How to keep a battery running in 12 degree F?

[cara2000]

Hi,

1. I have an electric Fence (premier brand) and for the last few days we had rain and below 20 F temperatures. The AGM battery (SLA1104, 12V 12 AH) is flashing read almost all times. What can I do to keep it charged? Would battery blankets be enough for 20 F? If yes, can you recommend one.

2. Should I switch to a LiFePO battery? I read they have the same issues with low temperature charging

Thanks!

 

[chrisski]

An AGM battery should be fine at 20f. Electric blanket will have no effect.

I suspect something is shorting your fence to the ground draining a battery. I saw someone touch a fence, felt nothing, then inspected it to find where the short was.

 

[cara2000]

An AGM battery should be fine at 20f. Electric blanket will have no effect.

I suspect something is shorting your fence to the ground draining a battery. I saw someone touch a fence, felt nothing, then inspected it to find where the short was.

Thanks! So, are the AGM better in cold weather than LiFePO4? Contemplating to buy a LiFePo4 as a replacement

 

[chrisski]

Lithium can’t charge below freezing, that’s a problem.

The battery spec sheet on the AGM should contain a chart that says what temp it will operate in based off the SOC, but yes for use where the battery is below freezing, AGM is better.

Lithium batteries can have heaters to overcome cold issues, but that adds cost.

 

[Zwy]

Thanks! So, are the AGM better in cold weather than LiFePO4? Contemplating to buy a LiFePo4 as a replacement

Lead acid whether flooded, AGM or gel would be the choice in below freezing temps. LFP will die soon if you charge below freezing, the anode gets coated with lithium according to research papers.

I'm assuming this is a solar charged fencer? In the winter time with the sun low on the horizon, the yield from solar may not be enough to recharge the battery. Most likely you had a few days with little or no sun and low solar yield. You have a few choices, more or bigger solar, swapping out batteries in low charging conditions or adding more battery capacity to make it thru such periods.

If the lead acid type battery is constantly run below 50% capacity, it will sulfate and suffer a much lower lifespan compounding the problem.