Hello! I recently became the owner of a DJI Phantom 2, just starting to get to grips with it :-)

Personally I find the software and documentation not particularly intuitive to use - the first thing I wanted to do was understand and use the 'Failsafe' feature for automatic RTH via switch S1 (something I thought would have been configured by default 'out of the box' - not so, it appears). I had downloaded and installed the RC Assistant and the Phantom assistant, and it took a while to realise that the RC Assistant doesn't cover this feature, and that you have to use the Phantom Assistant to configure switch S1 (with the other two positions 'consultable' but not 'configurable'). I had initially only used the Assistant to configure the Phantom itself. Also, from what I can gather, it's best to have both the RC & Phantom hooked up to the PC via USB when configuring via the Assistant, since some tabs are for the former and some for the latter (& some parameters are written to both devices)? In conclusion I would've appreciated a section for dummies like myself 'How to set Failsafe/RTH' which explained the procedure step-by-step (but perhaps I wasn't looking in the right places) :-(

Anyway, I have a short question regarding the low battery/RTH feature. I did a quick search on the web, but didn't find a direct response to the question, although I imagine that I'm not the first person to ask it by any means, so my apologies for no doubt repeating an oft-posed question.
Basically I assumed (wrongly, it would appear) that when the Phantom reached low battery level, then critical low battery, at some point it would automatically land or return to home, depending on how it's configured (a check box in the Assistant software for the latter if I understand correctly). So yesterday I kept my Phantom flying, through the red flashing Low battery warning, and then the faster flashing 'Critically low' warning, expecting the Phantom to land of its own accord at some point (like I said, I'm a newbie). I did however take the precaution of flying it only a couple of feet above the ground at this stage. So the battery finally emptied completely and the Phantom dropped dead to the ground (with a disturbing bump - thankfully it was on pretty soft grassy ground). So the lesson I learned from this is that as long as you don't relinquish control on the remote during the low battery phases it'll keep flying (albeit a bit less energetically), thus overrding any auto-land/RTH procedure, it's only when you release the sticks that it'll land or RTH automatically?

Welcome Duncan! I am no expert either, but have been there, done that so will try to share what I have figured out!  I will go down your post line by line with my comments....

Actually, out of the box, the right switch IS configured for RTH!  Your phantom new comes as 'phantom' mode, not Nazi mode.  YOU change that if you want (and should) via assitant software.  top right of first page.  Changing it DOES drop RTH programming on bottom of switch and it needs to be reprogrammed.

You said "it's best to have both the RC & Phantom hooked up to the PC via USB when configuring via the Assistant"  not so.  your assistant software, hooked via phantom itself, talks to rc controller by itself - no additional wire needed.

as for RTH, that happens if you click the box in assistant on battery page telling it to come home if low battery.  there is no % given;  it is an algorithm inside the phantom that best guesses exactly when it needs to begin RTH based on stuff I dont know (distance from home? speed? etc).  anyway, from reading posts for almost a year, it seems this is around 15-30% somewhere.  

Next, if you go past this auto RTH level, or don't have it picked in the assistant, then you keep flying until low battery is reported, as which time it will automatically land WHERE IT IS.

If you somehow go past THIS safety, then at 8% the battery says sianara and shuts off.  Seems you ignored both safeties and let it shut off.

I fly from 100% down to 60% typically.  Sometimes to 50%, but I totally stay above 50% to not have to worry about these problems.  The 8-10minutes flight time I get this way has so far been sufficient for me.

Welcome to the forum and keep reading/learning/asking-questions.

Hello, thanks for the prompt response

Regarding the USB connection, I hadn't thought of that - when I was hooking things up to the PC for configuration, when the RC wasn't connected via USB it was powered off, I guess I should have twigged that the RC and Phantom can communicate wirelessly - duh! So the next time I'll just connect the Phantom via USB and switch the RC ON.

What I don't understand is the 'when you ignore this safety' bit - I imagined that you COULDN'T ignore it, that the Phantom would 'wrestle control' from me at some point and land regardless of what I was doing with the RC, but from my experience this never happens - if you keep using the RC to control the Phantom (and I guess if you're not being very smart, even when it's not near enough for you to see the flashing red low battery indications), apart from sluggish ascent response you can fly until the Phantom simply drops out of the sky, battery flat. Admittedly you'd have to be pretty pig-headed and daft to create such a situation, but I really thought that at some stage the Phantom would take control and land itself. So I was curious if this was indeed the intended behaviour or if I was missing some fine point in its configuration? All part of the learning curve I guess!

P.S. If anyone else out there has similar experiences I'd be interested to hear about them - I'd really like to know if I'm missing a configuration parameter somewhere, or if normal operation is that use of the RC overrides any auto 'low battery' mechanisms and you have to 'relinquish control' for them to kick in!