Both Leo and I have the same kind of charger with: time expired, voltage, and amperage digital readouts. MrMulligan makes the same point about getting a charger with digital readouts. But they don't show you how the individual cells within a pack are performing. For instance with a new pack you should condition cycle it at least once before flying at a lower discharge rate somewhere between 2C-to-4C. With a battery monitor you can then check the voltage of each cell with the pack fully charged as well as the bounce back voltage 10 minutes, 30 minutes and 1 hour after LVC. That is really the only way you know for sure how equally matched are the cells in a new pack. That gives you the best picture possible of your LiPo's condition/quality and how often you need to balance a pack.
No matter what kind of a charger and balancer you get or whether you charge via the discharger connector or the balancer connector get a battery monitor. It will result in you taking better care of your LiPos and prolonging their life. Here are some battery monitor links.
http://www.headsuprc.com/servlet/the...ter-for/Detail
http://www.bphobbies.com/view.asp?id...7&pid=B2632602
http://www.all-battery.com/index.asp...OD&ProdID=1973
My A+,B,C- is my own arbitrary method based on expected flying time as compared with each cell's bounce back voltage after 10 minutes and 1 hour from the LVC. If you can only wait 30 minutes before recharging then check it at 10 min. & 30 min. For example if my flying pattern of a particular plane and a 1000mAh battery is 10 minutes when new, but becomes shorter over its life and the bounce back voltages become more imbalanced I think of its performance as:
10 minutes flying time = 100% = A
8.5 minutes flying time = 85% = B
7.0 minutes flying time = 70% = C
5.5 minutes flying time = 55% = D
( if I find out I bought an under rated 1000mAh that is more like 1100mAh then I'd rate it as A+ )
You do what works best for your own flying intersts and budget, but I would highly recommend you purchase a battery monitor. Then as you get more batteries and your not always sure of the charged or discharged condition you can easily check them out whether at home or at the field. Their individual cell condition also determines what rate you may want to charge them (1C, 0.8C, 0.6C).