Battery Maintainers in (very) cold temperatures

[MtlBen]

I will store my RT in a non-heated garage for the winter. I am planning on leaving the battery on a battery maintainer during storage.

I have seen some units from unknown manufacturers that advertize that their product will work in extreme cold temperature.

As I want to stick with brand names, does any one knows how a "Battery Tender Junior" or a "Yausa 900mA HotShot" would perform in our -30 winter temperatures ?


...Ben...

 

[NancysToy]

I expect any of them will work. I would not use the Battery Tender Jr. The lower output of that unit might not keep the battery up as well in those cold temperatures. I'd shoot for something with max output in the 1.25-1.5 amp range. That being said, The on/off nature of a battery maintainer may not be adequate to keep a battery from freezing in -30 C (-22 F) temps. I'd remove the battery and bring it inside for the winter, before putting it on the maintainer. A frozen or slushy battery is useless, come Spring.

 

[pro10is]

Typical automotive/Motorcycle batteries will self discharge even if disconnected. Eventually they will freeze in very cold weather as the charge dissipates. Once a battery is frozen it is history.

In addition a battery will begin to sulfate when not at a full charge. Sulfation will occur at any temperature (warmer is actually worse) and will eventually weaken the battery. So it's important for the health and long life of a battery to keep it at a full charge in season and off season.

The best way to do that is to buy a quality voltage regulated float charger and keep it at 100% charge at all times. You can attach a quick connect charging lead to your battery to simplify this, many chargers include one.
A quality regulated charger is a good investment, the microprocessor based chargers are especially effective and efficient. Never use an unregulated charger, overcharging is equally as bad.

You can get many years additional use out of your battery if you keep it fully charged at all times.

 

[Adirondack Mik]

I ran a HD 750 mh set up on my HD for 9 years with no problems. For 8 years I lived in Saranac Lake, NY. I finally had to replace the battery on the 8th year, I figure I had pretty good service out of the charger and use it on Rar's Spyder now. Happy day after Thanksgiving Ben. :yes:

 

[Bob Denman]

I'd remove the battery and bring it inside for the winter, before putting it on the maintainer. A frozen or slushy battery is useless, come Spring.

:agree: That would certainly be the safest course of action! :thumbup:

 

[NancysToy]

Typical automotive/Motorcycle batteries will self discharge even if disconnected. Eventually they will freeze in very cold weather as the charge dissipates. Once a battery is frozen it is history.

In addition a battery will begin to sulfate when not at a full charge. Sulfation will occur at any temperature (warmer is actually worse) and will eventually weaken the battery. So it's important for the health and long life of a battery to keep it at a full charge in season and off season.

The best way to do that is to buy a quality voltage regulated float charger and keep it at 100% charge at all times. You can attach a quick connect charging lead to your battery to simplify this, many chargers include one.
A quality regulated charger is a good investment, the microprocessor based chargers are especially effective and efficient. Never use an unregulated charger, overcharging is equally as bad.

You can get many years additional use out of your battery if you keep it fully charged at all times.

Unfortunately, the chargers (maintainers) do not keep a battery at full charge continuously. That is a common misconception. They cycle on and off, kicking in each time as the battery voltage drops to a predeterminted level, then bringing the voltage up again. You could provide a continuous low current charge, but the overcharging would be hard on the battery (and boil a vented battery dry). Best to yank it out and bring it inside...or heat the garage. JMHO

 

[pro10is]

Unfortunately, the chargers (maintainers) do not keep a battery at full charge continuously. That is a common misconception. They cycle on and off, kicking in each time as the battery voltage drops to a predeterminted level, then bringing the voltage up again. You could provide a continuous low current charge, but the overcharging would be hard on the battery (and boil a vented battery dry). Best to yank it out and bring it inside...or heat the garage. JMHO

Gotta disagree with you here Scotty. Years ago this was true but not today. Quality multi-stage, microprocessor based float chargers (now common and inexpensive) are very gentle to batteries, even more so than the Spyder's charging system in normal operation. They will not overcharge, boil off, or cause any appreciable harm to the battery. Most importantly they will prevent sulfation which is eventually what kills most batteries. If you just bring a battery inside where it's warm, the battery will continually self discharge and sulfate. The warmer it is the greater the sulfation rate. By the time Spring rolls around the neglected battery will be sulfated enough to lower its service life. Some chargers include de-sulfating modes to attempt to reverse the damage somewhat, but once the effects of sulfation accumulate, the battery is permanently weakened and its service life and effectiveness reduced. Severe sulfation will eventually cause battery failure.

A quality multi-stage, microprocessor based float charger will constantly monitor your battery's voltage. When it senses the charge is slightly reduced it will very gently trickle charge it. As the battery approaches a full charge, the charging rate will be more and more reduced. The battery will never be over charged or boiled as was the case with legacy "dumb" brute force chargers.

If you don't want to keep your battery float charged, at the very least keep it cool. Sulfation increases significantly with temperature so keep your battery as cool as possible, but no colder than 40 degrees F. Store it in the coolest location you can but where it will be protected from freezing. Do not leave unused batteries in a warm place and never let them become hot (I've seen people store them near wood stoves thinking warmer is better).

Batteries were designed to stay fully charged as they are in normal operation. If you don't keep them fully charged you may reduce their service life several years.

 

[NancysToy]

I agree that they are gentle to batteries. They are absolutely the only kind to use! The problem is that they don't keep a battery continuously at full charge, as you said. They wait until the voltage drops to a set level, then begin their cycles again. The best ones don't allow the battery to drop way down, so they don't do the full cycle nearly as often, but they still cycle in on some sequence. The only way to stay at 100% all the time is to use the old style chargers, which are unsuitable for many small batteries.

I don't know what temperature causes the acid solution in a battery to start to form ice crystals, or what the relationship is to the state of charge. I'm sure I could look it up, but I'm lazy, I guess. At any rate, at temps like -30 C (-22 F), I would sure not risk leaving the battery outside if I could help it, maintainer or not. We get several power outages here each year, and that could spell the end for a battery on a charger that faced arctic cold temps.

 

[MarkLawson]

I have no idea if this will help in your extreme temps, but it might. If you put a cover over the Spyder, you might be able to place a shop light under the cover, somewhere where it could not burn anything when it gets hot. I might supply enough trapped heat under the cover to keep the battery temperature at a reasonable level.

 

[pro10is]

I agree that they are gentle to batteries. They are absolutely the only kind to use! The problem is that they don't keep a battery continuously at full charge, as you said. They wait until the voltage drops to a set level, then begin their cycles again. The best ones don't allow the battery to drop way down, so they don't do the full cycle nearly as often, but they still cycle in on some sequence. The only way to stay at 100% all the time is to use the old style chargers, which are unsuitable for many small batteries.

I don't know what temperature causes the acid solution in a battery to start to form ice crystals, or what the relationship is to the state of charge. I'm sure I could look it up, but I'm lazy, I guess. At any rate, at temps like -30 C (-22 F), I would sure not risk leaving the battery outside if I could help it, maintainer or not. We get several power outages here each year, and that could spell the end for a battery on a charger that faced arctic cold temps.

Practically the best that can be done is to keep the battery at as near a full charge as possible and the microprocessor based float chargers will do that regardless of the ambient temperature as long as the battery is under no external load. I live in Vermont and we can see temperatures of -25 degrees F for a week. This is not a problem for a fully or near fully charged battery:
[TABLE="class: grid, width: 500"]
[TR]
[TD="align: center"]Charge Rate
[/TD]
[TD="align: center"]Freezing Temperature (F)*
[/TD]
[/TR]
[TR]
[TD="align: center"]100%
[/TD]
[TD="align: center"]-77
[/TD]
[/TR]
[TR]
[TD="align: center"]75%
[/TD]
[TD="align: center"]-35
[/TD]
[/TR]
[TR]
[TD="align: center"]50%
[/TD]
[TD="align: center"]+10
[/TD]
[/TR]
[TR]
[TD="align: center"]25%
[/TD]
[TD="align: center"]+5
[/TD]
[/TR]
[/TABLE]
* Note: The electrolyte solution may become slushy at about 5 degrees F higher temperature than the Freezing Point.

When my car is outside in -25 degree F weather I don't worry about the battery freezing as long as I know the battery is reasonably charged.

If you keep your Spyder battery at or even nearly fully charged in your garage on a quality, microprocessor float charger it's in no more danger than the batteries in your cars in the same garage even if the temperature occasionally drops really, really low or even if the power goes off for a couple of days. If you get a really severe cold snap or extended power outage you can then bring the battery indoors for a while if you're concerned.

If you're not comfortable with this you can bring the battery indoors all winter but then you shouldn't use a charger because there is the remote possibility of explosive gasses when charging. But if you store your batteries indoors with no float charge be prepared for battery failure years sooner then its normal service life as it will become sulfated.

 

[NancysToy]

Thanks for the electrolyte freezing table. It appears that the critical point is around 75% charge. As long as the maintainer specs indicate that it will kick in above that point, freezing shouldn't be an issue unless the power fails. That problem is worrisome. I would not want to chance it, but some might. I agree with the BRP recommendation to bring the battery inside, at least in frigid climates. Your preference may vary.

I am not worried about hydrogen accumulation indoors. Normal ventilation does a pretty good job of taking care of any that may escape the sealed batteries (or even conventional lead/acid batteries). I have never had an issue, and have never shown any measureable flammable gas with a gas meter when I tested. Of course my house is 60 years old, and may not be as tight as some others. Gas accumulation in a garage is just as big a risk, BTW. Unless you store your vehicle outdoors, the risk is there. The only advantage to the garage is if you open and close the door regularly, itprovides more ventilation than your house door. Hydrogen could still accumulate and be set off, though, when you turned on a light after charging all night. The amount of risk is extremely small, however. Creating enough hydrogen to reach the lower explosive limit (LEL) may even be impossible due to the low lead and acid volume.

 

[MtlBen]

This forum is an endless, living source of information. Thank you all for the answers.

This topic has been discussed so extensively that I was sure my forum search missed something and I was expecting some answer that politely told me that if I did proper research, I would would have found the answer on the following thread...


...Ben...