Topic: Leaving Battery Tender Connected in Garage?

[ironandtime]

Hi All,

I just got a 1.25A Deltran Battery Tender Plus to use for my Honda CB550. It has the ability to switch modes and cycle off once the battery is fully charged. It seems like a lot of folks just leave these chargers connected to the battery (while still on the bike) when the bike is sitting to keep a full charge on it at all times. My question is this: would doing this in a garage be a bad idea because of the gradual off-gassing? I suppose I could keep a fan on or something all the time to keep the air moving, but not sure how big a deal ventilation is with these trickle chargers. Thoughts?

[DH]

Id bet you could get away with it, but there's always a chance......I leave mine on till full charge, and unplug for a few days, plug in a few, re check. etc. 1.25 amps isn't a
lot to worry about, should'nt boil hardly all, but good to keep an eye on things anyhow. Maybe run a long vent hose to outdoors? And maybe disconnect and isolate both cables if you're leaving it in the bike and won't be riding for a while...just a thought.

[thirsty 1]

I've had 2 of them connected, full time while not riding, for over 10 years. I think you'll be ok.   

[lucky]

Hi All,

I just got a 1.25A Deltran Battery Tender Plus to use for my Honda CB550. It has the ability to switch modes and cycle off once the battery is fully charged. It seems like a lot of folks just leave these chargers connected to the battery (while still on the bike) when the bike is sitting to keep a full charge on it at all times. My question is this: would doing this in a garage be a bad idea because of the gradual off-gassing? I suppose I could keep a fan on or something all the time to keep the air moving, but not sure how big a deal ventilation is with these trickle chargers. Thoughts?

It must be for a car battery.
1.25 amps is a lot!!!

Most motorcycle battery tenders charge at around 300 mili amps.
Very low amount.

[dave500]

run it through a clock switch timer once its charged,set for like two hours a day or whatever?

[DH]

Hi All,

I just got a 1.25A Deltran Battery Tender Plus to use for my Honda CB550. It has the ability to switch modes and cycle off once the battery is fully charged. It seems like a lot of folks just leave these chargers connected to the battery (while still on the bike) when the bike is sitting to keep a full charge on it at all times. My question is this: would doing this in a garage be a bad idea because of the gradual off-gassing? I suppose I could keep a fan on or something all the time to keep the air moving, but not sure how big a deal ventilation is with these trickle chargers. Thoughts?

It must be for a car battery.
1.25 amps is a lot!!!

Most motorcycle battery tenders charge at around 300 mili amps.
Very low amount.

hmmm       my new, still in the box Everstart battery instruction sheet, says that after adding acid + a 1 hour standing time, the battery can be charged for 3-8 hours at 1.0 AMPS or for 2-6 hours at 1.5 AMPS........And my Schumacher charger/maintainer charges at 1.5 AMPS maximum, and stops when the battery is fully charged......

[Deltarider]

There's no need to have it hooked up all the time. All together tenders consume a lot of power worldwide and there's always a risk of fire. I know, I had one that started smoking within a day. If your insurance company finds out, you might have a problem. A well charged unused battery doesn't need more than a chargecycle in every 6 weeks.
If you allow me: they've calculated that in all of Europe two coalburning powerplants work around the clock just to generate the electricity for... our doorbelltrafos! I repeat: our doorbelltrafos, two coalburning powerplants. They only ring a few seconds a day (if at all) and all that time, 24 hours per day valuable energy is lost in... heat. It's the same with all these tenders.
Sidenote: there is so much what I would call overcare in this forum, it's epidemic.
This message is sent from meters below sealevel.

[TwoTired]

Batteries primarily outgas when some of it's cells become overcharged. Some of the gas is hydrogen, the other part is oxygen.    The outgassing is caused by electrolysis.  If your electrolyte levels drop quickly, it is usually because of outgassing, or very high temps which can make the water in the electrolyte evaporate quickly.

Automatic chargers are made to prevent overcharging, thus minimizing any outgassing electrolyte loss.  Good battery tenders only put enough power into the battery to overcome it's self discharge characteristics.  Batteries can vary with the amount of internal resistance they have and thus the heating effects during charge and discharge.

Anyway, the battery can't make the worrisome hydrogen without depleting the electrolyte levels.  As a test, monitor the electrolyte level and if it doesn't change there isn't much worry about explosions.

Another factor is that most garages are not really sealed, so as to vent off fuel vapors.  Particularly, if your car or bike shares it's space with a gas water heater,  building codes usually mandate an air exchange feature to keep gasses from collecting at high enough density to cause any issue.

So, if you have a new charger, monitor it at the beginning of use to gain confidence it is working correctly.  Once it proves worthy, then trust it to do the job safely while unattended.

The Deltran Tender is a three stage charger, from what I learned.  Stage one is bulk charge, where all 1.5 amps is available.  This charge rate tapers down to stage two which is an equalization, lower amperage rate, finally when the battery reaches a charge state where the voltage achieves 14.5 volts (this is near the threshold where outgassing begins), the current is again reduced and a lower "maintain" voltage level is delivered, which is just above the batteries own natural voltage level when full.

Long term, the only small drawback to this tender design (analysis of a few years ago) seems to be it's ability to switch back to high current if it senses the voltage drop too low.
This can happen when the electrolyte levels fall from other than overcharging means.  This can then become a death spiral for the battery.  Where there is not enough electrolyte to produce enough sense voltage to allow the charger to switch back to it's last low current stage, promoting more outgassing and eventual dehydration of the battery's cells.  So, you still need to check the battery fluid levels one a month or so.

[dave500]

must be a lot of ding dongs I mean doorbells in Europe?

[AJK]

As Delrarider has mentioned. Dont overthink it. Batteries need a bit of a punch to keep them healthy, so your 1.5A will be fine if your battery is in good order with the levels. My personal thoughts are that trickle charging over a long period of time will still allow the sulfation to continue which kills the battery long term. Some may disagree but I like to make the battery do some work as I think this helps get better life out of them.

6A charging (car charger) is supposed to be excessive for a bike battery. I know the book says this is too much, but thats what i've used for years without problems if the bike has been sitting for say 2 months. I think a 1.5A to 3A charger is probably about right for a motorbike battery.

If i sense/hear boiling, i take the charger off, but since it charges it up fairly quickly anyway, it doesn't take long to get up to charge.

Simple solution, run up the charger until full, then turn off the charger, unhook it & pack it away. Let the bike sit for as long as your not riding it, but take it for a ride every 4 weeks or so to re-punch it with the bikes charging system. Batteries like to be used. Simply riding your bike for say 30mins will get the charge up to where it should be. That way, you won't have to worry about the charger at all, unless you are charging a flat battery.

[Deltarider]

must be a lot of ding dongs I mean doorbells in Europe?

Hey Dave, I once had a girlfriend in London. Actually she was from Sierra Leone. She used to call me 'ding dong' on many occasions. Cute and intelligent as she was, she gave me nothing but compliments. The more compliments the more she smiled. Loved that woman.

[Jerry Rxman Griffin aka MuthaF'er]

Leave it hooked up. That's the purpose of a Battery Tender brand. It's a no worry piece of equipment. It has the circuitry to MAINTAIN the battery. It's not JUST a trickle charger! That's what it's intended for. It turns itself on and off depending on what the battery is doing. Never hurts to watch the electrolyte level when riding or not riding. 

Lucky needs to look up the Battery Tender brand of battery maintainer!

[grcamna2]

Leave it hooked up. That's the purpose of a Battery Tender brand. It's a no worry piece of equipment. It has the circuitry to MAINTAIN the battery. It's not JUST a trickle charger! That's what it's intended for. It turns itself on and off depending on what the battery is doing. Never hurts to watch the electrolyte level when riding or not riding. 

Lucky needs to look up the Battery Tender brand of battery maintainer!

 

[TwoTired]

6A charging (car charger) is supposed to be excessive for a bike battery. I know the book says this is too much, but thats what i've used for years without problems if the bike has been sitting for say 2 months. I think a 1.5A to 3A charger is probably about right for a motorbike battery.

A wet cell battery can take it's rated current up to about 80% capacity.  For a Cb550's 12AH battery, that's 12 Amps.  I also use a 6A dumb charger (Bought in 1964  ) for bulk charging a run down battery to about 13.5 -14V.  Then, I let the automatics finish peaking up the battery to full capacity and do some more de-sulfation.  The automatics or tender will do the same thing but, take a lot longer.
You can do initial charge with very high amps, equivalent to what a starter load is.  But, only during the initial bulk charge.  Beyond that, and electrolysis begins to occur, venting H and O2.
A wet cell battery can't really be peak charged with high amps to full capacity without losing some H2O.  The bike's charging system can finish the job during normal cruise operation.

If i sense/hear boiling, i take the charger off, but since it charges it up fairly quickly anyway, it doesn't take long to get up to charge.

Yes, we're after the same thing, saving time.

Batteries like to be used. Simply riding your bike for say 30mins will get the charge up to where it should be. That way, you won't have to worry about the charger at all, unless you are charging a flat battery.

I think this is exactly what Honda intended.  The bike's charging system isn't all that fast at recharge and depends on time in cruise mode to fully recharge the battery.  This seems to be more critical on the smaller bikes with weaker charging systems and smaller batteries.

You can apply math to the situation.  A crude approximation, is to take the battery's AH rating and divide it by the charge rate of the bike's charging system.  Check out the shop manual and note that it allots 1 amp battery charge rate whenever the engine is above ~ 2000 RPM.
At this rate, a discharged battery would take over 12 hours alternator operation to restore a 12 AH batter and over 14 Hrs to restore a 14AH battery.  The bike's Vreg should prevent any H20 loss if operating correctly (that's really it's primary job).  It's has the equivalent smarts as an automatic charger or Tender at protecting the battery from charge mode harm.

[dave500]

must be a lot of ding dongs I mean doorbells in Europe?

Hey Dave, I once had a girlfriend in London. Actually she was from Sierra Leone. She used to call me 'ding dong' on many occasions. Cute and intelligent as she was, she gave me nothing but compliments. The more compliments the more she smiled. Loved that woman.

that's not how to spell complaints delta.

[Deltarider]

Don't tell me she was in fact complaining... that can't be true... can it?... on the other hand...
Aaargh, I should never have trusted the #$%*!

[ironandtime]

Alrighty then - thanks for all the great responses! As is usual in this forum, you don't just get the simple answer to your question, but you also get a lot of related background info that makes it more of an education. And the sense of humor helps, too. You folks rock. Cheers, Matt

[grcamna2]

Alrighty then - thanks for all the great responses! As is usual in this forum, you don't just get the simple answer to your question, but you also get a lot of related background info that makes it more of an education. And the sense of humor helps, too. You folks rock. Cheers, Matt

Some of it is kinda 'adult education'..,hey ?! 

[AJK]

Yes TT. It is as you say. The 6A may be an initial in-rush current and handled by the battery during the bulk charge cycle when the battery is in need of charging, but as the battery charges up it will take less from the charger as its voltage rises and the difference in voltage between the charger and battery becomes less, therefore taking only what it needs in terms of current. Automatic tenders have a circuit built in that toggle between the charge and monitor (sense) states. So even though the charger may be rated at 6A, the electronics in the charger takes care of it, even though the battery is a smaller motorcycle battery.

The dumb chargers need to be manually timed to avoid boiling as you say.

If you start the bike using electric start, it might take around 10mins riding to get that used charge back into the battery. Like most bike/car manufacturers, they want the available power to be at the crank where the rider/driver can feel it, not going into the peripherals like the charging system. So the power used up in the charging system (sourced from the engine itself) is tuned in a way to do the job & no more. This is by controlling the current fed into the field coil (via the vreg).

Regarding the vreg, if its tuned right (screw is set correctly), it acts just as a tender as your've mentioned. It is good to periodically check that the vreg is functioning correctly according to the book.

Here is an interesting article on battery care.

http://www.flyingbeet.com/electricg/batteries.html

Regarding the tender, i didn't explain it properly in my previous post, but it had to do with promoting sulfation if you just kept it on the tender forever. As i mentioned, batteries need a punch & need to be used. They like to be worked. Here is an excerpt taken from the yuasa site.

http://www.yuasabatteries.com/motor_battery.php

"So, I can just set it and forget it, right? Well, not exactly. For one thing, you need to monitor the battery occasionally for correct fluid level (unless you own a sealed battery). Another problem is that of exercising the battery. Even if held at 13 volts, the unwavering voltage will allow the battery to eventually begin to sulfate. With most of these units, I recommend that you unplug the charger at least once every 60 days during seasonal storage. Allow the battery to rest for a couple of days, and then plug the charger in again. One charger that I’m aware of, the 1.5 amp Yuasa unit, has a feature found mainly on the aforementioned high priced RV chargers. It drops off the float charge and sends the battery through a complete new charge cycle every 28 days, thus eliminating the need to do that manually. There may be other motorcycle units that do that, but I’m not aware of any."


To me, leaving battery tenders on forever, is just another transformer in the house getting hot for no reason, so i top them up as necessary, which is not that often in practice. I find that a top-up is no longer than about 20mins anyway on a bike battery and I'm usually around to unplug the unit & pack it away.

[Airborne 82nd]

I like Dave's idea of a timer but I'm sure someone will have a problem with a clock running all the time Now what can we put on to stop the timer. Oh I got it a Rube Goldberg machine.

[TwoTired]

Yes TT. It is as you say. The 6A may be an initial in-rush current and handled by the battery during the bulk charge cycle when the battery is in need of charging, but as the battery charges up it will take less from the charger as its voltage rises and the difference in voltage between the charger and battery becomes less, therefore taking only what it needs in terms of current. Automatic tenders have a circuit built in that toggle between the charge and monitor (sense) states. So even though the charger may be rated at 6A, the electronics in the charger takes care of it, even though the battery is a smaller motorcycle battery.

The dumb chargers need to be manually timed to avoid boiling as you say.

I know what you mean by the dumb chargers cutting back on charge current as they restore batteries.  This type is usually a constant voltage type, rather than constant current.

As you state, they can only supply their largest currents when the voltage differential between the battery and the charger is great.  As the battery's voltage comes up during charge, the differential lessens, and therefore less current is delivered.   This is because the battery's internal resistance remains constant at any charge state.  Current then becomes directly proportional to the voltage differential (ohm's law).  As you say, you have to manually time/observe these chargers to avoid damaging the battery.  Because even when the battery gets full, it will still supply about an amp, which is enough to sustain electrolysis, after the battery is already fully charged.

Of note, on a car battery (much higher capacity) these same chargers revert to near tickle charge rates when the battery is full.  So, close monitoring is not as essential.  But, on a smaller MC battery, you gotta be more careful.   It's a matter of smarts in the charger vs. smarts in the operator.

Battery chargers are as varied in features and function, and there are motorcycles in creation.

Cheers, 

[grcamna2]

The YB12A-A batteries get lot's of use and abuse and have over the years;I'm thinking of ordering a Scorpion AGM equivalent to this model battery;do any of you have any AGM charging instructions ? 

[xsmooth69x]

i didnt read any of the thread after twotired since i was too tired to read any more but i can say this

i had a new battery tender, didnt watch it since i thought pshhh its new and awesome..... totally didnt work a month or 2 i noticed my battery was bone dry......

so time for a new battery 

and them im going to start a thread about batteries without the filling liquid stuff like a car battery or a lawn mower batter or any other batter other then motorcycles that you have to fill!?!

this thread will probably be asking something that another thread did like 2 years ago but will be a 2014 awesome upgrade in battery technology that i will pay a premium for but not have a battery that boils, makes some crazy gas or a battery tender will work on with this awesome new 2014 of epic new battery technology. i mean come on the tesla runs on batteries (not that i would every buy one or a prius)

[TwoTired]

AGM batteries are rather sensitive to overcharging.  The glass mats inside are minimally soaked so as to keep the electrolyte in place.  When these outgas, it effects capacity.  And since you can't normally restore the fluid levels, it's permanently lost.

Smart chargers are pretty essential for recharge off the bike.  AGMs are expected to sit for long periods without "tending".  Don't charge them unless it's measured voltage demands it. imo.

[grcamna2]

AGM batteries are rather sensitive to overcharging.  The glass mats inside are minimally soaked so as to keep the electrolyte in place.  When these outgas, it effects capacity.  And since you can't normally restore the fluid levels, it's permanently lost.

Smart chargers are pretty essential for recharge off the bike.  AGMs are expected to sit for long periods without "tending".  Don't charge them unless it's measured voltage demands it. imo.

TT,
Do most AGM battery manufacturers/marketers have those charging specs available ?
                     Thanks in advance for your help 

[TwoTired]

TT,
Do most AGM battery manufacturers/marketers have those charging specs available ?
                     Thanks in advance for your help 

I can't really answer that as I don't know them all.

Usually, the operational technology is not all that different from a flooded cell battery.  But, different plate metals/alloys ARE possible.
AGM stands for Absorbed Glass Mat.  These mats fit between the plates and just enough liquid electrolyte is introduced to wet the mats which have contact the plates.  The electrolyte is held in place largely by capillary action and inherent adhesion properties, so it doesn't spill.  My AGMs get charged from smart providers of power, either the vehicle on board voltage regulator or an automatic charger with a charge rating compatible with the capacity of the battery being charged.

The charge rating is all about the C rating of the battery.  Say the battery has a 12AH rating, this is the C rating or the maximum safe continuous discharge rate of the unit.  (It's more complicated than this, actually.  But, this is close enough for now).  Normal safe and prolonged charging is done at 1/10 C or about 1.2 Amps in this case (until outgassing is observed).  Charge maintenance of a fully charged battery is usually at a C/100 rate, in this case 0.120 A or 120ma.  This latter charge rate is considered not enough to cause the battery to overcharge/ overheat/ outgas.
3 stage chargers usually cover most of the charge bases.  But, there are 5 stage chargers as well as chargers that adjust their Voltage sensing in accordance with temperature changes.  Cold, fully charged batteries show a lower voltage than Hot fully charged batteries.  If your charger doesn't automatically compensate for temp, you risk undercharging your battery in a cold winter garage with resultant sulfation.

All this is tempered with the standard internal resistance of the battery in question (relates to battery plate materials and assembly construction), which is why you really SHOULD follow the manufacturer's recommendations regarding charge conditions.  If the battery has higher internal resistance, the C/100 rate is augmented to allow for that resistance or loss of charge power for the plate/electrolyte absorption.

Hope I didn't make your head spin.   
There's a lot of info out there about batteries and chargers.  So, it's hard to make it simple without specifics.

[grcamna2]

Ok TT,
I understand the 1/10th,and just learned from what you said about the temp. of the battery being charged(what temp. is optimal?) but I'm interested in reading the battery voltage and seeing when it's necessary to begin charging it i.e. the minimum voltage before a good charge.I would have liked an exact way of knowing when an AGM battery wanted to be charged.I'd also like to know when it's reached full charge and what voltage would be optimal.
I sold a few Yuasa AGM's and they had very good instructions included which took the guess work out of it,but that was a few years ago and I realize that there are many different companies selling them now.

[Stev-o]

I have a tender but don't see the need of keeping it hooked up at all times.

[78 k550]

I leave on on all the time. gell cell.
Goldwing battery's say can take a trickle charge of 2 amps. I can use my car charger on it.
small battery tender is 750ma or 900.

Paul

[dave500]

I don't like things left plugged in,anything can over heat and catch fire especially cheap stuff like timers and chargers,properly looking after a battery is another labour of love,if you flip a few bikes the old battery goes into the seller and the keeper gets the new one over and over,i like lead acid batteries,i used to be the gold coast 24 hour "holler for a marshall"guy over twenty years ago.

[AJK]

Nothing wrong at all with lead acid batteries. Sure they have the weight, but extra weight helps you when your trying to break the sound barrier. They have been around for about 1000 yrs as well.

Actaully, lead acid batteries have an excellent recycle regime. Even though your dealing with toxic/harmful materials, if they are recycled properly through a proper depo, they are recycled in a highly efficient manner with little environmental waste. The lead goes one way, the plastics another. Not sure what happens with the acid? Perhaps it gets neutralised and made environmentally friendly.

I haven't looked into gel-cells much, but they must behave different (better??) on a tender long term? I guess they must because they are used in a lot of high end communications equipment thats always on a power source 24/7. So during a power outage, they take over. So i guess they must work better for continual tender charging.

[dave500]

I think gell batteries are like ethanol fuel,it aint quite right?

[TwoTired]

I understand the 1/10th,and just learned from what you said about the temp. of the battery being charged(what temp. is optimal?)

A given charger should have a specification for the temperature at which its other specifications are derived.  This is typically 70 F.
I've added a chart here of what the typical AGM likes to get vs. temperature.
I got the caution relationship backwards in my earlier post and will go back and correct it.

but I'm interested in reading the battery voltage and seeing when it's necessary to begin charging it i.e. the minimum voltage before a good charge.I would have liked an exact way of knowing when an AGM battery wanted to be charged. I'd also like to know when it's reached full charge and what voltage would be optimal.

14.4 V should be the trip point for switch from equalization charge to float charge.  And float charge voltage should be 13.8V.  Note these voltages are while being fed power by a charger.  The Voltage status for a battery rested and unloaded are the same as for any other lead acid battery.  Second chart below.

Perhaps you are asking about open circuit battery voltage over temperature?  See last chart.

In the end, an AGM is still Lead acid technology, meaning the status voltages are the same as the flooded cell types.  However, just because the electrolyte is somewhat immobile in an AGM they are sensitive to overcharge issues.  If your Vreg or charger tries to maintain the battery at 14.4V in hot weather, it will overcharge an AGM on long cruises or long durations in hot weather.

REF:
http://batteryuniversity.com/learn/article/absorbent_glass_mat_agm
http://batteryuniversity.com/learn/article/charging_the_lead_acid_battery


Hope this helps.

[Vinhead1957]

I leave tenders on all my bikes(3). All winter !   I believe they extend my battery life.   2005 second battery 2007 second battery

[grcamna2]

ok TT,  Yes,that does help.
Temp. makes a big difference in the resting state charge of the battery voltage or specific gravity reading ? and the battery(AGM only?) is more prone to overcharging when the temp. rises ?