Parasitic drain and battery query.

[NotSoLilCrippseys]

Hi. I've done some scouring of the forums before posting. Please be gentle.

Here's where I'm at:
ST1100, 1992, with the 40 amp upgrade done about a year ago. 70k+. I've had the bike for just under a year and about 5k. PO did the alternator job. She's been reliable as can be - until about 2 weeks ago or so. Battery is AGM and manufactured 12/21. Never had dead battery issues with it before a few weeks ago.

What's not bone stock, at least that I'm aware of?

• 40 amp alternator upgrade
• LED headlight kit
• On board voltmeter (switched power)
• Bypassed thermostat fan switch for manual control at bars, mainly because fan switch failed and I have yet to swap in a new one.

I have not started ripping too far into things - yet. What'd I do so far?

• Considered maybe ignition switch has something going on, as I read some threads suggesting this issue the other day. Disconnected battery, doused internals with electronic parts cleaner, worked key back and forth 40 times, etc. Hooked battery up. I have yet to unplug ignition and clean contacts. Maybe there's something to ignition drain while off?
• Tested for power at fan switch just because. Nothing with the bike off and battery connected.
• Pulled all wires associated with aftermarket usb/voltmeter running directly to battery - even though it has an off switch.

I'm seeing the following from this thread:

• Load test the battery. This seems like a reasonable move, as they can go bad. I've not done that yet, probably the easiest thing to try.
• Test for the parasitic drain with the following method: "Once you get your battery sorted use a DMM set to measure current (Amps) in a low range and connect it in series with a battery lead." I'm not sure what a DMM set is, probably because I have too many other acronyms floating in my head. I've got a multimeter with probes and a digital readout - is that the DMM?
• Alternator diode may have failed. (I hope not!) Is that internal to the alternator, which would mean I'd need to clear shop space and move my project bike for a major operation? Or is the diode hanging off the side of the bike somewhere under some plastic? Also, I do get charging while running - 2 voltmeters show it, one switched and one directly on the battery, and my multimeter confirms it all. Would diode failure mean parasitic drain while off but charging while on?

Thanks in advance!

So here's the longer story with appropriate drama for those interested in such things:

I recently added an old trickle charger pigtail to the battery to help keep things topped off, as we had a recurring bout of the bad weather in Maine, and it's a pain to pull plastic just to trickle charge. I ride year round - as long as the roads aren't snow/ice covered. But I hadn't hooked up the charger. (dumb.) Soon, I found a dead battery. Easy: cold, under my CycleShell, no ridie, no startie. I charged her up and rode her. All seemed normal.

Storm happens. Two days later, I go out to start her for the morning commute. I'm down to 6.5 volts. Damn. Off come the plastics, on goes the jumper. Start, warm up, ride to work and back.

My onboard led voltmeter usually reports about 13/13.5 volts while running - though yesterday it was down in the 12s, odd. A second voltmeter with USB ports running directly from the battery is always a bit higher.

Dead again after a couple days. I pulled the trickle pigtail, as it was the "new thing" on the bike. (Maybe there was some funky thing in there?). I recharged and rode.

Two days later, after not riding, dead again. So I pulled the fuse from my second voltmeter thinking perhaps I'm getting parasitic draw from those USB ports - even though it's turned off at the voltmeter/usb switch. The bike was apparently still drawing power while off. (and probably not just that lcd clock)

I removed the leads running from the voltmeter to the battery to really eliminate that possibility.

What wires are there on the battery, you ask? Negative lead; Positive lead; and a red wire coming from a Fuse block to the positive lead. (I think that wire runs from the alternator over to charge the battery, as removing it gave me 0 volts on my onboard voltmeter. Hooking it up gave me 13.5.) That fuse block sits just to the left of the battery (when facing it), and it's not the one that sits to the right of the battery and a little above it.

This is about my 9th bike, but there's a bit more to this baby than what I'm accustomed to. My newest ride before the '92 ST was an '84. Mostly, I wrench and ride late '70s and early '80s Hondas.

 

[Sadlsor]

Until the wiser electrons / neutrons gadget guys get here, this is my concern when you say, "I'm down to 6.5 volts." That's like DEAD battery territory, right there.
A lot of batteries don't ever fully recover from that; my question would be "how OLD is your current battery?"

 

[SMSW]

You got the right poop in your things to do list. Yes, load checking the battery is easy and usually free. Charge it up and take it to your favorite service station.

A few points to consider. Nobody can tell you how long any given light bulb or battery will last - their lifetimes are averages of hundreds (thousands(?) of samples. Once a lead acid battery goes dead, it tends to shed some lead from the plates and this stuff may short out a cell or contribute to low voltage. Repeated discharges may cause more physical damage to the battery. However, AGM batts are more resistant to this than flooded batteries. A load test will tell you the condition of yours.

It sure sounds to me like a parasitic drain. Wait til you get the results from your load test, if the battery is good, then start looking for said leakage current. A DDM is a digital mult meter - what you have. You will have to put it on a low range and install it in series with the battery. You are looking for low current draw. Most DDM's do not like large currents when measuring amps - I had one that was fused internally for 3 amps - and I stupidly blew that fuse. Different instruments will have different fuses (maybe - some do not) but if there is no fuse (usually cheap DMM's) you stand a good chance of frying the meter with a large current.

The voltmeters we use on our bikes (the small one that I think you are talking about) are cheap gadgets and I would expect different voltage readings from different samples of the same brand. I get different voltages when measuring with my Greenlee DMM or with my Fluke - and the latter cost me $700 and comes with a long treatise on how fine it is and a pedigree that rivals those found in the Westminster Kennel dog show. These differences are only a tenth or few tenths of a volt but the two meters rarely agree perfectly when used side by side.

USB ports draw a bit of current 24/7 but yours are switched so that should not be an issue. If your onboard voltmeter was showing in the low 12's when running, I think there is something wrong with your charging system. I no longer have an ST, but both my VStrom and old Guzzi will show voltages increasing with rpm's from idle up to a certain point - then constant voltage (usually in the low 13's) as revs continue to build.

Edit: The charging pigtail should not be an issue unless the insulation on it is old, cracked, and peeling off in chunks. You should get rid of the trickle charger - they can cook a battery if left on too long (not saying you did this) but pick up a smart charger (Accumate or Battery Tender are two good brands). They not only will charge your battery, they will maintain it and most even have a sulfate be gone cycle (pulsing voltage to break up the lead sulfate that forms on the plates).

 

[NotSoLilCrippseys]

Thanks.

6.5 volts is dead territory, for sure. Maybe that cold spell and deep discharge really damaged the battery a few weeks back.

I have a battery tender, which I referred to as a trickle charger. I don't keep it on all the time - mostly, I rotate the two I have across about a half dozen bike batteries while they're in winter storage. Tend, move on, tend, move on.

I thought the 12v readout was messed up Monday on the ride back from work. First time ever on that. It was 13.5/6 today after I started up the bike and before I posted this thread up.

I'll report back once I've load tested the battery at my local Napa. That'll be a start I probably should have done before even posting.

Tonight, she'll sit on my Noco Genius tender, which is supposed to also repair batteries.

After the number of times I've pulled off the side panel and futzed around on this issue, I'd welcome a discovery that I just need a new battery.

 

[kiltman]

I have a 2002 and have LED headlights and my voltage at idle reads 14.1-14.3, with regular headlights it will drop down to the 13.9 volts.
I’m wondering what your voltage reading is immediately after a bit of a ride and the bike turned off. Is it in the 12.1-12.4 range? Or is it less than that if so by how much?
Check the red wire to the main relay, Is it good condition?

 

[NotSoLilCrippseys]

Kiltman.

Voltage on my wired-to-battery meter reads about 14 or so when running; the switched voltmeter is always a bit lower on readout - about 13.5/6. It will fluctuate a bit, but I don't stare at it while riding down the road. Voltage gets to 13.5+ (or 14 on the other meter) at idle. I did check voltage after a recent ride after this problem surfaced, and the battery was reading over 12v (with my hand-held multimeter). I had thought it was just a weird "dead battery" thing that would go away. I'm not draining the battery while riding - or not yet (I write as I make an offering to the appropriate gods).

Here's hoping it's just the battery. We did have a -25 F deep freeze in February that coincided with a couple weeks when I neither rode nor charged the battery. (3 of my house's pipes burst, and that's not happened before.)

 

[NotSoLilCrippseys]

OK.

So low 14s at the battery while running. I can check that again - and with a handheld. I think that's about what I have.

A voltmeter on the bike that IS wired to the battery will read 14/14.1/14.2 with the bike running, while the one wired in somewhere else (it's switched) always reads lower (13.5 or 13.6).

If I need to pull the bike off the road for charging diagnosis work, I'll be bummed. Of course, there's nothing like getting shoulder deep in a bike to get you to know its inner workings. (Usually, when I do that, I've bought a basket case. This bike was definitely not that.)

I'll load test before I freak out any more.

 

[Larry Fine]

Everything you have posted says it's the battery. Is it still under warranty, even if prorated?

 

[Sunday Rider]

What if you disconnect the positive wire from the battery after a long ride and testing to see if the battery drains again?

 

[SMSW]

Just an idea. After dealing with a dead battery at an STOC event, I installed a couple of heavy wires from the battery to the area under the seat. I insulated the ends with vinyl tubing (the wire was #6 welding cable, each about 18" long, one painted red, one black) and taped the tubing on for good measure. These are to jump the battery should I need to again. It is easier taking off the seat to get to these 'jump wires' than pulling the side panel.

 

[Larry Fine]

You really only need to extend the positive if you already have a good chassis ground point available.

 

[jfheath]

I would guess that DMM = Digital Multimeter ?

It sounds like you know what to do. Except. ... Don't assume anything. Be methodical.
eg don't assume that the battery is Ok. Its a newish battery, but that reveals that it might have needed one because there was a problem before it was replaced. A battery drain that leaves a battery with no charge for a long time isn't going to do the battery any good. So if you load test the battery and that proves the battery is duff, don't assume that putting in a new battery is the whole solution.

Disconnect the earth to the battery and measure the voltage flow and current flow between the ring terminal and the battery. Clean the ring terminal first. Find where the harness connects to the frame - disconnect it, clean the massive copper connector, shiny bright, clean the frame, bare metal. Dilectric grease is a good idea, but Reconnect. At some point you will need to grease all around this to protect it.

Beyond here, I am talking theoretically. I owned 2 ST1100s, but my oldest was a 1996, so experience with your electrics is non existent. And my memory isn't good enough to remember much of the stuff that I knew about the 1100. Hell, my memory isn't good enough to remember what I had for breakfast most days. So I am just describing what I would do.

But start pulling fuses, one at a time. Start with the one that feeds the clock. In theory there should be zero flow after that, but there are a lot of wires that remain live when ignition is turned off. Terminals will have got wet, may have corroded and you get a weak conductor between pairs of terminals. Pulling fuses one at a time and will help to determine where the problem is likely to be. If the meter shows no flow after pulling a fuse, then whatever circuit you have just disconnected is likely to contain the problem.

Treat any added connections to the battery with suspicion. Eliminate those first. You'd have to check whether that red wire is normal.

Beware this approach with a multimeter. Anything that is turned on will be demanding a relatively large current flow, and all of that current will go through your multimeter. If it is a large flow eg more than an amp or two, your multimeter cannot handle it, and will probably blow an internal fuse. Rather than a multimeter, use a 12v light bulb to show any flow.

Get a circuit diagram. Find out whether the ignition switch has a fuse between it and the battery other than the main 60A ? strip fuse near the battery. I think, but don't know, that the ignition switch is always live and feeds the fuse box, once it is turned on.

If after a while you discover that the problem has gone away and you are getting no flow between negative terminal and the battery post. Don't assume that you have fixed it. Recharge your battery and try again later !

 

[Tenmilsocket]

The service manual has the procedure and values for a leak test. I had a 3rd Gen Magna with a key off leak and the starter solenoid/main fuse assembly was the culprit.

 

[Larry Fine]

To reiterate: When checking drain current, do not turn the key on!

 

[NotSoLilCrippseys]

This is going to be a status report in fits and starts. I'm being tentative with the battery.

• Tender signaled full charge this AM. Multimeter showed about 12.85 volts. I started the bike, and I had 14.1 at the terminals.
• I rode the bike to work, disconnected the battery, then reconnected to ride home. Basically, I didn't want to have to bump start if I could avoid it. I also parked on a hill in the event that became necessary.
• Riding home was fine/uneventful. Battery reported 12.85 at the terminals after stopping, using the multimeter. Seems to be charging while running.
• I pulled the battery and drove to Napa, where their load test showed a good battery.
• At home, I installed the battery and put the tender back on for the night.

One thought is that perhaps the battery suffered some bad discharge about a month ago (-25 degrees, no recharge, no ride for a bit). Maybe my tender/repairer did some service to it. (And maybe I'm full of boloney thinking glass-half-full thoughts.)

It turns out my multimeter is too basic and lacks an amp setting. I've ordered another to do the leak test Tenmilsocket shared on Wednesday. (BTW, are you the one with my missing 10 mil socket?) I won't be able to do that test for a few days.

In the meantime, I'm thinking I want to be a bit tentative. I'm riding without a side panel.

 

[dwalby]

It turns out my multimeter is too basic and lacks an amp setting.

can you post a picture of it please. Even the $5 give-away meters at Harbor Freight have an amp setting, so I'm surprised to hear you have one that doesn't.

 

[kiltman]

Is it possible that the terminals to the battery weren’t tight when you started having problems. (You wouldn’t be the first, I believe I have been guilty of this)
Now that you’re disconnecting and reconnecting it you might be more conscious of making sure that the connections are tight. This could explain the battery now charging properly.

 

[Tenmilsocket]

I had the luxury of starting with a brand new battery so I didn't have to worry about that. On the Magna, the max key off drain is supposed to be 0.01 mA and I was measuring 52 mA. That was enough to kill the battery after 2 or 3 days. I got this from Northern Tools on sale for $12 and it worked fine:

https://www.northerntool.com/products/ironton-digital-pocket-multimeter-6-functions-43981?cm_mmc=Google-LIA&utm_source=Google_LIA&utm_medium=Electrical > Electrical Testing Equipment > Multimeters&utm_campaign=Ironton&utm_content=43981&ogmap=SHP|LIA|GOOG|STND|c|SITEWIDE|||||856744531|42214684743&gclid=CjwKCAjw_MqgBhAGEiwAnYOAeoq56upDQ4p9AZbqJgZTj3_byL7PBVV7eVR8dQ27fa0tH4VycwJm-hoCL_YQAvD_BwE&gclsrc=aw.ds

No, I do not have your 10 mil socket, that one is mine!

 

[NotSoLilCrippseys]

I'll report out again over the coming day(s).

On the multimeter, it's a Gardner Bender GDT-311, no AMP option. https://www.gardnerbender.com/en/p/GDT-311/Gardner-Bender-GDT-311-Digital

Weird, I know. I think I must have been in need of a tester to replace a defunct Craftsman and grabbed a cheap one without looking at it too closely. It was a couple years ago.

 

[SMSW]

On the multimeter, it's a Gardner Bender GDT-311, no AMP option....

I'm a retired eledtrician - mostly residential, commercial, and occasionally industrial. In 40+ years, I never needed the milliamp function. Sure, I used a clip on ammeter regularly, and the other scales, but except for once wanting to use it to check a thermocouple on an old furnace, I never needed that scale. On that occasion, i decided fooling w/ a few dollars worth of t-couple was not worth it and just replaced the thing. That fixed the furnace.