The Syma S107 is a very popular micro RC helicopter that is especially great for beginners. One of the questions I am asked often is what flight time should you expect from an S107?
The answer is, it depends. I know, terrible answer. Unfortunately, the reality is that there is a lot of variability when it comes to flight times, or more specifically, battery life, which is obviously what dictates flight time. Battery life depends on factors such as the age of the battery, how the battery was charged, how many cycles it has gone through, and the load on the battery (which changes depending on how aggressively you fly your helicopter).
Syma Helicopter
Considering the variables above, I would say that a brand new fully charged S107 helicopter, hovered smoothly, could potentially stay airborne for about 5-7 minutes. If you're flying around a lot, it may be as low as 3-4 minutes. If the battery wasn't fully charged, if it was overcharged, or charged too quickly, flight times could be significantly less. It's also important to note that as time goes on, with more charging cycles and age, the battery capacity will reduce, leaving you with less and less flight time.
Eventually, the battery will become unusable. Generally speaking if you start to see flight times of less than a minute, it's probably time to start considering the battery toast. But don't throw out your helicopter yet. Replacing the battery in an S107 is a pretty simple process and certainly much cheaper than trashing a perfectly good helicopter. Just get yourself a replacement battery of either the same or larger size (why not do a little upgrade while you're at it). Once you have the battery, just remove the canopy, pull out the old battery, shove in the new, re-balance the heli, and throw the canopy back on.
It can be frustrating when your helicopter seems to be loosing its jam. Unfortunately, it is inevitable. The good news is that if you prepare for it and buy parts proactively you can avoid any downtime.