Parasitic drain

[desmo900]

Hello all, it's been a while........ I recently replaced the battery (new Yuasa) on my '07 big girl because it was old and the battery would not crank so I figured it was time for a new battery. Installed new battery, rode for about 8 hrs with 3 or 4 stops. Bike cranked and ran fine each stint. Bike sat in garage for 2 weeks. Attempted to ride, and the bike wouldn't crank, horn would barely blow, basically indicating what you'd think would be a nearly dead battery. I figured there was a sudden dead short or something that was draining the battery when not in use. Here are the steps I took to diagnose:

Freshly charged battery. Showed 12.1v with voltmeter.

Disconnected negative battery lead and put a voltmeter between the negative battery terminal and the negative battery lead. Key was off. There was almost 12v drawing across the lug and the cable.

I removed every accessory fuse one at a time and re-checked result between battery lug and cable. Still a 12v draw with each fuse out one at a time.

Removed 30amp main fuse and re-checked. Still a 12v draw.

Re-connected battery. Turned key to on position and placed voltmeter on positive and negative battery lugs. Meter only shows 7.3v. When I pressed starter button, the voltage actually went UP .5v but trying accessories such as horn, windscreen, etc dropped the voltage about .5v.

The only accessory on the bike is factory heated grips, which were installed when the bike was new. I'm freshly charging the battery again and am going to bring it to a local Autozone for a complimentary load check, but even if they were to tell me that the new battery is bad, I still don't think that would explain a 12v parasitic draw between the negative battery terminal and the negative cable if the key is off.

Wondering if the collective consciousness has any thoughts on this? Thanks!

Steve

 

[Obo]

The clock draws power all the time... not that it's much, but it's still a draw.

They way you were measuring, putting your meter between the neg battery terminal and the neg lead, you should be getting 12v. You're measuring the voltage, not the load.

Once you take off the negative wire and put your meter between it and the battery negative, your meter "sees" the negative wire as the feed coming from the + side of the battery.

 

[DannoXYZ]

Yup, here's how to measure for flow when everything's off. For different bike, but same procedure.
You want to measure amps flowing, not voltage. Start with 10a range, typically need to move ground-probe to "10a" socket.

What do you measure?

 

[Sadlsor]

I know with certainty Garmin has made some GPSs with a constant / parasitic drain, the lovely and discontinued 476C being one.
Even then, however, the drain would not be 12v.

 

[Obo]

I know with certainty Garmin has made some GPSs with a constant / parasitic drain, the lovely and discontinued 476C being one.
Even then, however, the drain would not be 12v.

A 12v device always measures 12v. (Well unless you've got some shoddy connections....)

How much current (amps) it draws is different

The OP is measuring voltage in his method, not current.

 

[Sadlsor]

A 12v device always measures 12v. (Well unless you've got some shoddy connections....)

Fair enough. And the GPS should be about a 5amp draw, give or take.
I DO know that it can suck the life out of a bike battery in a few days, if the bike is unridden in that time.

 

[dwalby]

Freshly charged battery. Showed 12.1v with voltmeter.

Re-connected battery. Turned key to on position and placed voltmeter on positive and negative battery lugs. Meter only shows 7.3v. When I pressed starter button, the voltage actually went UP .5v but trying accessories such as horn, windscreen, etc dropped the voltage about .5v.

if your battery was freshly charged to 12.1v, and then it drops to 7.3v with the key on, your battery isn't fully charged to begin with. It sounds like you're placing the meter leads directly on the battery terminals, so you're measuring voltage at the battery source and not somewhere that could encounter an IR voltage drop, so that says the battery is suspect before going any further.

If the battery is fully charged, it should be closer to 12.6-12.7v, so the 12.1v is also suspect. Put the battery back on a charger and get it fully charged.

Your incorrect technique for measuring parasitic current draw has already been discussed, follow the procedure described by Danno after the battery is fully charged. However, the 0.1mA max leakage current figure doesn't apply, its for a different bike. I'm not sure what the value is for a 1300, but for the 1100 a couple mA is acceptable.

 

[Andrew Shadow]

However, the 0.1mA max leakage current figure doesn't apply, its for a different bike. I'm not sure what the value is for a 1300, but for the 1100 a couple mA is acceptable.

2.5 ma max per Honda service manual.

 

[desmo900]

Thanks to everyone for your replies. Good news. Bike is running and things appear normal. As per advice from various members, these were the steps I took to get where I am.

Get rid of old Yuasa smart charger
Put the good old Battery Tender on the bike for 12 hrs
Results:

12.2 volts across the battery with all cables connected and key off
Bike started and ran normally
14.2 volts across the battery with the engine idling

Removed negative battery cable again, and with key off observed the following results:

With meter set on milliamps and spanning negative battery terminal to negative battery lead, there was virtually zero draw from the bike.
Re-installed all cables and bodywork. I'm going to do a local shakedown ride with a couple of stops and then let the bike sit for 4 or 5 days and then re-check battery state.

As unlikely as it may be, it seems that the Yuasa charger may not have been adequately charging the battery. If everything is still good, with proper voltage still remaining in the battery and the bike starts normally after the 4-5 day rest period, then I'm pretty confident I'm in good shape. Does this reasoning seem sound?

 

[Andrew Shadow]

With meter set on milliamps and spanning negative battery terminal to negative battery lead, there was virtually zero draw from the bike.

This seems odd, unless you clock is no longer working there should always be a minimal drain.

As unlikely as it may be, it seems that the Yuasa charger may not have been adequately charging the battery.

How long was the motorcycle left unused before the drained battery presented itself. If it was a short time, unless the battery charger is defective and was actually draining the battery, this doesn't make sense either. The motorcycle's charging system should keep the battery fully charged without the need for an external charger if there is no parasitic drain. Leaving the motorcycle unused for several weeks will not drain the battery to the point that it can not start the motorcycle if there is no drain.

 

[dduelin]

12.2v directly on the terminals key off and disconnected is a battery 25% charged. Depending on the Deltrans model a tender will not usually bring a <25% charged battery to full charge. They maintain nearly charged batteries not charge up deeply discharged ones. Can you find a way to put a 1.2 to 2 amp three or 4 step charger on the battery for a full charge cycle before further testing for problems? Unfortunately a percentage of new batteries are duds out of the box and you really need a known good battery to diagnose troubles.

 

[DannoXYZ]

With meter set on milliamps and spanning negative battery terminal to negative battery lead, there was virtually zero draw from the bike.
Re-installed all cables and bodywork. I'm going to do a local shakedown ride with a couple of stops and then let the bike sit for 4 or 5 days and then re-check battery state.

As unlikely as it may be, it seems that the Yuasa charger may not have been adequately charging the battery. If everything is still good, with proper voltage still remaining in the battery and the bike starts normally after the 4-5 day rest period, then I'm pretty confident I'm in good shape. Does this reasoning seem sound?

Good job!

So how much was the "virtually zero draw" with everything off?

Very odd that Yuasa smart-charger wasn't working to keep battery changed. Their multi-stage algorithms are typically much, much better for long-term storage than trickle-charge tenders. Might be case of bad battery tricking charger. It only has surface-charge on plates, which puts out full voltage and fools charger into thinking it's done. But as soon as you turn key ON, voltage drops tremendously and there's nothing left to start bike and run ECU.

 

[dwalby]

Back to your original post, if a brand new battery is fully charged, and there is no parasitic draw, your battery shouldn't degrade to the point you described after only 2 weeks. So I wouldn't consider your problem solved just yet. And as Andrew mentioned, you should be reading 1 or 2mA parasitic drain, if you were really seeing 0 then there's something wrong with your measurement technique.

12.2v isn't a fully charged battery.

I don't know what the probability is that you got a bad replacement battery, but that's a possibility based on what you've told us so far. However, if for whatever reason your new battery has never been fully charged, that's another possibility. As Dave mentioned, put it on a known good charger that is capable of charging it fully overnight, and try again. Based on the 12.2v reading whatever you charged it with this last time is a little better than before, but not really giving it a full charge. Or, there's something about the new battery that is causing it to not take a full charge to 12.6v.

When you went on the 8 hour ride with 3 or 4 stops, what was the total riding time? If it was only a couple hours total, that may have not been long enough to fully charge the battery. If it was more like 6 or 7 hours, then that may mean the battery isn't quite up to what it should be performance wise, and you should consider returning it to wherever you bought it and have it tested.

First step is to re-run the parasitic drain test and report back with the current figures. Saying it was virtually zero doesn't sound right unless you consider 2mA virtually zero.

 

[desmo900]

Well, after all the thoughtful brain work by myself and various folks here on the list, my issue ultimately turned out to be a rare bad new battery purchased. I had it tested by two independent sources, and the battery failed load and health tests both times. We’re up and running reliably with a new battery. Thanks again to all for your time and comments. Stay safe out there!