I posted this a while back;
Batteries 101
I work in the lighting industry and deal with small, deep cycle , lead acid batteries every day. I did a bit of research for y'all Grin
The basics;
There are several types of lead acid batteries. For our purposes , powering flashers etc, we'll most likely use sealed, lead acid type batteries of parallel plate construction.
How they work;
A battery cell consists of two lead plates a positive plate covered with a paste of lead dioxide and a negative made of sponge lead, with an insulating material in between. The plates are enclosed in a plastic battery case and then submersed in an electrolyte consisting of water and sulfuric acid. Each cell is capable of storing 2.1 volts.
In order for lead acid cell to produce a voltage, it must first receive a (forming) charge voltage of at least 2.1-volts/cell from a charger. Lead acid batteries do not generate voltage on their own; they only store a charge from another source. This is the reason lead acid batteries are called storage batteries, because they only store a charge. The size of the battery plates and amount of electrolyte determines the amount of charge lead acid batteries can store.
When a fully charged battery is connected to a load (flasher for example) the chemical reaction between sulfuric acid and the lead plates produces the electricity. This chemical reaction also begins to coat both positive and negative plates with a substance called lead sulfate also known as sulfation . This build-up of lead sulfate is normal during a discharge cycle. As the battery continues to discharge, lead sulfate coats more and more of the plates and battery voltage begins to decrease. The chemical reaction is slowed.
Lead sulfate is a soft material, which can be, and is, converted back into lead and sulfuric acid, provided the discharged battery is immediately connected to a battery charger. If a lead acid battery is not immediately recharged, the lead sulfate will begin to form hard crystals, which can not be reconverted by a battery converter/charger.
Can your battery freeze?
If your battery is partially discharged, the electrolyte in a lead acid battery may freeze. At a 40% state of charge, electrolyte will freeze if the temperature drops to approximately -16 degrees F. When a battery is fully charged the electrolyte will not freeze until the temperature drops to approximately -92 degrees F. If your battery freezes there is a high risk of internal damage to the plates. The battery case will most likely be damaged by the expanding electrolyte as it freezes.
Battery Maintenance;
Undercharging - Generally caused by not allowing the charger to restore the battery to full charge after use. Continuously operating a battery in a partial state of charge, or storing the battery in the discharged state results in the formation of lead sulfate (sulfation) on the plates. Sulfation reduces the performance of the battery and may cause premature battery failure.
Overcharging - Continuous-charging causes accelerated corrosion of the positive plates, excessive water consumption and in some cases, damaging temperatures within the battery. Lead acid batteries should be charged after each discharge of more the 50% of its rated capacity and during or after prolonged storage of 30 days or more.
Charging;
It's critical to use a "smart charger". Using a charger that produces a constant voltage will overcharge the battery causing excessive heat and deterioration to the plate structure. Smart chargers vary the voltage according to the state of the battery's charge and limit damage during charging.
Low temperature performance;
Batteries rely on a chemical reaction to discharge their stored energy. As with all chemical reactions, heat is the catalyst and cold the inhibitor. Standard parallel plate lead acid batteries do not produce the same voltage or capacity in cold temps as in warm temps.
By the way...I don't use electronics on the ice
RG
There is a new type of lead acid battery called a "Spiral Cell" that may take over the battery market if manufacturers can produce them cost effectively. Spiral Cells show no negligible change in discharge rate or voltage in cold temps.
