Battery in Michigan winter ?

Lwiddis wrote:
“Trust me taking them out and bringing them inside your house is the way to go”

Why, Rock, if you can keep them charged? 85 percent charged freezes at minus 67 degrees F. See http://www.trojanbattery.com/pdf/WP_DeepCycleBatteryStorage_0512.pdf TRUST ME!

When I winterized, I started the MH every week and if no snow tried to drive it at least every two weeks. Not hooked up to any shower power. And I took the coach battery out.

I never used a trickle charger on it because previously on 2 occasions the trickle charger overheated the cords. IMHO after that for safety reasons I refuse to use them anymore......sadly they are all made in china and cheaply made now not at all like the ones back in the day.

A battery company asked me to help a distributor titrate a hot shot specific gravity for new batteries headed for Prudhoe Bay AK. To prevent the batteries from freezing when at 50% state of charge. It takes some fierce kind of cold to freeze a battery. Colder than anything in the lower 49.

Preventing any type of unintentional discharge is the key. A battery with a dead cell can freeze that cell. Sort of like machine gunning a corpse.

I live in Northern Minnesota. The trailer batteries and the two pontoon boat batteries all get fully charged and disconnected for the winter and left where they are. They are outside from the first of October until April without any problems. Been doing this for many years and have never had one freeze. cdru

MEXICOWANDERER wrote:
Definition of "Disconnected" either battery terminal with zero wires connected to it.

Yes and the case needs to be clean. The sludge on top is often plenty to run it down in storage.

Keeping the battery in the rig or six inches off a cold floor is not considered extreme high-tech.

Would be interesting to actually do a temp test of a battery case gradient. If temp between slab and air was 20°F difference, I wonder what the gradient of the case would actually be. Of course, if you actually put a charger on there occasionally, that stirs up the electrolyte and there wouldn't be an issue.

2oldman, now that was a classic answer.LMBO B stands for butt which sounds more cooth. :B

This was a finding, not an accident.

750 ml measuring column. Pyrex. 300 mm tall



Fill with new electrolyte. Titrate to 1.280 SG adjusted to 20c.

Place on concrete slab. Temp 10F - 30F
Air temp at center of column 50F - 75F

Temperature quickly fell as thermocouple temp was lowered center of column to floor but was never less than 12 to 15 degrees warmer than the concrete. There was no fan air movement present.

Sample reposed for (Cannot remember exact time but around three months).

However I do remember the final gravity as being 1.205 top 20 mm.

Opinion. Even though it sat in a relative temperature gradient the effect was clearly defined. The test was conducted off-site in an unused garage

A few years later, I measured the same column (stoppered) for a year at 40-90F and found an inconsequential amount of gradient differential.

Apparent is the evidence that Delta T between concrete pad and air temperature is key. Not the temperature itself.

MEXICOWANDERER wrote:

A floor that is + 40F and air that is 70F encourages stratification of electrolyte.

That's interesting...have any links that talk about that?

Sounds like keeping them on a charger and doing equalizing charges nullifies that correct?

Nothing like actually testing theory: :)

A floor that is + 40F and air that is 70F encourages stratification of electrolyte. This is anything but a black and white issue. The stratification is much amplified when tall batteries are involved. But place a car jar battery in such an environment for four months and stratification will be enough to "matter". The cure is absurdly easy so this shouldn't even be an issue.

Battery type and age enters into the self-discharge picture. High antimony batteries will self discharge about 150% the rate of car jar batteries. Calcium calcium starting batteries will discharge at less than 1% per month at -20F

Old batteries near death can discharge 20%+ per month. This is due to the nemesis of negative plate antimonial contamination.

There is nothing wrong with using a maintenance charging source. However if a lot of money, time and hassle is involved just to maintain batteries for a few cold months then common sense dictates the issue should be analyzed. A decision can be skewed by the additional need to maintain batteries in warmer weather due to infrequent use.