Batterys too cold to charge???

Chris Bryant wrote:
So it is fine to charge a battery that is frozen?

Chris ....

Your comment gives rise to a thought sequence with a possible interesting conclusion:

1. Does ice and/or frozen electrolyte conduct electricity?

2. If so, does a charging voltage applied to a frozen battery still result in some current flow between positive and negative areas inside the battery?

3. If so, will this current flow - even though small at first - slowly begin to unthraw the frozen liquid due to warming from the current flow?

4. If so, will this current flow gradually increase and consequently the warming increase?

5. Hence, is it possible to eventually unthraw a frozen battery by trying long enough to charge it (assuming it didn't freeze so bad as to burst it's case from expansion of frozen liquid)?

Or is there a good chance of explosion?

pnichols wrote:

Chris Bryant wrote:
So it is fine to charge a battery that is frozen?

Chris ....

Your comment gives rise to a thought sequence with a possible interesting conclusion:

1. Does ice and/or frozen electrolyte conduct electricity?
You can find out by putting a body part on ice and connecting a circuit across it. Prepare to be shocked.

2. If so, does a charging voltage applied to a frozen battery still result in some current flow between positive and negative areas inside the battery?
yes

3. If so, will this current flow - even though small at first - slowly begin to unthraw the frozen liquid due to warming from the current flow?
No, usually there is intense heat in one or more cells, aggravated by connector breakage from the freezing.

4. If so, will this current flow gradually increase and consequently the warming increase?See answer to #3

5. Hence, is it possible to eventually unthraw a frozen battery by trying long enough to charge it (assuming it didn't freeze so bad as to burst it's case from expansion of frozen liquid)?

[COLOR=]You may be able to "unthaw" the electrolyte by applying small amount of current at intervals but the end result will probably be an inoperable battery

When a battery totally freezes, there is expansion within the total case area and also withing the cell spaces. This tends to push plates and separators around and also causes connections to break. This is why it is unwise to try charging a frozen battery, it usually results in electrolyte expulsion and/or case failure.

smkettner wrote:
Or is there a good chance of explosion?

Quote:
Sensor/charger functioned just like they were designed.
---------------------------------------------------------
It sounds like you are defending the charger's operation.
If the charger had even a little bit of "smart", wouldn't it know that a battery w/ a voltage feedback of 12.4 in ambient temp, would not be too cold to charge, let alone not frozen ?

smkettner wrote:
Or is there a good chance of explosion?

Quote:
Sensor/charger functioned just like they were designed.
---------------------------------------------------------
It sounds like you are defending the charger's operation.
If the charger had even a little bit of "smart", wouldn't it know that a battery w/ a voltage feedback of 12.4 in ambient temp, would not be too cold to charge, let alone not frozen ?

Does not claim to be 'smart' just a bit of protection.
Example: The charger does not know if it was 50° below for two weeks and has just now warmed to 20°.

Why all the concern? No one is saying to replace anything. Your PD is fine for you. The OP just wanted some feedback on the best practice to restart the charging process.

Is nothing semi-automatic worth having?

When charging STOPS it does not mean "Semi" Stopped.

When a converter stamps it's little feet and screams "I say the battery is charged, so Screw you!" It doesn't mean reverting to full manual control of the process. But FEW of these gizmos are available with optional control TO GET IT RIGHT.

This is as insane as permitting THE GOVERNMENT full control to think for you

If you re read, he was questioning the smartness of the charger.
I am just answering his question,....No, the charger did not outsmart him at all. The charger is IMO perdy stupid to think that a battery w/ voltage feedback of 12.4 is frozen.

smkettner wrote:
Does not claim to be 'smart' just a bit of protection.
Example: The charger does not know if it was 50° below for two weeks and has just now warmed to 20°.

Why all the concern? No one is saying to replace anything. Your PD is fine for you. The OP just wanted some feedback on the best practice to restart the charging process.

Is nothing semi-automatic worth having?

FWIW, I just set up a Xantrex Freedom SW 3012 and the parameters I set are Battery bank capacity, 2 or 3 stage charging, bulk voltage, absorb voltage, absorb time, float voltage, and temperature compensation, along with alarm settings, etc. Sounds reasonably smart to me.

Another point is that I have seen completely dead batteries test at 12.5 volts- batteries that would power a very high impedance input to a meter, but not a #57 clearance bulb. I have not ever worked on a frozen battery, but I would much rather the charger default to the non-explosive mode is there is any doubt.
That's just me though.

Update:
Thanks to everyone for your responses.
I fell on the ice and broke my ankle just before this charging issue started and have been unable to try any of the ideas you have suggested,
Today the snow melted enough that I could make it out to the trailer. I unplugged the AC power, Turned the prosign 2000 2.0 off and back on and plugged the Ac power back on.
All is well. Charging at 14.9 volts and 30 amps. Outside temp is 32 degrees. Wish I could have tried a few things when it was colder to learn how to keep things going. Oh well next time.
Thanks for all your responses.