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Whether or not battery tenders are really necessary

bobnmona

Just a happy rider...
Hi,

I've ridden lots of different motorcycles over the last 40 years and other than a 1991 Suzuki GSX1100F that really did need to be hooked to battery life-support every minute that I was not riding it, all my BMWs have done very well without tenders at all.

Granted, I live in northern California, 45 or so miles south of San Francisco, and my weather is great for riding 365 days of the year, I've never suffered from any failure to start for as long as I've had my Beemers, which are ridden at least five days a week.

The current bike I ride as a daily commuter, three miles to work and three mile back with the occasional ride to Half Moon Bay to eat lunch, is a 2004 R1150GSA that has a nearly three year-old PC680 Odyssey drycell motorcycle battery that is still going strong, despite the fact that it has never been placed on a charger. Since I read another post tonight concerning a battery tender that wasn't able to properly charge the battery, it got me wondering why would anyone else in similar conditions (especially during the summer) need to worry about charging their batteries if they rode daily and made sure that the bike was charging properly?

I'd appreciate hearing your experiences and opinions!

Best cheers,

Rob
 
Rob, I live just over the hill from you in Santa Cruz. The modern bikes (R1100 and newer) have excellent charging systems. My hexhead bike never needs a charge, either.

The Airheads that preceded them had excellent charging systems *for their time*, but would not like what you do to your oilhead, because the charging system on those bikes discharges at idle and doesn't really get going until you are well above 2000 rpms.

My R90S and R65 need to be on a charger sometimes, for this reason.

My older, 6V BMWs all live on the charger in rotation. The generators on those bikes are only *just* adequate for their headlights, and then only when they are running well above idle. (For example, my 1961 R60/2 has a generator that nominally puts out 45 watts, but has a 35 watt headlight, an 8 watt taillight and a a 20 watt brake light.) Their mechanical voltage regulators do not do a great job of optimizing the charge they put back into a battery, either.
 
Battery Tender...

Hi Darryl,

My introduction to BMW motorcycles was my '94 R100GS, which never had a problem with charging, just like my '04 GSA. However, I can understand that older bikes might not have charging systems that are as capable as these. Although, my '77 Honda CB750K7 is an exception!

Thanks for the response - happy riding those beautiful Santa Cruz mountains (even in the fog)! :)

Rob
 
Rob - I live in Wisconsin, where weather temps are changed by Mother Nature a half-dozen times a day, just for good measure!

The only time a charger and my battery are 'intimate' is over the winter months, where it hibernates down on the basement workbench.

Otherwise, with a ride each week (not even daily), all seems well. I think the BMW on-board charging system is adequate.

However, if left alone for too long (say 2+weeks), there may be trouble with today's more complex bikes (nothing more complex than a BMW!) - clocks, internal memories, alarm systems on passive stand-by....all contribute to a drain on a battery (which even if left alone without any 'load,' will still slowly lose power).

So while all of the bikes of my past (Suzuki's, Honda's, H-D's) did not require diligent charging, newer bikes are different animals from time to time.

Glad you get out daily on yours - an envious situation. :clap
 
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A charger/tender is good to have around if use use battery gear. Bikes? Yeah, I need it in the winter.
 
My bikes live in an insulated garage where the temperature ranges from around 40 in the winter to around 80-85 in the summer. I put a Battery Tender Jr. on them overnight about once a month in the winter. The battery in the 03 is the original battery and the battery in the airhead is a 10-12 year old Westco that I took out of my K75RT. When the battery went bad in the airhead 8 or 9 years ago, I put a new one in the K bike and put the old one in the airhead because the airhead needs less battery than a fuel injected ABS equipped bike. I think where you ride has a lot to do with how long a battery lasts. I live in the sticks and nothing is a short distance from me and a minute sitting at a red light seems like a long time. The battery stays fully charged.
 
Everything I have ever read on the subject and my own personal experience indicates that you should trickle charge your battery if it isn't being used, especially in the winter.
 
I find that battery tenders significantly extend battery life. With 6 licensed bikes in the garage it is not possible to exercise each one every day. When a bike goes in the garage, it's tender gets plugged in. (Each has an AGM or Odyssey battery).

The Odyssey battery in my R1100RS is 8 years old and still spun up the starter like new last winter in 30 degree temps and ran the grip heaters and Kanetsu liner with no problem. I like to think the tender had something to do with it.

Ron L
 
My K75RT is always pluged into an Accumate battery maintainer. Even though
it is pluged in, 95% of the time it is not charging, it is simply keeping an eye on
the voltage. I would think that a battery that is kept fully charged would last
longer than one that goes up and down.
 
Perhaps the Odyssey batteries are better at repeated-draw/short-charge cycles. But most other batteries sustain a short life with this type service, as you say, "The current bike I ride as a daily commuter, three miles to work and three mile back with the occasional ride to Half Moon Bay to eat lunch, is a 2004 R1150GSA that has a nearly three year-old PC680 Odyssey drycell motorcycle battery that is still going strong,"

Three miles to and back from work, especially if much of that is city streets, does NOT charge the battery adequately, even if it is on a BMW. That type of use and service duty cycle will normally shorten a battery life significantly, even in warm weather. Warm/hot weather starting can be just as hard on batteries as cool/cold weather. Even on a BMW, the charging system really doe snot adequately charge up the battery unless you spend about 1/2 hour at a constant highway speed at least a few times a week. Riding around town does NOT charge the battery or maintain a charged battery.

On my 94 RS, I used to have a min-1/2 ride on the highway at least twice a day, five days a week. The original Mareg battery lasted eight years in Wisconsin weather. Not so when I moved to Green Bay and work from my home. Now I keep the bike on a Battery Tender regulary, and the cheapo Toyo battery ($40) is on its fifth season. The expensive Westco battery before it failed early and suddenly.
 
Thanks for weighing in!

Hi all,

Thanks for all who responded - I value your inputs and appreciate your experiences! I see that a common thread here is that trickle chargers help batteries last longer, which is a very valid point. Living in a townhome community that has a common parking garage with no electrical outlets gives me little choice of whether or not I use one. However, I'm interested to see how long my Odyssey battery lasts, and, God willing, if I still remember this post when I need to replace it, I'll let you all know!

Happy riding! :)

Rob
 
+1 re Dale's point about using a battery 'maintainer' that "Even though
it is pluged in, 95% of the time it is not charging, it is simply keeping an eye on
the voltage"....

Because a constant 'trickle' charge over a long period of time can a destroy battery.
 
Excerpt from my soon to be released book...

Only 30% of batteries sold today reach the age of 48 months. Heck, in some cases you are lucky if you reach the 36 month mark. In fact 80% of all battery failure is related to sulfating build-up. This build up occurs when the sulfur molecules in the electrolyte or battery acid, become so deeply discharged that they begin to coat the battery's lead plates. Before long the plates become so coated that the battery dies or performs poorly. The causes of sulfating build-up are numerous.

ÔÇó Batteries may sit too long between charges. As little as 24 hours in hot weather and several days in cooler weather.
ÔÇó The battery is stored (on or off the bike) without some type of energy input.
ÔÇó "Deep cycling" an engine starting battery. Remember these batteries cannot stand a deep discharge. If you need to run your lights for long periods, put the battery on a charger. Do not let the battery discharge fully.
ÔÇó Undercharging of a battery to only 90% of capacity will allow sulfating of 10% of battery chemistry not reactivated by the incomplete charge cycle.
ÔÇó Heat of 100 plus degrees increases internal discharge. As the temperatures go up, so does the internal discharge rate. A new fully charged battery left sitting 24 hours a day at 110?? F for 30 days would most likely not start an engine.
ÔÇó Low electrolyte level can develop in wet cell batteries. When the batteries lead plates are exposed to air and they will immediately sulfate.
ÔÇó Incorrect charging levels and settings. Most cheap battery chargers can do more harm than good and having the wrong charger for your specific battery could be costly.
ÔÇó Cold weather is also hard on the battery. The chemistry when exposed to very cold weather conditions does not make the same amount of energy as a warm battery. A deeply discharged battery can freeze solid in sub zero weather.
ÔÇó Parasitic drain is a load put on a battery with the key left in the off position. Most often this occurs when an aftermarket device or ÔÇ£farkleÔÇØ is put on the bike, connected directly to the battery, and there is no ÔÇ£offÔÇØ switch to keep it from using power from the battery.

If you do get a new battery, keep it fully charged until you install it in your motorcycle. Once installed, keep it on the battery tender designed for your particular battery whenever you are not riding your bike. I know, I know, there are plenty of riders out there who are saying, ÔÇ£Well, I donÔÇÖt keep my battery on a charger and I seem to be doing just fine.ÔÇØ Yeah, and the guys who build these batteries are all wrong about their product. Keep your motorcycle on a charger at all times or ride your motorcycle almost daily and you will be rewarded with years of quality use.


just sayin'...
 
I ride one bike daily and the other a couple times a week.

In the winter they're both on "smart" battery chargers that top off the charge when needed. Even spending from late November to early April on the charger alone, my bike batteries last an average of 6-7 years. That's better than I usually do on a car battery!
 
My 2008 RT was built in 12/2007. OEM battery still going strong at 44 months. Optimate4 is plugged in except when the bike is moving, or when I'm on a trip where it's ridden each day.

Wife's 4-wheel 2007 BMW has its own Optimate4, and it gets plugged in when it sits undriven for anything more than two days. Replacing that battery is a major expense because the new battery has to be "registered" to the car electronically. Ouch.
 
+1 on Optimate 4

I only have one battery tender- an Optimate 4. I rotate it around on all 3 bikes, the generator, and the '65 Pontiac. I installed pig-tails on all, choosing not to use the Can-Bus option. I'm a believer.
 
I'd appreciate hearing your experiences and opinions!

One shouldn't need a battery maintainer unless the battery has an issue or there is a more than normal current drain in your electrical system while parked. As for the latter, owners should measure it...its simple enough to do.

The voltage of R1150 GS Adventure battery will go from 12.9V to 12.8V in a month of non-use. Considering the small drain, that is perfectly normal.

Batteries will tend to self discharge faster in warmer climates.

I use CTEK battery charger/maintainers for my motorcycles and car during the off season winter months or during long periods of storage. That is the only time you should need them.
 
Only 30% of batteries sold today reach the age of 48 months.


I guess I'm lucky.

The original battery in my car is 12 years old next month; the original battery in the previous car was 16 years old when the car was sold.

My original BMW flooded lead acid battery failed in the 9th year; others used for only a month a year, lasted 7 full years.

All of them flooded lead acid types. I don't have much use for AGM or Gel batteries.

You got to know how to treat them. :D
 
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