These are factory fitted to connect a 6S battery (up to 12,000 mAh) to the aircraft. Rather than hack them off I would prefer to make up adapters.
They look like double 3.5 mm banana plugs and sockets but do they have an official name I can use to find a supplier?
Bullet connectors - the best option ever. All my best aircraft use them!
They look like there is no polarity bias, can they be inserted either way around?
Buĺets, yes, but I’ve not seen them doubled as one unit like this before. i have 6S batterries with xt90, xt60, ec3 and as150 plus a weird mikrocopter connector but nothing like this 
The pointy bit is negative, the socket positive. Each is attached to a single wire. I assume that the connectors are doubled but cast as one unit to handle the current. - each of the four motors draws a maximum of 25 amps from a 6S battery,
Still searching for these little chaps but I have a strong feeling I may be replacing them with something mainstream.
In my search I came across this very useful guide to connectors, capacities and how to solder them:
Interesting article,
I once used the bullet connectors between 30amp ESC’s and motors but every now and then one of the motors would puff out!
This would only happen under full current draw or close too,
after some deliberation I came to the conclusion it was the Bullet connections was causing the voltage drop. I did away with them and soldered directly and never had the same problem again.
Because spring bullets have a sleeve that wraps around the main body of the pin, there actually is not that much contact area in relation to the length of the pin. Only the small top and bottom area of the sleeve are in direct contact with the inner pin.
Found These
These are the connectors in situ
They are screwed to a slide out battery tray. The idea being that you strap the battery to the tray, connectup and slide in. Contact is made with the fixed pins on the aircraft and the fixed socket on the battery tray. So it would be possible to have additional trays preloaded with large capacity 6S batteries that just slide in. The rear door locks the tray in place and has an on=off button and a 4 LED power display similar to DJI Mavics and Inspires.
Thanks for the suggestion Wayne but the killer with these deals from the States is the hideously overblown postage cost. In this instance eight quid for the connectors and fourteen for the post - on a pack that will weigh less than 100 grams even with all the customs labels pasted on.
I’ve also found the average American is appalled when I suggest that the package be labelled as a gift. If even a penny of customs duty needs paying the parcel carrier acts as the agent for HMRC and collects the duty - plus an eight quid fee for doing so.
I’m away to check which of my batteries fit the long but slim battery cutout and will modify connectors to suit
Sorry Rob I didn’t see they are from California 
Found these though
Now it gets interesting!
Just had a rummage and found I only have one type of battery that fits. The 16,12 and 10 amp/hour are all too large for the battery compartment so it’s going to be a 6200 mAh 35C with XT90. The battery plate allows two to be mounted so that will give me 12 amp/hour for about 30 minutes of flight.
Out with the soldering iron!
