odyssey battery

[Ryland3210]

Update: I came home for lunch today and low and behold battery is now at 11.8V, this is with all the relays and fuses pulled. I’m stumped. This problem seems to be above my pay grade and I would happily send the bike to a shop to fix if I believed they could fix it. As a mark one mod zero nail masher I am close to the point where I reach for a bigger hammer. If I didn’t love this motorcycle so much id shoot it.

John. H.

 

 

If your voltmeter has a current measuring ability, I suggest the following:

Disconnect all the wires connected to the positive battery terminal, then measure the current drawn by each, one at a time by connecting the ammeter in between the terminal and the wire to find where the current draw is.

 

Your battery's capacity should be in the range of 12-15 amp-hours, so that corresponds to a discharge rate of about 500 milliamps (0.5 amps) to fully discharge it in 24 hours. I just measured the leakage on mine. It's only 1.12 milliamps! What that means is that the self discharge rate on my battery of just over 21 milliamps is the main factor. That just saved me the trouble of hooking up a disconnect switch, but it means I'll have to recharge the battery every week to 10 days.

 

Your bike is three years older than mine, so it's possible that something on your's remains connected with the ignition off by design, that is disconnected on my bike. But anything more than 10-20 milliamps would cause even a good battery to discharge in a week or two.

 

If you had left everything connected, my best guess would be that the ECU or ignition circuit is somehow staying on when the ignition switch is turned off, but that's really a guess. Discharging in 24 hours as you describe with nothing connected indicates something serious is wrong with the battery.

[dlaing]

When I suggested pulling the fuses AND the relays, pulling the relays was unnecessary if the fuses were pulled.

According to the wiring diagram, removing the fuses should cut off just about everything.

The only place for a leak is the Starter, and the wires leading from the battery to the starter, and the wires leading from the battery to the fuse block.

If you don't have an ammeter, and can't follow Ryland's excellent instructions, do a voltage test between the battery positve and all the positive leads that connect to it.

1 Keep the fuses pulled.

2 Disconnect the negative Wires from the battery.

3 Disconnect the positive wires from the battery.

4 Reconnect the negative wires from the battery.

5 Check the voltage between each of those positive wires and the battery positive. (now I am betting on the starter line )

If you have zero volts, you probably have a bad battery.

If you have more than a volt, you have a leak along that wire, or the starter solenoid at the end of that wire's path, or somebody did something funky with your wiring.

Once determined, either remove the battery by disconnecting the ground or recharge the battery, and reconnect with the following steps.

 

6 Disconnect the negative Wires from the battery.

7 Reconnect the positive wires from the battery.

8 Reconnect the negative Wires from the battery.

[Ryland3210]

One caviat:

 

If the voltmeter used is a high impedance type, even high and acceptable leakage resistance will read a significant voltage. For example, suppose the voltmeter impedance is 1 million ohms, which is not uncommon for battery powered types, often even 5 or 10 times higher. Assume the battery voltage is 12 volts, and the voltmeter reads 6 volts between the positive terminal and a particular lead. That means the leakage current is 6 microamps-which is negligible.

 

Suppose it is an inexpensive, non battery powered voltmeter with a meter movement rated at 10 milliamps full scale. Then the leakage current is still only 10 milliamps if the needle is at full scale, less than that if less than full scale. That's still less than half of the typical battery self discharge rate with nothing connected.

 

If an ammeter is not available, the next best thing is an ohmmeter. A leakage rate of 24 milliamps at 12 volts, which is about the self discharge rate on my "good" battery, corresponds to 12/.024, or 500 ohms.

 

If a resistance of less than 200 ohms is read, I would consider that something to track down. At 40 ohms, your battery will be dead in less than two days.

[dlaing]

One caviat:

 

If the voltmeter used is a high impedance type, even high and acceptable leakage resistance will read a significant voltage.

Thanks, I should know that But I still don't quite grasp the difference between impedance and resistance. Capacitors and Inductors also perplex me.

In my ECU leak problem the 10V reading with 70milliamps perplexed me (I thought 10V was higher than what I expected for that low of a current) but the impedance of the meter explains it.

This also explains why I can't calculate the wattage running in series through both filaments in an H4 lamp.

 

In any case, the voltmeter test may help him check which positive lead might be the culprit, but determining if it is the battery or a leak would require charging the battery, disconnecting and seeing if it drops below 12V/

[Ryland3210]

Thanks, I should know that But I still don't quite grasp the difference between impedance and resistance. Capacitors and Inductors also perplex me.

In my ECU leak problem the 10V reading with 70milliamps perplexed me (I thought 10V was higher than what I expected for that low of a current) but the impedance of the meter explains it.

This also explains why I can't calculate the wattage running in series through both filaments in an H4 lamp.

 

In any case, the voltmeter test may help him check which positive lead might be the culprit, but determining if it is the battery or a leak would require charging the battery, disconnecting and seeing if it drops below 12V/

 

Impedance is the combination of resistance, inductive reactance and capacitive reactance making up a load.

 

Let's say the voltmeter spec says, for example, that the input impedance is 1 megohm across 20 picofarads capacitance. The time constant of the input is R X C, or 20 microseconds. The human eye cannot see anything that fast. That means that for measurements of DC voltages observed by the meter, the 20 pF capacitance is negligible, and it might as well be zero, so the input acts like a pure resistance to the eye.

 

If you were measuring a 60 Hertz AC voltage, the capacitive reactance of the 20 pF capacitor is 136 megohms. (the formula is 1 divided by ( 2 X PI X FREQUENCY X CAPACITANCE)) Since it is in parallel with the 1 megohm resistance, it decreases the load impedance about 0.7%. So at low frequencies, there is very little difference, whether measuring DC or AC. At a frequency of 6,000 Hz, the capacitive reactance drops to 1.36 megohms, so the load is then 0.576 megohms-big difference.

 

Inductive reactance is equal to 2 X PI X FREQUENCY X INDUCTANCE, so it is zero at DC and increases with frequency.

 

Resistance is constant for all frequencies and DC.

 

Bottom line is that for voltmeters, the resistive component of the input impedance is all that matters for DC measurements.

 

Hope I didn't bore you to death on the way to the bottom line!

[dlaing]

 

Hope I didn't bore you to death on the way to the bottom line!

Not bored, but this emoticon expresses it

 

Would an analog voltmeter tend to have lower impedance?

Would the voltage of the batteries in the volt meter give a clue to the impedance?

[dlaing]

Impedance is primarily a term used in alternating current circuits.

 

The meter load is expressed in Ohms per volt. A good moving coil 9analog) meter is around 20,000 ohms/volt, a cheapie may run 1000 to 5000 ohms per volt. Digital meters and vac tube or FET meters are much higher, in the megohms per volt trange.

Thanks!

I have a few older meters that are kind of half working, maybe I'll give them a try(if I did not leave corroding batteries inside of them ), just to see the variations.

[Guest Gary Cheek]

The series shunt resistance is another consideration when reading amperes. Usually the higer current ranges place a lower resistance in series. The series resistance is part of the circuit and will affect the accuracy of any reading. In most cases it is not a cause for concern.

[Ryland3210]

In simple meters, the battery is used only for resistance measurements, so the volt and amp ranges will work with a dead battery.

 

Although it's true the shunt resistance will affect measurements of current, in a 12 volt system, the shunt resistance will be low enough that the voltage drop will be small compared to 12 volts accross the shunt. Therefore the readings will be accurate enough for measuring leakage currents in the 10-20 milliamp range or higher within something like 10% accuracy. That should be fine for your purpose.

[Guest Gary Cheek]

I wasn't really implying the readings would be useless, just a bit different than the actual current (highr) with the meter out of the circuit. I'm sorry if you somehow wanted to read it that way.

 

Actually the shunt resistance is determined by the current range and the meter's sensitivity, not the voltage of the circuit being measured. The lowest resistance shunt is in the high current (10 or 20 Amp) range. While this affects the circuit the least it also provides minimal resolution at the low current readings( fewest digits right of decimal).The lower current ranges rely on a larger series resistance to get a sufficient voltage drop .

 

The most SENSITIVE meters require lowest resistance shunts for a given reading. This means they have the least affect on the circuit being measured. Some cheap meters rely on a fairly large resistance when measuring current.

 

 

I was merely adding the comments as a reminder that the circuit behaves differntly when the meter is removed.

[Ryland3210]

I wasn't really implying the readings would be useless, just a bit different than the actual current (highr) with the meter out of the circuit. I'm sorry if you somehow wanted to read it that way.

 

Actually the shunt resistance is determined by the current range and the meter's sensitivity, not the voltage of the circuit being measured. The lowest resistance shunt is in the high current (10 or 20 Amp) range. While this affects the circuit the least it also provides minimal resolution at the low current readings( fewest digits right of decimal).The lower current ranges rely on a larger series resistance to get a sufficient voltage drop .

 

The most SENSITIVE meters require lowest resistance shunts for a given reading. This means they have the least affect on the circuit being measured. Some cheap meters rely on a fairly large resistance when measuring current.

I was merely adding the comments as a reminder that the circuit behaves differntly when the meter is removed.

 

Clearly understood, Gary. I started using voltmeters and designing instruments working at HP in the 60's. I still occasionally design circuits, mostly in the high performance closed loop controls area. It's clear you and I have a thorough understanding of the theory and practice of voltmeters. My concern was to clear up any uncertainty our friend with the problem might have with "In most cases ... " being non specific. That's why I wanted to let him know that in his case, for the range of voltages and current involved, he didn't have to worry.

[Guest Gary Cheek]

HP made some of the very best lab gear to be had. Their audio generator is a classic. It would have been nice to have worked with you there. I got my start in electronics about the same time but not as a pro of any kind. I got my ham license at 11 years old in 1961 but, as you know the test was a bit harder back then.(Amateur Extra class) Along with the 20 WPM code test. I still use only 1950s vintage ham gear today!.

I did a 2 year stretch at Sun Electric Industrial Systems Division in the 1980s. We designed and built autmated test systems for production plants.We also spent 6 weeks every summer at Laguna Beach doing emissions data gathering, Cal spec. The flip side was we usually spent the winters setting up a line in some place like St Catherines Ontario. 14 hour days, 7 days a week for 5 months was the worst stretch!

Thanks for the input, it is nice having you around!

[Ryland3210]

HP made some of the very best lab gear to be had. Their audio generator is a classic. It would have been nice to have worked with you there. I got my start in electronics about the same time but not as a pro of any kind. I got my ham license at 11 years old in 1961 but, as you know the test was a bit harder back then.(Amateur Extra class) Along with the 20 WPM code test. I still use only 1950s vintage ham gear today!.

I did a 2 year stretch at Sun Electric Industrial Systems Division in the 1980s. We designed and built autmated test systems for production plants.We also spent 6 weeks every summer at Laguna Beach doing emissions data gathering, Cal spec. The flip side was we usually spent the winters setting up a line in some place like St Catherines Ontario. 14 hour days, 7 days a week for 5 months was the worst stretch!

Thanks for the input, it is nice having you around!

 

Thanks for the kind words. You've certainly had an interesting career.

 

Yeah, it was great working for a company that always strove to be the best at what they did. HP's manaagement by objectives was enlightened compared to theory X, prevalent at the time, in which decisions were driven top down, similar to the military. They also let engineers like me get involved in marketing and production, which helped stimulate many to become entrepreneurs, just like Dave and Bill. In spite of losing people as they spun off on their ownt, the company prospered nevertheless. Several of the people in my division started their own successful companies, one of which was the world's first word processor.

 

The audio generator figured strongly in Walt Disney's early cartoon production, though I never found out how. A large government contract around WWII timeframe gave them the chance to grow.

 

I admire Bill Hewlett for being the one director to steadfastly objected to the merger with Compaq, while Carly, the CEO of Compaq and the other directors voted to give themselves huge bonuses just for doing the deal. Bill was absolutely right when he asked why would HP want to increase its participation in the highly competitive, low margin PC business. He was thinking about the shareholders. Carly and the others were thinking about the bonuses. I have owned HP stock since I worked there. It took years after Bill lost the battle before Carly was fired and the company turned around.

 

I am grateful for all HP taught me and the encouragement they gave me to strike off on my own when I was ready. We had tremendous freedom to innovate, and to use the company's facilities for personal projects. I used the degreasing pit to clean my carburettors, and once even my Harley's engine block.

That was nothing compared to the guy who ran the plating shop that plated all the bright work on his Harley in gold, again all with the blessing of management. There was a monthly bonus system that averaged about 30% of base salary. We were the highest productivity division, largely because of enlightened management and the dedication of all of us.

 

I designed and built an electronic distributor and voltage regulator before these were available on the market, all with the blessing of management. Too bad I didn't patent either one. I still have the distributor.

 

I'm impressed you got your Ham license. I got as far as to set up a short wave radio, and got a kick out of listening to broadcasts from Europe, and from Radio Moscow's English language propaganda. It's an indication of our Nation's self confidence that their signal wasn't jammed, while Moscow tried its best to jam Radio Free Europe.