I can't seem to find the links on this computer. They must be on my other one. Here is a tid bit I found in a doc I saved.
Charging methods for RC Lithium Polymer Packs
1.
Traditional: A charger will charge an entire RC Lithium Polymer Pack either 2 cells, 3 cells, or 4 cells pack. Because cells in each pack are series connected together, an electric current will flow from one Polymer cell to the next. The cells in each pack will receive the same amount of current.
There is a potential problem for this charging method. Because cells may have different internal resistance or slightly different capacities, each cell may require different amount of charging. However, if cells are getting equal amount of charge, some cells will be under-charged and some cells be over-charged. For over-charging a cell, the cell will get damaged and its internal resistance will increase and capacity decrease. This cell will then be susceptible to further more serious over-charged when charge again in series with another healthy cell. This creates a vicious cycle to damage one cell in a 2, 3 or 4 cell pack. When a single cell gets damaged to a certain condition, the entire Lithium Polymer pack will need to be replaced.
2. Safety Charging: (A battery pack needs to have special wiring)
A charger will monitor each cell in a Lithium Polymer Packs. Each cell is individually monitored so that no cell will be affected by other cell physical or chemical conditions. When one cell in a pack reaches the maximum voltage (4.25V), the charging will be stopped and no cell will be overcharged. This is to ensure that all cells in a lithium polymer pack will stay at a healthy condition after hundreds of charging cycle!
In order for safety charging, a Lithium Polymer battery pack needs to be specially wired. Each battery pack will have two wires coming out of a pack. One is for discharging and one is for charging purposes. The discharging wire series connects all lithium polymer cells and charging wire parallel connects lithium polymer batteries. This is the next generation advanced charging method. This advanced charging has been employed in electric cars where battery packs are expensive.
Furthermore, one can use the discharging (series connected) wire to do all charging and discharging. This lithium polymer pack will then behave just like a traditional lithium polymer pack. For advanced lithium polymer charger where individual charging is available, it also can do a traditional charging!
Here is way to much info that no one can understand
http://www.eetasia.com/ARTICLES/2004DEC/A/2004DEC15_POW_AN.PDF
