Lead Acid Batteries A beginners guide to Lead Acid batteries for use in EV's.
Lead Acid Batteries are the most tried and tested battery for EV applications, the low upfront cost and their resistance to abuse means they are the battery of choice for most EV conversions. For use in any EV the only lead acid battery that should be considered is a deep cycle. These come in several variety's:
Flooded wet cell: this is perhaps the most common battery type for use in most road going EV's. The most common brands being Trojan, US battery, although several others exist. These are typically used in marine, RV, golf cart, and forklift applications.Flooded wet cell batteries are composed of thick lead plates submerged in a sulfuric acid/distilled water mixture. they come in 6volt, 8v, and 12v, and, I believe, some industrial units are available in 24v
Flooded wet cell batteries typically have the highest AH (amp hour) rating, meaning they can go the furthest distance, but are somewhat limited at how fast they can release their energy. SInce they are specifically made for deep cycling applications they tend to have a long cycle life compared to other batteries that focus more on producing amps. This makes them better suited to commuting than competition.
AGM: The absorbed glass mat battery is exactly that. Several lead plates are stacked with a thin fiberglass mat between each layer. This mat is saturated in an acid mixture, that completes the reaction to create voltage.
AGM batteries are manufactured by OptimaOrbital/Exide and Trojan as well as others
The AGM is typically not of quite as high of an amp hour rating, as the flooded type, but has many advantages, that make it a very desirable battery as well.
The AGM is by it's design very resistant to vibration, and even if broken open cannot leak it's acid mixture because it is held within the fiberglass mat like a sponge, that is below it's saturation point, so it will not drip.
The AGM can be charged, and discharged at very high amps without damage to the battery. This makes the AGM well suited for competition use, as well as being suitable for commuter use.
The AGM is a truly maintenance free battery, requiring nothing but proper charging for the life of the battery.
I will add to, edit this entry as I can. feel free to edit mistakes or lacking information as you see fit
Recycling and Waste production of Lead Acid Batteries: Between 97-99% of the LA batteries are recycled with most of the remainder ending up in landfill and 1:120 000th of the battery ends up in the atmosphere or 0.0000083%. Lead is the most highly recycled non-precious metal. Out of a considerable twenty-four by 62lbs (Trojan t105s) battery pack at 1500lbs (680kg) around 15-45lbs (6.8-20.4kgs) would end up in landfill and 0.0125lbs (5.6 grams) would end up in the atmosphere. According to the Energy Information Administration the average American produces 4.5lbs (2kg) of garbage per day and with an EV that would increase by 0.027lbs, an 0.6% increase. That is replacing a 1500lbs (680kg) battery pack every 3 years at 98% recycling.
State of Charge to Voltage Chart for 12V batteries: This chart will help as a general guide for the state of charge of 12V batteries, though it not be accurate for your particular brand of battery so do not rely on this source alone.
Detailed Articles about Lead Acid batteries: http://www.vonwentzel.net/Battery/00...ary/index.html http://www.marine-electronics.net/te...q/b_faq.htm#12