Just did some hacking into the smart battery and was very surprised by the stupidity I found in there... I'm about to get into my own extended battery build and need to chop out the "smart board" from this stupid battery... Did some tracing and figured out how I'm gonna use the board etc... (will post more on that later) Then as I was sitting there daydreaming how I would go about this ... and at the same time reading the forum ... I noticed something so completely irresponsible i can't even believe I'm putting my $1400 up in the air with this piece of **** :twisted: Look at it for a second... And I've labelled it so it's glaring at you... Top board is "smart board"... Lower board is just a consolidator putting all the cells in parrallel and series... Marked that lower board with double arrows showing current path... Do you see it?!?! THIS IS A SIX CELL BATTERY RUNNING IN THREE PARRALLEL PAIRS WITH THREE BALANCE LEADS... COMPLETELY UNACCEPTABLE!!! AND... HERE'S WHY... You can't accurately balance two cells in parrallel with a single balance lead... look at any of the major branded , reputable battery manufacturers and you won't see it done this way... When the battery is at rest it's not a huge problem because if the cells differ in value they will balance eachother off... the problem occurs during charge and discharge... the scenario: let's look at cell one as two parts ... cell 1a and 1b ... (I'm about to exaggerate numbers to show average and make a point) cell 1a is running fine... very healthy cell 1b has a problem... lithium contamination you launch your bird... cell 1a is outputting 12.4 volts at startup as normal cell 1b drops to 10 volts immediately because of the defect and is quickly draining your smart board is seeng the cell 1 voltage as 11.2... (the average of the good and bad cell both soldered to the same balance lead) Under these conditions you will notice something is wrong because you will get an early low battery warning and land or whatever... But let's say the numbers are not so exagerrated and cell 1b wasn't that bad... just "out of balance" Now your bird will fly too long and undervolt that cell and damage it... Then you will go back and put it on the charger thinking it's all good... and it will still have a low volt problem... causing cell 1a to high volt and damage during that next charge cycle... (it's trying to hit 12.4 as an average between the good and bad cell) Now you have this landmine of a battery that has destroyed itself in the span of one flight and one charge and won't fly past 50% of it's rated time on the app... and you're out 2000ft away ... and can't make it home ... and have to go and chop down a goddamned tree to get your phantom back!!! SOUND FAMILIAR ANYBODY? I'm just ranting I guess... lipos get old and fail and have problems like anything else... but usually the slowly fade away and you see it coming over several flights with decreasing flight times... But don't sell me something and call it "smart" when it has this kind of stupidity built in... jeeezzzz that gets on my last nerve... as the other guys thread said... "No more using DJI batteries for me" I also had an early low battery warning last week and after reading DirtyBird's post... I'm glad I didn't go out and fly with it again... I don't own a chainsaw :?