Odyssey PC545 Battery conditioning

[Chuck]

It reads 12.98 this morning. Blasting it with 10 amps for a couple of hours must have gotten it's attention..

[Chuck]

Still 12.96.. King, I'm calling this case closed. 

[docc]

Still 12.96.. King, I'm calling this case closed. 

That's it! Nicely done.   Another AGM recovered.

 

So, would you say it was the discharge followed by applying amperage in excess of 6 amps (10 amps in your case)?

[Chuck]

 

Still 12.96.. King, I'm calling this case closed. 

That's it! Nicely done.   Another AGM recovered.

 

So, would you say it was the discharge followed by applying amperage in excess of 6 amps (10 amps in your case)?

 

Must have been. It went down last fall and I just put it on a tender overnight. I thought, "WTF?" I've left Odyssey batteries for months on end out in SoCal without issue. Go out, punch the button and go.  I can probably do the same with this one, now.

[Guzzi2Go]

Docc,

          The VII charging system looks at the battery Voltage, if it's a bit low it connects the alternator to the battery and pumps in whatever the alternator will produce, once it starts it can't stop or limit the current until the end of the current cycle, think of it as as a large charger with a switch rapidly turning on and off.

This all happens 14 times for each engine revolution.

I suspect the current pulses are well over 30 Amps, this would explain why the 30 Amp fuses melt

 Heat is current squared x resistance.

(I did measure the current once but have forgotten)

 

To back off the regulator skips half cycles,

 

The V11 regulator is a series type, it controls the average current.

The shunt regulator most other bikes have can control the peak current by shorting out the alternator when the Voltage gets too high thus removing the power source to the rectifier.

 

BTW as you know the alternator can put out a very high Voltage, well over 60, this is why you must never try to run without a battery to soak up the spikes.

 

When I first got my V11 Sport the regulator quit, I was able to limp home using just a bridge rectifier (no regulator) but I had to keep the revs low or the ECU would shut down.

Sorry to say so, but this does not sound right to me...  (if these statements have been retracted in the meantime, I apologize for pointing to them "again")

 

The "charging system" on the V11 consists of nothing more than a voltage regulator (not a current regulator, as stated above). In Guzzi's case, it regulates to 14-14.6V on its own terminals (not battery). The voltage on terminals never exceeds 14.6V, If it does, the regulator is faulty.

 

Charging current is theoretically limited by the regulator's voltage, battery's state of charge (voltage on the battery with no load), battery's internal resistance (milliohms range) and parasitic resistance of the wires and connectors between the charger and the battery (also low ohm range), practically however it is limited by the alternator's/regulator's capacity.

 

Max current that the regulator can deliver is 27,5A@10k RPM (~400W). You will need roughly half of that to supply the regular load (150-200W), so not more than 10-15A will be available to the battery at any time. 

 

Only battery can blow the 30A fuse, regulator cannot. If it's blown, there is a short southward of the battery/fuse.

 

Docc, where did you find that info on "battery priming"? Odyssey is quite explicit on "never exceed 15V" and their charger's documentation also does not provide any statements on high current/voltage spikes. Can you perhaps post a link to a document?

 

I know my comment is more than a year late and I sincerely hope it does not spur a flame war. This is definitely not the intention.

[Chuck]

As this thread popped up again.. the 545 checks 12.94 today.   Apparently, once that 10 amp charge got it's attention, the alternator has no problem keeping it topped up. 

[docc]

Docc, where did you find that info on "battery priming"? Odyssey is quite explicit on "never exceed 15V" and their charger's documentation also does not provide any statements on high current/voltage spikes. Can you perhaps post a link to a document?

 

I know my comment is more than a year late and I sincerely hope it does not spur a flame war. This is definitely not the intention.

 

Guzzi2Go, thank you for your excellent post!   I have edited and amended my posts throughout the thread. As you say, no more than 15vDC charging! (Amperage is "unlimited", but should not be below 6 amps  to *charge* the PC545).

 

Regarding the "battery priming" (discharging before starting or charging?):

 

 

>Here is the reference post: http://www.v11lemans.com/forums/index.php?showtopic=18838&p=201259

 

>The post with the "empirical" observation:

http://www.v11lemans.com/forums/index.php?showtopic=18838&p=208912

 

> This is the *technical bulletin* that I have referenced for some of my conclusions:

 

http://www.cdtechno.com/pdf/ref/41_2128_0212.pdf

 

> EnerSys (Odyssey) technical reference: “reconditioning charge cycle procedure.”

 

    Note "Action Procedure: 1. Discharge the battery . . ."

 

http://www.odysseybattery.com/documents/ODYSSEY_Battery_Reconditioning_Charge_Procedure.pdf

[Guzzi2Go]

Thanks docc, this is a very nice and informative document

http://www.cdtechno.com/pdf/ref/41_2128_0212.pdf

 

Must admit, did not read all of it, but still, I think there is some misunderstanding related to these two present:

1. EnerSys (Odyssey) technical reference: “reconditioning charge cycle procedure.”
2. (Amperage is "unlimited", but should not be below 6 amps  to *charge* the PC545).

 

#1 is about lead sulphate buildup removal. Not sure if this is really needed with new batteries. "Pure lead" batteries have allegedly very long shelf-life. I assume this means they are resistant to sulphate build-up, at least when new. I may be wrong here, though. 

 

"Lead-acid batteries can develop reduced delivered capacity / performance after prolonged periods of storage, especially if the  batteries were not periodically boost charged or left on a float / maintenance charger during the time of storage. The cause of this reduced capacity is the development of sulfation of some of the oxide on the plates. "

 

Two ways of achieving this:

1. Have charger drive high current through the battery. This is what Odyssey is talking about in their paper and requires high power charger, practically empty battery and some degree of care - "If the battery gets hot to the touch (exceeds 125⁰F), stop charging and allow to cool". The battery needs to have as low voltage as possible, so the charger would not need to contend with battery's voltage in addition to its own and battery's internal resistance (Figure 3, page #7 of the tech bulletin - assume R_r=0).
2. Have battery drive high current through the charger. Here the charger shorts the battery for a very short period (typically 100µs), generating a current spike of ~100A. Odyssey also talks of this in their chargers data sheet - http://www.odysseybattery.com/documents/ody_chargers_sheet.pdf "Storage recondition mode"

The latter is safer if battery is left connected while being charged/maintaned. The 1st method may cause overvoltage and burn ECU or so.

 

 

#2 Amperage is not unlimited. The amperage is limited by the charger's capacity and that is, in Odyssey's case, 6, 10 or 20A

 

So it is not "not below 6A", it is "not more" than 6A (or 10 or 20). The strategy used by the charger seems to be "Modified constant voltage-limited current" (tech bulletin page 14 and Odyssey's data sheet ), where the charger starts with max. rated current and reduces it as the battery voltage rises.

 

The document also states: "Occasionally, constant current at the C/3 to C/5 rate is proposed as a fast charging technique", C being the capacity in Ah. This gives a hint why Odyssey deems 6A charger sufficient for PC545 (13Ah -> 6A = ~C/2, charging is still "fast"). So this is more about "being quick" than about "doing the right thing for the battery".

 

Comments/responses are welcome.

 

 

 

 

[docc]

All good thinking and well said.

 

The EnerSys technical document I linked is, obviously, for deeply discharged batteries. As such, the discharge voltage of 10 volts (hopefully) does not apply to our situations. The 12.65 volt threshold is in the PC545 owner's manual with the emphasis that the battery should be "kept near full charge, approximately 12.8 volts."

 

I am looking further for the references to "unlimited" amperage. The most often repeated concept is that the minimum amperage must be applied in order to effect a charge (6 amps "minimum" for the PC545), and that low amperage "trickle" or float devices will not charge the AGM battery and will be damaging if below 13.2 volts.

[Guzzi2Go]

I think more or less everything one needs to know is in the tech bulletin document you linked to in your earlier post.

 

Refer to chapter "Thermal runaway and VRLA battery charging" on page #24. There it says that too high current for too long. may damage (cook) the battery.

 

On page #20 it is stated that the temperature during charging should not rise for more that 10°C, and that deeply discharged batteries should not be charged with more than C/5 Amps.

 

The "unlimited" is mentioned on page #12, "Constant voltage, unlimited current charging", but there it is also stated that: "very high initial current accepted by the battery will cause excessive heating and can be detrimental to the active materials in the plates".

 

What I did not find in the document is that there is a minimum current required to charge this or that. 

[docc]

 

 

The current (eighth) edition of the Odyssey manual only has the "minimum charge current " language specific to each battery model(page 14, Table 3:

http://www.odysseybattery.com/documents/US-ODY-TM-002_1214.pdf

 

I realize that the discharge method is not in the manual unless the battery is deeply discharged, yet I have found the technique effective. Especially when a battery develops the 15v maximum voltage very quickly, the discharge helps (apparently?) get *deeper* into the plates.

[docc]

I see the Odyssey charger bulletin has been superseded (link repaired). I believe the "comments" on the 2011 document are pertinent to the charge current discussion:

[docc]

 . . .  "doing the right thing for the battery".

 

Comments/responses are welcome.

This is what I remain most interested in . . .

 

Thank you, Guzzi2Go for the excellent input and assistance in making this thread the best it can be for all V11 owners with these AGM (VRLA) batteries!

[Guzzi2Go]

This is what Odyssey's manual says on the subject: 

 

"As previously indicated, deep cycling applications require a minimum 0.4C_¹⁰ current available from the charger so the values shown in Table 5 do not apply to all products in all applications."

 

The C₁₀ is defined as a 1/10th of the capacity, so in our case: 13Ah/10 *0.4 gives = 520mA minimum charging current.

 

Where it may seem that they contradict themselves is in Table 3, where they state "Battery size and minimum three-step charger current". But that needs to be put in relation to: 

 

"...EnerSys® has developed a special charge algorithm. It is designed to rapidly and safely charge these batteries"

 

So the emphasys here is on speed (and safety, nothing will cook or burn), not so much on attaining full state of charge. To that they add:

 

"The charge times recommended in Table 5 assume that the ODYSSEY® battery is fully discharged and these charge times will only achieve about a 80% state of charge. For partially discharged batteries, the charge times should be appropriately reduced. The graph in Figure 2, showing OCV and SOC, must be used to determine the battery’s SOC. The battery should be trickle charged after high rate charging, regardless of its initial SOC"

 

The "appropriately reduced" is related to manual chargers, not implementing any logic/charging algorithm.

 

So if we are to trust all this, I do not really see anything wrong with applying an intelligent low power motorcycle charger giving ~1A max current. The only thing is that the charging will take longer.

 

Next thing to ask oneself is how much value to put on 100% SoC, achieved by occasional charger use. Do we really need that? Especially if a bike starts readily. After all, the bike will give the battery all the amps it needs.

[docc]

None of my low amp chargers have adequate float voltage (13.5-13.8). They are all below the 13.2v threshold stated to be damaging to the plates.

 

So much of Odyssey's presentation is about deep discharge applications rather than our SIL use (Start-Ignition-Lights). Yet, those charging protocols would be most applicable when we have let our battery get quite low from sitting too long ?