When to pull the battery?

[sinnettc]

We had a bit of cold weather this week which got me to thinking. . .

The Willamette Valley here in Oregon has fairly moderate temperatures but in the winter we do sometimes drop below freezing for several days. This week it was a couple of days with lows in the low 20's and highs near freezing.

Our battery is a 105 aH group 27(?) that's about 4 years old. The battery handled this first freeze fine, but the long-range forecast is for a colder than normal winter.

Verboten is on the trailer for the winter, with the battery in its spot in the v-berth and the solar panel hooked up to keep it charged. I don't have access to power so running a light or small heater is out of the question.

So, when should I start worrying about having the battery freeze?

 

[catsailor]

We had a bit of cold weather this week which got me to thinking. . .

The Willamette Valley here in Oregon has fairly moderate temperatures but in the winter we do sometimes drop below freezing for several days. This week it was a couple of days with lows in the low 20's and highs near freezing.

Our battery is a 105 aH group 27(?) that's about 4 years old. The battery handled this first freeze fine, but the long-range forecast is for a colder than normal winter.

Verboten is on the trailer for the winter, with the battery in its spot in the v-berth and the solar panel hooked up to keep it charged. I don't have access to power so running a light or small heater is out of the question.

So, when should I start worrying about having the battery freeze?

If it is charged it will not freeze, ever. No worries.

 

[Maine Sail]

If it is charged it will not freeze, ever. No worries.

Ditto, just keep it topped up to full charge or close to it and you'll be fine. The self discharge rates of lead acid batteries are also much slower in colder temps so it will stay charged longer and self discharge less on the cold boat than in your 65 degree basement...

Only a dead battery can freeze so be sure it is physically disconnected from the boat so no phantom loads can drain it off. Just pull the neg wire off and you'll be fine.

 

[sinnettc]

... self discharge less on the cold boat than in your 65 degree basement...

Basement? What's that?

Haven't lived in a house with a basement since I moved out here from Bass Harbor, Maine, in '77. My choices are in the house, in the unheated shed, or in the boat. I'll keep it in the boat I guess.

 

[sinnettc]

If it is charged it will not freeze, ever. No worries.

Thanks!

 

[Maine Sail]

Basement? What's that?

Haven't lived in a house with a basement since I moved out here from Bass Harbor, Maine, in '77. My choices are in the house, in the unheated shed, or in the boat. I'll keep it in the boat I guess.

Ahhhh.. The joys of homes with basements... Don't risk disc surgery by moving them. They'll be fine...

 

[PaulK]

When I went to school in Maine, people used to talk about bringing their car batteries inside at night so that they'd be able to start their cars in the morning. A warmer battery will still operate better than a cold one, even fully charged. Of course, they started doing this when it got to about 20º below zero in the daytime, and colder at night...

 

[Maine Sail]

When I went to school in Maine, people used to talk about bringing their car batteries inside at night so that they'd be able to start their cars in the morning. A warmer battery will still operate better than a cold one, even fully charged. Of course, they started doing this when it got to about 20º below zero in the daytime, and colder at night...

As the temps go down so do available cranking amps but you're not starting your motor in the middle of the winter like you do with a car. The cold temps will actually help it retain more charge while just sitting there. Warmer temps increase self discharge rates.

Our batteries are rated at 650 CCA (0F) / 875 MCA (32F) and at about 70 degrees they are over 1000 cranking amps..