ORIGINAL: propnuter
Every battery has some disadvantage. In the case of the A123’s not being able to check the battery before flying is an inconvenience. However I think it just requires a change of mind set and more disciplined charge monitoring.
This is easy, just plug it back into the FMA charger and read the "fuel gauge". This only takes about 5-8 seconds and gives a somewhat-accurate depiction of the remaining charge.