Trickle charge freezing battery

I'm worried about my battery .
Where the bike sits , the night temperature goes a couple of degrees below
freezing .
Will it be OK if I leave the bike's battery connected all night to a
'trickle-charger' such as the Oxford Oximiser .
It is recommended to leave the Oximiser connected when the bike is stored
away for long periods .

Will the trickle charger save the battery from going down with the cold ?


Thanks
Chris

 

It gets down to freezing where I live at night during the winter, so I
hook up a 3 amp trickle charger to boost my battery about four hours
before I need to start the engine. The starter spins merrily and the
engine fires right up instead of grinding the starter slowly.

It would be best if you could remove the battery and store it in a warm
dry place. That would be worthwhile if you're not going to start the
engine for weeks at a time.

The cold outdoor temperatures will decrease the specific gravity of the
electrolyte, reducing the battery's cranking and load carrying
capacity. Unsupervised trickle charging over a long period will
dehydrate the battery.

But the trickle charger will keep sending energy to the battery, and
that electrical energy will turn into heat.

If the battery would take a continuous 2 amps of trickle charge
current, that's
2 X 15 = 30 watts.

A 30 watt heater would definitely keep your battery warmer than if you
weren't charging it at all.

But, if the battery is sufficiently charged to only take about 1/2 an
amp, you'd only be getting 0.5 X 15 volts = 7.5 watts.

So the amount of heat a trickle charger would put into the battery
varies according to the battery's state of charge.

Since you appear to be able to run an electric cord from some outlet
over to the motorbike, it seems to me like you could plug some kind of
an electric heater into that same outlet.

I was reading about a guy who owned a rare sportscar with a
manually-controlled
planetary gear transmission. It was like a retarded automatic
transmission, it didn't know when to shift gears.

And the transmission wouldn't work right if he didn't heat it up before
driving. So he kept an electric heater underneath the transmission and
warmed the transmission up before driving the car.

Of course, there's a fire hazard with untended elecric heaters. But
most people who live in the cold parts of the world do manage to use
engine block heaters without burning their garages down.

 

Should be fine.

Depends on what you mean "going down." All chemical batteries will lose
energy when it gets colder, no matter what you do. Even the maximum
capacity of the battery goes down, so adding a trickle charger simply
makes sure that the (now temporarily smaller) battery is fully charged.
Of course, this situations reverses itself when it warms back up, so no
trouble.

If you mean "prevent my battery from being flat in the spring" then, yes
it will. Of course, temperature has little to do with self-discharge
over time other than affecting the rate at which it happens.

--
Later,
John



'indiana' is a 'nolnn' and 'hoosier' is a 'solkk'. Indiana doesn't solkk.

 

As I read an earlier answer, I thought there was a need to clarify
a few points.

It's not clear from your post if you use the bike daily or if it is
in winter hibernation.
Anyway, it is a good idea to use your kind of "intelligent" charger
during storage, hot or cold. It keeps the battery fully charged and
a charged battery will not be destroyed by sulphating and will not
freeze (except in extreme arctic conditions). If your bike is used but
does not keep the battery fully charged because of some electric
system fault, keep the charger on during the nights (until the fault
has been corrected).

For long term storage it is best to keep a battery cold and essential
to keep it fully charged.

An "intelligent" charger will not overcharge the battery, cause
much heating or "boil off" the electrolyte. AFAIK, the Oximiser
is in this category, some others are the CTEKs and Optimates.

A 2 or 3 ampere charger is definitely NOT a trickle charger when
used on a normal size MC battery. FFS, on many small batteries
3 amperes is the recommended "real" charging current!
That said, there could be some merit in heating up the battery by
doing a short (hour? half hour?) full current charging before
starting. You need a small "dumb" car charger to do this. And
keep an eye on your electrolyte level. But, with the bike and
battery in good shape and a reasonably easy cranking engine
oil (5W-40 synth rather than 20W-40 dino juice for example)
it shouldn't be needed.

"Dumb" trickle chargers exist but are not really a good option
except if one can't afford to get something better. A MC
trickle charger will probably be something like 0.2 to 0.5
amperes.

 

For well pumps, they advise that just a standard
incandescent light will throw off enough heat to work
nicely in a small enclosure.

 

At a 50% state of charge, electrolyte in a lead acid battery will freeze
if the temperature drops to approximately minus 20 degrees F. When a
battery is fully charged the electrolyte will not freeze until the
temperature drops to approximately minus 90 degrees F. Keeping a trickle
charger on your battery will not keep it from freezing if the
temperature drops below minus 90 degrees F. Does it get below minus 90 F
where you have you bike stored?