your headlight takes a lot of amps. and start attemps, well as long as you don't keep repeatilly cranking on it(heating up the starter and wiring and draining the battery without letting it "recover") shouldn't be a real problem. you said you tested the diodes so the rectifier should be good you said. diodes should be .3-.8VDC foward bias and OFL reverse bias. 6 diodes 3 postive 3 negative. also when testing the stator did you test it loaded(pluged in and probing the connector) the best way when possible it should read about 9 to 20 VAC at idle. or unloaded(unplugged) should be about 15-100 VAC at idle. also you can check the resistance of the stator(unplugged not running) about .2-2.5 ohms. with a OFL to ground.

 

What I was hoping for was a sanity check on how long a bike without a charging system would run off just the battery (not going to go riding if the RR turns out dead, although it doesn't appear to be so).

RR reads 0.45 V forward across all the diodes, and open-loop reverse, just like it should. Stator is 0.4 Ohms across each winding. Unloaded, I was seeing 25V from the stator at idle, and 100V+ running up and over 5K rpm.

The new battery is in the garage with the bike, but I won't be able to get to retesting the running voltages with the new battery until this weekend (and hopefully it will check out ok enough to ride it the 30-35 miles home to my place where I can make all the noise I want (I'm semi in the country) vs. the friend's garage in a very residential area). It's about an hour to hour and a half drive depending on rate of travel...

 

well i still say your regulator took a dump. but hard to say without being thier myself. as far as driving it that far, i'd probaly give it a shot but i'm alittle on the reckless side. remember that if the battery drops below 10.5VDC your brain will shut off. leaving you again stranded. so keep a cell phone handed and a buddy with a pick up on stand by. there no junk yards around? can't get a cheap used on or borrow a buddys just to take the R/R out of the picture?

 

This is not a part I would trust to get from a junk or salvage yard. The odds are 50/50 of getting a good one. Go here to Ricks Motorsports Electrics. They have good prices and I have heard good things about them I ordered an r/r for my 93, had it shipped overnight and it was here by 7:30 AM the next day. The people at Ricks are nice people. Here is a pic of the old r/r and the Ricks model:

side by side:


Another side by side:


As you can see, the Ricks unit is beefier than the one I had adn I presume the old one was an OEM unit, tho I cannot say for sure as I am not the one who replaced it, the previous owner did. In the process of replacement, I also relocated it to the underside of the subframe. I did this for two reasons: 1) since the new unit is beefier, there would now be less space between it and the rear side cowl, which would result in poor heat disspation; and 2) the underside of the subframe is open to mass air. Here is a pic of the relocated unit:



Oh, I should note that I have bypassed my wiring harness completely. I ran 3 yellow wires (12 GA) to the stator connector, a black to ground (10GA), and a red to the (+) on the battery (also 10GA).

 

I saw that thread of yours where you first posted those pics. Your old RR is very similar to mine (likely same casting for the heat-sink). Do to positioning of mine, I probably can't put a larger unit in the same place as my current one.

Today the new battery goes in, and I take a look to see if it's actually charging or not (or if the RR falls over as soon as it has a load on it).

Just wish the bike was in my garage, and not an hour away.

 

I put in the new battery yesterday. Same exact voltages from the regulator as before, but I was able to confirm that the regulator *is* charging the battery.

The new battery was at 60% charge according to my charger after sitting for a day after being filled with acid. I swapped it for the old battery, and started the bike. It started near instantly (no turning over a few times before catching). I then managed to kill it with too little choke too fast, and had to restart it. It again started much more strongly than it had before.

I let it high-idle for a few minutes (2000 rpm, using the choke to keep it up there), and then checked the battery voltage. 12.6V, and 80% according to the charger.

I restarted the bike, and went out for a ride. Maybe a mile tops, just running around a residential and commercial area, running the revs up to 6-7K a few times.

Coming back, the voltage was up at 12.7-8 or so, and the charger read 90% for the charge on the battery.

When I go by today again, I'll check the old battery, but when I left it (full to the marks with acid, so not a dry battery), it was charging up, but it was self-discharging at a rather rapid rate (from 100% charged to 79% charged in 10-15 minutes, with the bike turned off, and a parasitic load of 0.000380 amps).

I think I'm going to order a new regulator, just to be sure. And I'm certainly going to be picking up a voltage meter.

 

Rode the bike home yesterday, starting with a 12.7V battery (just where the acid brought the battery up to after being filled). Bike started without issue (4-5 times in half an hour, actually, due to the seat keep coming loose after getting the bike started, which is an entirely different topic). Road the bike 35 miles home, and after it had been in the garage and parked for about half an hour (off), voltage was 12.73.

It's definitely acting like it's charging, but we'll see. I picked up a Battery Tender Plus and a votage meter today (Kury something or other). Those will go on tonight.

 

I like the Kuryakin volt meter. I had on e on my 86 Radian and now have on on my vfr, too. Keep us posted on this. :thum:

 

Haven't put on the Kuryakin meter yet, waiting for a service manual to arrive so I can more easily locate a good circuit to attach it to.

I have, in the meantime, ridden it a fair bit, and installed leads for the battery tender. The tender always wants to top off the battery after a ride, so I'm pretty sure that something isn't quite right, still. I'll probably do the RR just to be safe, as I plan to soon start commuting 36miles each way on this bike.