I would be amazed if you damaged a Di2 so easily.
I have in a few crashes ended up with bruises at the shifters. I used Sugru and made a bumper on my RD which works great.
No problems what so ever with my Di2. I heard a few guys managed to crack exploro ltd frame.
I had a tire deflate in a few seconds in a turn from tarmac to gravel. Did a serious flip and smashed myself and the bike pretty hard.
Nothing got damaged except cosmetics (looks like i've been using a file) on the shifters.
It's a freaking tank, the Open UP.
Back to Di2, if anyone says Di2 or a carbon frame doesn't stand a beating, It's not my experience
Sure a frame can crack, but that's most likely a thin wall and/ or a frame with stiffer/ brittle carbon.
I have one of those to...
Needles to say, if my Ax had seen a fraction of what my UP been through, i've had the worlds most expensive puzzle.
Sure, batteries can drain, but that is another thing.
Shimanos new battery (shimano bt-dn110) is better than the sm-br2. I had two of these failing.
The new, no problems what so ever.
Only thing that cracked was a helmet and a jacket got torned up.
Oh, and me