When should one consider a battery tender?

[EricJRW]

I asked the question here http://www.bmwmoa.org/forum/showthre...d=1#post669147, but then thought to create a new thread.

Basically, at what point is a battery tender a good idea?

I just replaced my battery (it was almost 7 years old), and wonder if that's good or if it would have lasted longer if I had kept it on a tender (and if I should consider a tender for the new battery)

Thanks in advance,

Eric

[Bob T]

Without trying to sound like a smart *ss....

The time to consider a battery tender is when one buys a motorcycle...

It is just good for the battery...

[EricJRW]

Well that's what I was thinking too, but then as I was standing at the counter buying the battery and pricing the tender another customer said "Just ride it.", which also makes sense. So what is the "not enough riding point" to make a tender worth while?

If I go on vacation for a week or two, is that long enough to justify a tender?

Would it better if the battery was just always on the tender?

I'm starting to think 7 years was a pretty good life for this battery, so I'm not even sure if a tender would have bought me anything.

[Bob T]

Good point...

"Just ride it" is not an option all year up here where I am...I guess in Texas it is...

I also have two registered bikes at the moment and have had more in the past, so I just think it is normal to have one for every bike.

[osbornk]

Well that's what I was thinking too, but then as I was standing at the counter buying the battery and pricing the tender another customer said "Just ride it.", which also makes sense. So what is the "not enough riding point" to make a tender worth while?

If I go on vacation for a week or two, is that long enough to justify a tender?

Would it better if the battery was just always on the tender?

I'm starting to think 7 years was a pretty good life for this battery, so I'm not even sure if a tender would have bought me anything.

I have a Battery Tender Jr. for both of my bikes. I don't leave them on the bikes all the time. I put them on overnight every three or four weeks or until the light turns from red to green. The airhead's battery is over 11 years old and the 03 oilhead still has the original battery. I think the most important thing is to keep the battery at a moderate temperature. Mine lives in an unheated but insulated garage. The temps rants from around 40 to the low 80s at most.

[flat_twin]

I have a Battery Tender Jr. for both of my bikes. I don't leave them on the bikes all the time. I put them on overnight every three or four weeks or until the light turns from red to green. The airhead's battery is over 11 years old and the 03 oilhead still has the original battery. I think the most important thing is to keep the battery at a moderate temperature. Mine lives in an unheated but insulated garage. The temps rants from around 40 to the low 80s at most.

Wow, I know what would happen to me if I said anything out loud about having an eleven year old battery! You better start shopping for a new one now if Murphy was listening!

[JDOCKERY132445]

I ride to work; but when I park my bike in the garage, it gets plugged in to the tender. It is a habit that pays off.

[PGlaves]

Without trying to sound like a smart *ss....

The time to consider a battery tender is when one buys a motorcycle...

It is just good for the battery...

Maybe. If the float voltage and current are both right for that specific battery. I just bought a new battery for my F650. The battery came with a page of notations and numbers about charging the battery.

I've had the best luck with bike storage when I don't keep the automatic chargers on all the time. I give stuff a shot for 24 hours every couple of weeks. I have three or four chargers (depending) plugged into a power strip. I just turn the switch on and off to start and stop the charging.

[tommcgee]

The AGM batteries don't lose charge as quickly as the traditional lead/acid bike batteries.

I've used one of my electronic test bench power supplies to charge batteries for the last 40 years or so, but the battery tenders are a whole lot easier to carry out to the driveway when one of the bikes needs a boost. I bought a couple of them a few years ago when they were on sale.

[EricJRW]

I like the concept of using it for period maintenance.

I borrowed a tender from a neighbor and he cautioned me that this was the accepted "best" tender as others have the habit of burning up batteries. I suspect this has to to with matching the specs of the charger to the battery, but there could also be charger failures resulting in ruined batteries. So I think I will buy one, but only use from time to time.

Thanks for the comments.

Eric

[bkwags]

I live in WI and don't ride very often during the winter. So I have a tender for my bike. I would think if you ride more than 50 miles per month you would not need one. Also, if the weather does not get too cold for too long that also lessens the need.

Tenders keep the charge up, during periods of little or no use. Which saves the plates inside. They are also an effective way of keeping batteries from freezing and cracking in very cold climates.

7 years on a battery, sounds like heaven to me. I only get 3-4 on average. I would save the money and use it to buy more gas to ride as often as possible.

If you do get a tender, make sure to match it to the type of battery that you have. They are no longer all the same.

[GlobalRider]

The AGM batteries don't lose charge as quickly as the traditional lead/acid bike batteries.

True and that is fine if a fully charged AGM battery is left stored without anything connected to it, but the self discharge of an AGM battery ends up being a very small percentage of any drain current when the battery is connected.

[GlobalRider]

Basically, at what point is a battery tender a good idea?

If you use your motorcycle regularly, you do not need to use any charger. Only if the drain current is such that your breaks between rides drains the battery to say 12.6 V would you need a battery maintainer.

I use one during winter storage.

I use a CTEK 3300 which has an AGM/cold weather mode as well.

[EricJRW]

Interesting point about checking the voltage...

Going to have to play around with that. Still undecided on whether to tender or not.

Do you think sitting for a week with no tender is bad? I'm hoping to make that my worst case scenario, though 2 might be tops (long vacation).

Thanks

[GlobalRider]

Do you think sitting for a week with no tender is bad? I'm hoping to make that my worst case scenario, though 2 might be tops (long vacation).

Actually, having a battery sit on a battery maintainer isn't all that good for it. One is better off giving a battery a periodic charge.

I use my battery maintainer to charge the battery on my R1150 GS Adventure and when its on float, I disconnect it.

A day later my battery voltage is 12.9V, two weeks later it might drop to 12.8V and stays at that for till the third week.