One guess. The frozen cell has shorted, and discharged over time. This would explain the sluggish performance (cell as resistor) and frozen electrolyte resulting from reduced acid fraction (low SG).
There is a good chance the battery case has cracked due to ice expansion, so be prepared for dilute acid leakage as the battery thaws. It can get cold around here (-42 with wind chill yesterday morning), so I have seen a few cracked battery cases.
It would be interesting to put a voltmeter on the battery, and see if it reads closer to 4 volts or 6 volts.
I'm curious. Is it a centre cell that froze, and is it a Trojan battery?We have had a few -30 nights in the past couple of weeks and my ET sleeps outside. On a couple of -20 days I have been plowing, the performance has been sluggish to start (power meter showing fairly high draw), but gets better after a few hundred metres of moving and plowing. I'm guessing the transmission fluid needs to warm up a bit before the E12 is happy.
Main snow bank is now about 5-6 feet high, so I'm pushing snow past it to a second pile now. Tractor charge is holding up though - I'm usually past wanting to quit before it starts petering out. I think this is year 9 on the bargain Exides (mismatched from multiple lots at season close-out). Pretty sure it's time to start looking for replacements - maybe 2 sets - as there is an E15 acquired in the fall sitting under a snow drift in the side yard I had hoped to get into the garage to check over this winter. However, snows came early, and that did not happen. (So many projects, so little time.)
Darryl On 18/02/2015 7:33 PM, RJ Kanary wrote:
Two possibilities. One, nothing, that cell is history, or Two an explosion.That battery is probably a write off. Bring it up to room temperature SLOWLY and attempt a recharge in a safe, preferably /outdoor/ location. I have witnessed lead-acid battery explosions in automobiles. It is a memorable experience. RJ On 2/18/2015 7:18 PM, Charlie wrote:When I was plowing yesterday, the I-5 was sluggish at first, and never really got up to the usual level of power. I also noticed a strange sulfuric eggy smell at times. When I put the charger on, it was unusually loud. So I checked all the batteries and I found that one of them had a single cell frozen solid! The other two were fine, as were the other five batteries. I was trying to be careful about not letting the batteries get discharged, to prevent them from freezing. In the fall I carefully checked every cell with a good quality temperature-compensated hydrometer and they all looked good. The charger and electronics are the simpler late model type, the tractor's a 1973 I-5. Does anybody know what happened here? Is the battery irreparably damaged? What happens when I charge the pack with one cell frozen? --Charlie
-- Darryl McMahon Freelance Project Manager