battery charger questions

[Paul In Australia]

You are all going to hate me for this but I am confused after reading several different blogs.

I own a 2008 R1200rtSE. I have bought a motorcycle battery charger and want to connect up directly to the battery. Leave the connections ( which come with a waterproof setup for this purpose under the seat.

DO I or DO I NOT have to disconnect the negative terminal from the battery each time before charging the battery ? pain if I do, and If I do I will take the charger back and buy the expensive BMW can bus friendly charger, but would prefer not too.

regards

[Bullett]

We've always removed the battery (or disconnect it) to use a "regular" non canbus charger. The dealer "gave" me a canbus charger when I bought the F650GS, that we are now rotating through all 3 of our canbus bikes.

 

Hey, wait a minute, isn't it summer where you are? Go ride to keep your battery charged!

[T__]

Paul, according to BMW you should.. An awful lot of us don’t disconnect & have had no problems.. I guess it comes down to trusting your battery charger..

 

BMW seems to think disconnecting the battery during charging the battery will prevent the bike’s electrical system’s electronics from seeing over 15 volts if a battery charger is used that exceeds that voltage..

 

Personally I don’t worry about that as my charger is pretty well clamped & regulated.. But I sure wouldn’t use an old analog 60 amp truck battery charger either..

 

Twisty

 

 

[T__]

Was doing some Service Bulletin research for another member here & ran across this bulletin in my archive data folder..

 

I don’t personally use a special GEL battery charger so it won’t change my way of charging my BMW batteries but thought I would post it here so people could make up their own mind..

 

 

 

Twisty

[bobbobtar]

I use a Deltran Battery Tender Jr.on my 2007 R1200RT have had the bike on it for months,also used the same charger on a K1200LT for two years,not a bit of problems on either bike.I attached the pigtail to the battery and when not ridding for awhile I'll just plug it in.

[Koop]

I use a Deltran Battery Tender Jr.on my 2007 R1200RT have had the bike on it for months,also used the same charger on a K1200LT for two years,not a bit of problems on either bike.I attached the pigtail to the battery and when not ridding for awhile I'll just plug it in.

 

Battery Tender Jr is not recommended for gel batteries as it can charge at too high voltage. The correct Deltran charger is the Battery Tender Plus P/N 021-1056, this is has specific software for gel batteries (do a search - much discussion on this).

 

Using the Jr for "months" may not be good example. Let us know down the road how the battery performs. My previous experiences with Deltran Battery Tender's have been outstanding - getting up to five years of service out of a battery that's usually good for three years at best.

[T__]

Koop, actually the Deltran battery tender Jr. is probably the best choice for the BMW GEL battery in the BMW 1200RT if you don’t want to disconnect the battery during charging..

 

According to the Deltran info the battery tender Jr can be used on GEL cell batteries.. It just isn’t the best recommended as I don’t believe it has the high voltage cycle (that would probably come under the BMW disconnect recommendation).. They have a (note*) for the selection of Deltran battery chargers (see below)

 

 

 

 

“*Note*: All Deltran battery chargers will charge all types of lead acid batteries: either flooded (standard STD), sealed maintenance free Absorbed Glass Mat (AGM), or sealed maintenance free gelled electrolyte (GEL) batteries. However, for optimum battery performance in deep cycle applications (for example, running a trolling motor), it is best to chose the Deltran charger that has the charging software specifically designed for the battery type. Fortunately, since the technical staff at Deltran has developed charging software that works equally well for both STD & AGM batteries, the only choice to be made is between 2 models: either STD & AGM or GEL software.”

 

 

Tender Jr. info as follows—

 

 

 

The Battery Tender Junior is much more than a trickle charger. It has a brain. It's lightweight, compact, and fully automatic; very easy to use, especially in small spaces. It will keep your battery fully charged so that it is ready to go when you are!

Perfect for all lead-acid, flooded or sealed maintenance free batteries (AGM and gel cell).

Complete 4-step charging program (Initialization, Bulk Charge, Absorption Mode, Float Mode).

Automatically switches to float / maintenance voltage after fully charging the battery.

If the battery voltage drops too far under load, full charger output power resumes.

Solid state two color LED indicates stage of charger.

Spark proof.

Reverse polarity protected.

12' output cord.

5 year warranty

 

Twisty

 

 

[Koop]

The information on the web site is a bit misleading. When I spoke directly to Deltran I was told their chargers can charge at voltages as high as 14.9v (depending on state of charge of the battery).

 

The 021-1056 is optimized for gel and never exceeds 14.2v. Gel batteries generally won't tolerate charging above ~14.5v for extended periods.

 

So, technically yes, you can charge a gel battery with any battery tender. But if the conditions allow the charger to charge at voltages above 14.5v for extended periods it will damage the battery.

[JayW]

Thanks for posting the BMW TSB, Twisty. Since I never use any kind of battery charger (other than the alternator), I guess my battery has never been through the "desulfation cycle" that is built into the charging algorithm. Even though I ride at least weekly all year long, I wonder if using the recommended charger periodically might prolong the life of a GEL battery.

 

Jay

[T__]

Thanks for posting the BMW TSB, Twisty. Since I never use any kind of battery charger (other than the alternator), I guess my battery has never been through the "desulfation cycle" that is built into the charging algorithm. Even though I ride at least weekly all year long, I wonder if using the recommended charger periodically might prolong the life of a GEL battery.

 

Jay

 

Jay, I’m not sure the “desulfation cycle" is a big deal on any battery that isn’t run down then constantly brought back up (like a deep cycle battery or boat batteries) or on a battery that isn’t allowed to sit dormant in a partially charged state..

 

The “desulfation cycle" seems to be a bigger deal on batteries that are used in safety lighting or stationary applications..

 

 

Your motorcycle battery gets a pretty good pull down during cranking then a pretty good hit from the alternator after each start up..

 

Even Deltran (the battery charger maker) doesn’t think it is a big deal on the non deep cycle applications as they approve the use of standard Tender Jr on the GEL batteries & it doesn’t have a GEL “desulfation cycle" on it..

 

I never charge my motorcycle batteries during riding season as I ride them often enough to keep the batteries up but do hit them with a charger a couple of times each during the off season.. I usually get about 5 years out of the AGM batteries I have been using.. Not sure on the GEL battery in my new BMW (I guess time will tell).. I’m planning a trip to Alaska next summer so will probably install a good AGM before the trip to preclude any battery issues (even though my current GEL will be less than a year old).. I just don’t like the GEL battery for motorcycle applications as they are just too fickle & temperamental..

 

I have an AGM battery in my old GoldWing that has been in that bike for almost 6 years & the charging system on that bike runs right at 15.1 volts on a hot engine at freeway speeds.. That is too high according the battery supplier but I don’t think the battery can read the fine print..

 

Twisty

 

[T__]

Koop, there is no 021-1056 GEL battery charger..

 

Twisty

[Koop]

You make good sense Twisty, I'm probably being an anal factory type here.

 

It really depends on the internal resistance of the gel cell. If you don't deep cycle it, it probably won't see excessive voltage from a Deltran Battery Tender (whether it's a Jr or Plus or Whatever).

[Koop]

Koop, there is no 021-1056 GEL battery charger..

 

Twisty

 

There certainly is; I bought one. You have to call them. It doesn't show up on their website.

[bobbobtar]

koop,I've not had a problem with the last four bikes on a Battery Tender Jr.but then I haven't keep a bike for more than 3 years,they all were plug in for at least 4 months.

[Koop]

Take a look here: It's the 021-1056:

 

http://www.batterymart.com/p-battery-tender-plus-12v-1_25a-gel-battery-charger.html

 

For info, you'll need to contact Deltran

[T__]

Take a look here: It's the 021-1056:

 

http://www.batterymart.com/p-battery-tender-plus-12v-1_25a-gel-battery-charger.html

 

For info, you'll need to contact Deltran

 

Nope, that is a DEL-021-0156 not a 021-1056..

 

Twisty

 

 

[Deek]

I think there is confusion talking about BMW Gel batteries and Battery Tender chargers.

 

I keep reading "Battery Tender PLUS" and "Battery Tender JUNIOR" models, used interchangeably; and I'm assuming there must be a difference in those two units as to their charging characteristics. I never thought the BT JUNIOR was a charger.....always thought it was what I call a "maintainer".

 

I have been using a BT JUNIOR (standard model) on my 1200RT once a week when the volts drop down to 12.4 and I think I might go riding in a few days. I started doing this about 1 month ago. I've had problems with the battery that I think stem from a short somewhere that predates my using the BT Junior. I have no idea if I am damaging the battery, but I cannot imagine using it for only 2 hours or so once a week when the volts are around 12.4 can do any damage.

 

But I could be wrong.

 

PS - I have NOT been able to find a "Gel model" Battery Tender JUNIOR (not a PLUS). I don't think one is available. If I'm wrong someone please tell me!

[T__]

Deek, actually you can damage the battery by undercharging it… If the 2 hours doesn’t bring it up to full charge or allow the charger to get to the float cycle then you could be shortening the battery life by allowing sulfation..

 

You say

I keep reading "Battery Tender PLUS" and "Battery Tender JUNIOR" models, used interchangeably

 

I sure don’t see or read that anywhere in the thread above.. In fact just the opposite.. Please point out where we use the two interchangeably?

 

As far as one being a charger & the other a maintainer? I sure don’t know where you got that from.. They are both chargers & both maintainers.. One just has a more power to charge quicker & the Tender Plus has an additional algorithm in it to recognize GEL battery’s then modify the charging slightly to better charge a depleted GEL battery..

 

Twisty

 

[Deek]

Deek, actually you can damage the battery by undercharging it… If the 2 hours doesn’t bring it up to full charge or allow the charger to get to the float cycle then you could be shortening the battery life by allowing sulfation..

The BT Jr light goes from red to flashing green to green in about 2 hours. I'm assuming the battery is fully charged at that point, but I don't know what volts that should be if it's fully charged. I read 12.8 or close to that once the light goes to steady green.

 

You say "I keep reading "....Battery Tender PLUS" and "Battery Tender JUNIOR" models, used interchangeably...."

 

I sure don’t see or read that anywhere in the thread above.. In fact just the opposite.. Please point out where we use the two interchangeably?

 

Jeez, now don't get all defensive on me, this forum is not the only one that discusses battery chargers, etc.

 

As far as one being a charger & the other a maintainer? I sure don’t know where you got that from.. They are both chargers & both maintainers.. One just has a more power to charge quicker & the Tender Plus has an additional algorithm in it to recognize GEL battery’s then modify the charging slightly to better charge a depleted GEL battery..

 

Twisty

 

I suppose it's my choice of words. The BT Jr I believe only pushes 0.75 amps, which sounds more like a maintainer to me (my term, I don't know if that has any technological standing. ). My other (non BT) chargers use 2.0 amps as the lowest setting.

 

So you are the opinion using my BT Junior for just topping off (so to speak) my Gel battery might harm the battery? If that seems to be the consensus I will have to try to find a BT Plus for Gel batteries since I don't think DelTran makes a BT Junior for the Gel....at least I have not been able to find one.

 

Also, you mention the BT Plus (if a Gel model?) has that additional feature to better charge a "depleted GEL battery". Do you mean really low, like down to 10 volts or so? Or just 12.0 or so on a bike that's been sitting for a month or more maybe? My bike won't got more than 2-3 weeks without being ridden, and I don't think my battery would ever get "depleted". Heck, maybe I'm, better off NOT connecting it to any kind of BT or other charger/maintainer!

 

BTW Twisty, I went back through this thread as I try to get educated.....I found where you said "....Koop, actually the Deltran battery tender Jr. is probably the best choice for the BMW GEL battery in the BMW 1200RT if you don’t want to disconnect the battery during charging..". Now since I also don't disconnect the battery in my 1200RT why is it not my best choice also? I am so confused. You said the BT JR was "the best choice" for his battery, but I by using a BT Jr I might be damaging my 1200RT battery?

 

In that same post above you quoted from Deltran above "....The Battery Tender Junior is much more than a trickle charger. It has a brain. It's lightweight, compact, and fully automatic; very easy to use, especially in small spaces. It will keep your battery fully charged so that it is ready to go when you are!

Perfect for all lead-acid, flooded or sealed maintenance free batteries (AGM and gel cell). ..." To me that means the BT Jr is designed to keep my Gel battery fully charged.

 

Maybe I'm going nuts but I am confused again!

[T__]

Deek, .75 amps will charge your battery just fine it just takes longer than a 2 amp charger.. The charger amps are not the main factor in charging your battery it is basically the volts with the current controlled or at times constant current that allows proper charging.. 50 amps at 10 volts will not charge or maintain your battery,, on the other hand .25 amps at 15.9 volts will over charge it..

 

You should be able to use your battery tender Jr. to charge your battery.. The Deltran company says it is ok to use the tender Jr. on a GEL battery,, I use the tender Jr. on my BMW GEL battery occasionally during winter storage,, lots of people use the tender Jr for their BMW GEL battery.. It probably isn’t the best choice but is much better than a generic trickle charger or non electronically regulated car battery charger..

 

Just don’t pull the tender Jr. or any staged charger off before it is done if possible.. Once the tender Jr. reaches float stage it is down in the 13.2-13.4 volt range so that is well below any damage range to a GEL battery.. I’m not sure that the charger is completely done when the green light comes on (would have to call Deltran & ask)..

 

Also, you mention the BT Plus (if a Gel model?) has that additional feature to better charge a "depleted GEL battery". Do you mean really low, like down to 10 volts or so? Or just 12.0 or so on a bike that's been sitting for a month or more maybe? My bike won't got more than 2-3 weeks without being ridden, and I don't think my battery would ever get "depleted". Heck, maybe I'm, better off NOT connecting it to any kind of BT or other charger/maintainer!

 

Yes, really low then further operated in the low state of charge (like boat batteries or other uses that continually deplete batteries with no constant charging to keep them up)

 

If you are really worried about your battery by all means buy a special GEL charger with a special set of algorithms that read the battery & properly run the battery through all the GEL cycles.. OR,, my take is to use the tender Jr. as many have been doing for a long time now.. When the BMW GEL battery finally dies use the money that you would have spent on a new GEL battery charger to buy a good quality AGM (glass matt) battery then you can use your tender Jr. again & have a better more robust battery in your bike to boot.. Personally I have never liked GEL batteries for motorcycle use,, too many cons & not enough pros..

 

 

BTW Twisty, I went back through this thread as I try to get educated.....I found where you said "....Koop, actually the Deltran battery tender Jr. is probably the best choice for the BMW GEL battery in the BMW 1200RT if you don’t want to disconnect the battery during charging..". Now since I also don't disconnect the battery in my 1200RT why is it not my best choice also? I am so confused. You said the BT JR was "the best choice" for his battery, but I by using a BT Jr I might be damaging my 1200RT battery?

 

BMW recommends that the battery be disconnected or isolated before charging with any charger other than the BMW high dollar special charger.. Best I could determine that was to protect the on board motorcycle electronics from any voltage above 15 volts.. The tender Jr. doesn’t have a GEL cycle so shouldn’t get over 14.4 for most charging & maybe a quick pulsing to 14.9 volts.. A true GEL charger can have a pulsed or quick mid 15 volt cycle for equalization.. Not sure all do but is possible..

 

 

Twisty

 

[Deek]

Any idea what a good Glass Mat battery for my bike costs.....just in case the one I have now is trying to die?

 

I still plan to take this battery into the shop to have it load tested. I've heard that ought to give me ultimate word on it. The problem I had initially was I had an XM radio on it that used a 12 to 5 vlt converter that continually charged the radio's internal battery. I was told that was enough of a draw to have the battery be too low to start the bike (we're talking under 7 volts!) after several weeks of sitting in the garage. That radio circuit is no longer in the system, and I THINK I've eliminated any draws on the battery that were not there when the bike rolled off the assembly line.

 

But I will not be surprised to hear my battery is ill.........

[DoctorC]

I have used the Jr model for two years..wired directly to the battery... plug it in every time the bike is in the garage...glows green after a few seconds...and never had a problem. Never used it to charge a dead battery, though.

[bobbobtar]

Deek,

I was a little confused by your statement "The BT Jr light goes from red to flashing green to green in about 2 hours I'm assuming the battery is fully charged at that point"so I ran down to the garage to look at the Jr which has been plugged in for about 6 weeks the green light is flashing, I think this means its in float mode.

[DoctorC]

Two seconds, not hours... I believe once charged, it floats! But then again, I lost the instruction manual ages ago... and I like the color green... figure green is good, right?

[Deek]

Bobbobtar and DoctorC:

I said earlier ""The BT Jr light goes from red to flashing green to green in about 2 hours I'm assuming the battery is fully charged at that point""

 

I'm guessing about the 2 hour part, as that's the time it took me to grab a shower, change clothes, but away the motorcycle stuff and check on the BT Jr in the garage. I don't know how long the green light was flashing, but I only saw it once.

 

Text on the BT Jr says a flashing green means "80% of more charged".