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I have a 2003 K 1200 RS that is need of a new battery. I also have a BMW battery charger that plugs into the accessory outlet.
The question is; what type of battery do I have-lead or gel, what should I replace with-lead or gel, will my old charger work with a gel battery, and is there an online source for purchasing a new battery?
Thanks in advance for your advice.
 

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Many BMW bike owners, including me, are going to the maintenance free Odyssey. If your charger goes to trickle (voltage regulated) mode, then it will be fine. Marketers have successfully convinced many that they need a specific charger for each battery. The important thing is never leave a battery charger connected more than a few hours/overnight if it doesn't have a Trickle mode.

Here's where I bought mine:

http://cgi.ebay.com/ebaymotors/ODYS...616706880QQcategoryZ35594QQrdZ1QQcmdZViewItem

Note the different terminals. I made my own adapter out of copper. You may want to buy one. Odyssey world may have it or I think sierra BMW sells them. Or these guys have it.

http://www.odysseybatteries.com/battery/pc680.htm

--Jerry
 

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Stephejl said:
Many BMW bike owners, including me, are going to the maintenance free Odyssey. If your charger goes to trickle (voltage regulated) mode, then it will be fine. Marketers have successfully convinced many that they need a specific charger for each battery. The important thing is never leave a battery charger connected more than a few hours/overnight if it doesn't have a Trickle mode.
You DO need a specific "trickle voltage" for each type of battery, IF you plan to leave the battery on "float" for a long time. Gel cells, for example, require a slightly different float voltage than flooded cell batteries, and AGMs are also a bit different too. But, again, this is only for extended durations on float.

Similarly, the limited time absorption charge phase voltage (on a proper 3-stage charger) is significantly different depending on the battery type.

Your advice not to leave a battery on "trickle" for an extended time is right on, if your battery charger is a standard consumer type. A "professional" type of 3-stage charger that includes temperature compensated, and accurately controlled voltage control can be left to "float" the battery indefinitely with no damage whatsoever. Many high quality marine battery chargers work this way. But the typical "consumer" battery charger has poorly controlled (or completely uncontrolled) "trickle charge" voltage, and as you say must not be left connected to the battery after the battery has reached full charge.

Bob.
 

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RFWILSON said:
You DO need a specific "trickle voltage" for each type of battery, IF you plan to leave the battery on "float" for a long time. Gel cells, for example, require a slightly different float voltage than flooded cell batteries, and AGMs are also a bit different too. But, again, this is only for extended durations on float.
Bob,
I think you and I have disagreed on this before. I did most of my research a few years ago to make my telescope batteries last longer (70 amp hr gel cell). I work at a multibilliondollar industrial facility with lots of important backup batteries that need to last many many years. I've had extended discussions with our battery engineer (know affectionately as "Batteryman") about proper trickle voltage and he is unwilling to get so specific as the charger manufacturers do saying that the batteries are more tolerant than that. He recommends 2.25 to 2.3 volts per cell but says the range can be larger with no damage. Given the severe service of a motorcycle battery with large, unpredictable loads and a charging system that has to fast recharge because BMW engineers have to assume short trips, I find the overdesigned home chargers silly. Note that you don't change your voltage regulator when you buy a different type of battery....the battery store doesn't ask you what voltage your voltage regulator controls to before seling your a battery. I think it is all marketing fluff.

All that said, I'm always willing to learn. Do you have any links to battery manufacturers websites recommending a specific trickle voltage? And no, I won't be swayed by the charger manufacturers claims that their charger is better for your battery (BTW, that'll be $100 sir) and BMW fits in that category in my book, just trying to sell you another charger.

Here is the trickle charger I use on my car (BMW M-3) and my telescope battery.
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=42292

BTW, I use "float" and "trickle" interchangeably. I think this is correct. Agree? Just want to make sure we're not having a communication issue.

Cheers,
Jerry
 

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Jerry,

First let me preface my remarks by saying that a few years ago I was a senior member of the design team in a major supplier of battery chargers and inverter-chargers to the North American marine, mobile home, and independent power market. (20 amp automatic chargers, up to 3 KW inverter chargers).

I do agree that people can get really carried away about battery charging. I think you are saying that for a quick charge, where you will be disconnecting the charger once the battery is charged, nearly anything will work well. I agree with that. After all, as you indicate, a vehicle charging system is pretty crude itself! I really have to wonder why anyone would pay so much more to get a "BMW" charger, assuming that any other type would somehow damage their "special" BMW battery. Rubbish!

My comments on specific charger requirements for specific battery types, relate only to batteries that are left on float for a long time, and also to 3-stage chargers that use an absorption phase to equalize the cells then bring them to 100% charge. For just bringing a battery that has sat for a while, up to a decent state of charge, nearly ANY charger will work just fine.

Regarding the terms "trickle" versus "float" charging, there is a big difference in the usual terms. Trickle charging is usually assumed to mean a charger that tapers back to a lower current once the battery is charged. But the current is generally not well controlled, and most importantly, the battery's charging voltage is not controlled at all.

Float charging is a tightly controlled regime. The battery current is not controlled at all. Instead, the charger output switches from current limited charge (the so-called "bulk charge" regime) to tightly controlled voltage limiting (or "float") mode. This is needed if the charger is coneected for a long time to the battery (marine and telco batteries being a specific example of this). To maintain 100% charge, the float voltage must be tightly controlled and temperature compensated. A float voltage that is just slightly too high will result in gassing, electrolyte loss, plate erosion and (in the case of gel cels) gas trapped in the gel which reduces the abttery's capacity.

But for the purposes you are referring to, there is nothing wrong with just connecting nearly any charger, and once the battery voltage rises to 14 Volts or so, just disconnect the thing.

Bob.
 

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Bob,
I guess what I'm talking about if float charging, which I have habitually called trickle charging. I'll use the right term from now on.

I think we agree completely on the charge up procedure. But I like to assume that the battery is parked with a pretty much complete charge and only needs a float charger.

What float charge voltages would you recommend for the different types of batteries at about 55 to 65 deg F?

I think I'll have to start calling you Batteryman II, or should I say Batteryman also? Thanks,
Jerry
 

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Stephejl said:
I think we agree completely on the charge up procedure. But I like to assume that the battery is parked with a pretty much complete charge and only needs a float charger.

What float charge voltages would you recommend for the different types of batteries at about 55 to 65 deg F?
First of all, you are quite right: When you stop the motor after a ride that lasts more than a mile or so, the battery is basically fully charged.

I really question the need for float charging an automotive/motorcycle battery in most situations. A lead acid battery will sit perfectly happily for up to 2 months without losing significant charge. Internal leakage, coupled with a few mA drain from the bike's clock or other electronics, is very small. Certainly, if the bike is sitting for only a week or two, there is no point in even bothering with a charger.

As for the correct float voltages, it is now over 5 years since I was involved with this sort of thing on the engineering level, so I would have to do some digging. But remember, this means that you need a charger that can accurately HOLD this float voltage, and most cannot (or have no easy way of adjusting their output).

I suggest that the best approach for maintaining an unused bike battery is to simply put it on slow charge (say, at the C/5 to C/10 rate) every month or so until the terminal voltage reaches 14.0 to 14.2 Volts. Then disconnect it and store the battery (or the bike) in a cool place.

Bob.
 

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I also second the ODESSEY battery. This battery is a drycell, it deep cycles and has great cranking power. It is a great battery.
 

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Agm

The technology to look for is AGM or absorbed glass mat. There are several manufacturers making these types of batteries. An AGM will outlast and and outperform a conventional flooded lead acid battery or a gel battery. Essentially, there are fiberglass mats inserted between the plates and the acid is introduced to the mat. They are sealed and can be shipped as non-hazardous materials. Without boring you with endless hours of engineering babble, these batteries are the stuff. Typically, they have excellent storage properties ( they last well on the shelf or parked in your garage ) and are very vibration resistant. The original battery in my 01 Triumph Daytona is an AGM and it has been most impressive. I bought the bike new in July of 2000 and the battery still works as new. As needed, all of the batteries in my fleet are switching over to this technology.
 

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gblessing said:
The technology to look for is AGM or absorbed glass mat.
The Odyssey IS a type of AGM.

The big difference is that to eliminate the calcium or antimony commonly alloyed to the lead plates to impart stiffness to them, the Odyssey winds pure lead plates into a bandage for rigidity.

Because the plates are pure lead, you get several advantages. First, the internal resistance is WAY lower, resulting higher cranking current. Second, since there is no dissimilar metals in the plates, there is no local "battery" effect and gassing is nearly eliminated, as is electrolyte loss. The battery also keeps its charge a lot longer as well, since there is no alloying elements to form local galvanic couples.

Bob.
 

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RFWILSON said:
The Odyssey IS a type of AGM.

The big difference is that to eliminate the calcium or antimony commonly alloyed to the lead plates to impart stiffness to them, the Odyssey winds pure lead plates into a bandage for rigidity.

Because the plates are pure lead, you get several advantages. First, the internal resistance is WAY lower, resulting higher cranking current. Second, since there is no dissimilar metals in the plates, there is no local "battery" effect and gassing is nearly eliminated, as is electrolyte loss. The battery also keeps its charge a lot longer as well, since there is no alloying elements to form local galvanic couples.

Bob.
The advantages you list are common to all AGM batteries. The odyssey design is one of several very good AGM's on the market. The shape of the cell is marketing not engineering.
 

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gblessing said:
The advantages you list are common to all AGM batteries. The odyssey design is one of several very good AGM's on the market. The shape of the cell is marketing not engineering.
It is the tight bandage shape that allows the Odyssey to use the structurally-weak pure lead plates. Normal AGM batteries use a standard plate struture that requires some alloying of their plates for strength.

Like all low maintenance batteries, AGMs use calcium as the alloying element instead of the older antimony. The result is lower gassing and lower internal resistance, but not as good as when pure lead is used.

Bob.
 
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