Battery Tenders

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850cmndo

850cmndo

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So now that the bike is put to bed for the winter, I'm wondering if anyone has left a Tender hooked up for the duration versus removing the battery and putting it in a warm spot. My shop is anything but warm on the -XX degree mornings coming up in the near future. Just wonderin'.
 
850cmndo said:
So now that the bike is put to bed for the winter, I'm wondering if anyone has left a Tender hooked up for the duration versus removing the battery and putting it in a warm spot. My shop is anything but warm on the -XX degree mornings coming up in the near future. Just wonderin'.
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To a certain extent it depends on what battery you have as to which battery tender you choose and if you should use one.(I always would since even the best bateries can lose 1%-4% per month due to self discharge.
To be honest there is a lot of confusion arround at preseht regarding 'GEL' 'AGM' and standard LA flooded batteries.I have used a tender for one of my bikes and it was fine (Moto Guzzi V11) I would remove it from the bike and put it on a tender anyway. I spent a week looking at the isssues regarding the new modern type of maintenance free batteries with some very worrying information out there reagrding suitable tenders. (Optimate, Accumate, Cirtek,YUASA etc.
 
I found that even a tender can boil out an acid filled battery if left on for a while. But...an AGM can be left on indefinately with no problems. I have roughly 18 vehicles I keep on battery tenders, they each have their own. Bikes / jetskis on Juniors, Cars and UTV on the regular tender. Many for months at a time for a Michigan winter. For bikes the batteries have lasted as long as 8 years this way. I ride a bike and when done hook it back up to the tender, even if it will only be a week or so. AGM's just won't boil the water out and are fine this way.
 
lrutt said:
I found that even a tender can boil out an acid filled battery if left on for a while. But...an AGM can be left on indefinately with no problems. I have roughly 18 vehicles I keep on battery tenders, they each have their own. Bikes / jetskis on Juniors, Cars and UTV on the regular tender. Many for months at a time for a Michigan winter. For bikes the batteries have lasted as long as 8 years this way. I ride a bike and when done hook it back up to the tender, even if it will only be a week or so. AGM's just won't boil the water out and are fine this way.
Click to expand...

Actually AGM and GEL batteries are as far as I am aware are all VRLA (Valve Regulated Lead Acid) batteries and are extremely susceptible to over charging since if they are charged too quiclky or at too high a voltage do in fact lose hydrogen which cannot be replaced as the battery is sealed. I discovered this after fitting an aftermarket GEL to my brothers BMW R1100s which failed after 7 months. This was because the Voltage Regulator was putting out too high a voltage for the GEL.The original was a standard 'flooded' LA battery.

If anyones interested read these...http://www.vonwentzel.net/Battery/01.Type/index.html
http://www.accumate.co.uk/MFBatteries.htm
http://www.landiss.com/battery.htm

these are just a few:-(
 
Since we're talking about british bikes/commando...probably with zener diodes, then the battery should always be disconnected from the general harness (connected to Zener) or the battery tender will just continue to bleed through to ground once the zener boundry voltage is achieved.
:roll:
http://atlanticgreen.com/images/zener.gif
 
My Yuasa charger goes into float before the battery reaches the zener level. I have left it on AGM batteries for a year or more. A couple other maintainers I have will eventually get that high. Jim
 
I use a Junior plugged into the garage-door-opener light, every time the door goes up or down the Tender runs for 6 minutes.

Seems to work great.

Vince
 
I like the garage opener idea. I'm running a sealed unit versus gell. Guess I'll see what happens. My thanks.
 
I just rotate though my batteries charging them up every month or so during the winter. No need to leave them on the tender all the time. My AGM batteries will hold a charge easily for 3-4 months while the lead-acid ones discharge in a few months.
 
comnoz said:
My Yuasa charger goes into float before the battery reaches the zener level. I have left it on AGM batteries for a year or more. A couple other maintainers I have will eventually get that high. Jim
Click to expand...

Which YUASA charger are you using the 900ma, 2A or 4A version? (Going to dump my Optimate.)

Cheers Paul
 
What's snow? I ride year round here and it was 40 degrees here today. Celsius.

Life's tough.
 
Fullauto said:
What's snow? I ride year round here and it was 40 degrees here today. Celsius.

Life's tough.

maybe but who's got all the snakes, crocs, sharks,poisenous,spiders,octopus,jelly fish,and flies oh and i forgot cane toads !
snow melts !!! 8)
i rest my case
Click to expand...
 
Unclviny said:
I use a Junior plugged into the garage-door-opener light, every time the door goes up or down the Tender runs for 6 minutes.

Seems to work great.

Vince
Click to expand...
That might be a good technique if using a trickle charger - they put out the same amperage regardless of a battery's state of charge. In fact, it would be a really good idea with that type of charger, because it would prevent damage due to over charging. But if using a 3-stage maintainer (smart charger) like the Junior, there are a couple of flaws (IMO) with the garage door opener trick. First one is that the Battery Tender Junior is so weak, it takes a lot longer than most battery maintainers just to get a battery fully charged. Six minutes at random intervals isn't likely to get the job done effectively. That battery will never be brought above gassing voltage, so it'll begin to sulfate much sooner than if you just left the Junior turned on all the time. Another issue is that you've paid for a device that "knows" when the battery is fully charged. Then it keeps it at a lower voltage level that will keep it from discharging, yet not a high enough voltage to cause it to overcharge - yes, flooded batteries will need topping up occasionally. So it wasn't designed to be effective the way you're using it, and that may become apparent sooner than you'd like. I'm not criticizing you - just trying to enlighten...
http://www.yuasabatteries.com/motor_battery.php

Stu
 
plj850 said:
lrutt said:
I found that even a tender can boil out an acid filled battery if left on for a while. But...an AGM can be left on indefinately with no problems. I have roughly 18 vehicles I keep on battery tenders, they each have their own. Bikes / jetskis on Juniors, Cars and UTV on the regular tender. Many for months at a time for a Michigan winter. For bikes the batteries have lasted as long as 8 years this way. I ride a bike and when done hook it back up to the tender, even if it will only be a week or so. AGM's just won't boil the water out and are fine this way.
Click to expand...

Actually AGM and GEL batteries are as far as I am aware are all VRLA (Valve Regulated Lead Acid) batteries and are extremely susceptible to over charging since if they are charged too quiclky or at too high a voltage do in fact lose hydrogen which cannot be replaced as the battery is sealed. I discovered this after fitting an aftermarket GEL to my brothers BMW R1100s which failed after 7 months. This was because the Voltage Regulator was putting out too high a voltage for the GEL.The original was a standard 'flooded' LA battery.

If anyones interested read these...http://www.vonwentzel.net/Battery/01.Type/index.html
http://www.accumate.co.uk/MFBatteries.htm
http://www.landiss.com/battery.htm

these are just a few:-(
Click to expand...

By definition of this post we are talking tenders, so they should NOT overcharge anything. Otherwise the statement above is true, one must be careful in trying to breing a dead AGM up to charge, trickle is best.
 
plj850 said:
Which YUASA charger are you using the 900ma, 2A or 4A version? (Going to dump my Optimate.
Click to expand...

For motorcycle batteries you should stay around 1 amp or lower or you will boil them. My Tender Junior is 0.75 A I believe.
 
plj850 said:
comnoz said:
My Yuasa charger goes into float before the battery reaches the zener level. I have left it on AGM batteries for a year or more. A couple other maintainers I have will eventually get that high. Jim
Click to expand...

Which YUASA charger are you using the 900ma, 2A or 4A version? (Going to dump my Optimate.)

Cheers Paul
Click to expand...

Actually I don't know. I have had it since the mid 80's and it doesn't look like any they have available now. I can no longer read the tag but I remembered it as being 1 amp output. It is shaped like a flattened hexagon.

I also have 3 Battery Tenders but I don't leave them plugged in very long. Jim
 
lrutt said:
By definition of this post we are talking tenders, so they should NOT overcharge anything.
Click to expand...
Correct. They won't. A VRLA battery will never out gas due to being charged with a motorcycle battery maintainer, though they certainly can if a high powered charger is used, or if a trickle charger is left on all the time. The flooded style batteries that need topping are just reacting the same way they do when the charging system is active. They're not being overcharged by the battery maintainer. Any voltage above the battery's resting voltage will accelerate electrolyte loss in a flooded battery. And that's probably the best argument for installing sealed batteries.

Stu
 
dynodave said:
Since we're talking about british bikes/commando...probably with zener diodes, then the battery should always be disconnected from the general harness (connected to Zener) or the battery tender will just continue to bleed through to ground once the zener boundry voltage is achieved.
:roll:
http://atlanticgreen.com/images/zener.gif
Click to expand...
That's an excellent point - depending on the zener's boundary voltage and the maintainer's maximum output voltage. With the single zener attached to the battery negative cable on the pre-MKIII systems, I'd bet you're right.

I just did a small experiment with my bike and maintainer because of your post. But - this is a MKIII system, where the 2 zeners are connected to the stator's AC output wires at the rectifier. So, there's a rectifier diode between each zener and the battery's negative cable. Those diodes have a forward voltage drop of around a half volt, so the zeners will never see the full charger output voltage and won't begin conducting. I turned on the headlamps for 5 minutes to drain the battery a bit, then connected the maintainer and monitored battery voltage during charge. I did this once with the zeners connected, and once with them disconnected. In each case, the voltage went to 14.28 before the maintainer dropped into float mode holding 13.6 volts. Someone should try this with a pre-MKIII system to see what happens. It would be interesting to know.


Stu
 
I've used "Juniors" on several motorcycles and ATV's for many years now. I leave them on all the time with no problems. Battery life has been extended noticeably. Highly recommended for vehicles that sit for weeks and sometimes months between uses.
 
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