Hey folks, newcomer here, but have been having fun flying my Phantom 2 for many months.

Recently, I had a crash.  I think it was due to a battery problem.   Battery showed at full
charge (4 lights) before take off.   I took off, and was hovering at a bout 5 feet for about
1 minute, while deciding on my flight route.  Then the lights changed from flashing green to
flashing red.  I could no longer control the Phantom.   Within a few seconds, the props stopped, and
the Phantom simply crashed straight down.  Luckily no permanent damage.  Gimbal was bent, but that was
fixable.   I do not believe I completely lost power, as the Gimbal was still running, and the unit was humming.
But the props were stopped.  When I checked the battery, it was now down to only
2 lights !  (Yes, it went from 4 to 2, in a matter of about 2 minutes).  

So, I tentatively concluded something was wrong with the battery.

Bent the gimbal back into shape, and tried another battery.   Full normal flight.

So, some questions :
- has anyone else experienced anything like this ?
- how does one check for battery health ?  is there good way to do this, to prevent
such crashes (I was lucky I was only 5' above the ground when this occurred - if I
was higher, and/or a distance away, this could have easily caused permanent damage
or worse, hurt someone)
- what is the best strategy for ongoing battery maintenence

Thanks in advance,

Batteries are the beast of the airways. You can never predict a problem. However you can try to keep check on them. When they do act up you need to check them throughly and replace if needed. A lot of hype about batteries but the keys are. Do let battery sit for days on end at full charge. Store at around 50% level. Never run it down below 20% for normal flying. Once every 20 cycles  run it down to 8% the fully charge it back up. This help to level out the cells and extend battery life. If a battery does act up. Put it in the quad and connect to the assistant. Look at the battery info and see what it shows. Look at each cell and see if they are fairly close together under cell voltage the mV of each. Check also if any errors are showing up. If all looks good the the only thing you can do is fully charge the battery then checking the assistant again.  If all still looks good then test fly the battery alt very low altitude and close by over a soft grassy area. Watch the OSD battery level and if it rapidly drops at any time from a round 65 percent down to 20  or anything like that land and shut down. Pull the battery and press and hold the start buton until it flashes see how many led's are lit. Probable less than 4 so time to replace this battery. It's not reliable. If your test flight went ok and the battery held I would recharge and test one more time before hoping air born. You have to be sure that battery is reliable. Only way I know is to test, and retest from a safe height.

roy@mcscomputer Posted at 2015-8-6 21:17
Batteries are the beast of the airways. You can never predict a problem. However you can try to keep ...

Thanks for that.