To anyone who did an internal di2 battery, what connector are you using?

I have a tenergy airsoft battery I am going to use with my build, but am a bit unsure whether I should stick with the mini tamiya connector or not. Is there a lot of concern with water entering the plug? I figure I can dab some silicone in the exposed areas and heatshrink the entire assembly after connected.

just cut the shimano connector off the battery mount and splice this onto the LiPo battery.... red to red... black to black... then connect as usual.... then u dont have to worry bout compatibility issues, or waterproofness....

How do I charge the battery without cutting and soldering every time then?

On the tenergy I used, there were 2 connectors, one generic, and one for charging...
Cut the generic off and solder/heat shrink the shimano connector on... The charging connector remains to allow easy charging....

Internal routing on a P3C using JST connectors on the power leads for me.

I don't have the original di2 battery, that's probably why I was confused

Looks like I'll just stick with the mini tamiya connector and shrink wrap the connection

Not the battery, just the battery mount... It is standard with the internal wiring harness.... Just cut the mount off the harness and join the battery on at this point, leaving the charging connector in place

Ah thanks a lot, makes sense. I was a bit confused because I don't have a balance charger, just a generic lipo battery charger (2 pin setup). Gonna see if I can exchange it for a 3 pin balance charger, this seems like the cleanest solution

Here's version two the battery. Now with 18mm carbon fibre tube & capped with resin/micro-balloon slurry. weight is down to 60g.

Just got the internal harness in today. Lucky I ordered the harness that has an extra long wire for the seatpost battery looks like it will fit perfectly.

Cut off the battery wire and I see there are two red two black. I'm assuming there are 2x positive/negative from the same power source, is that correct? If so it looks like all I have to do is solder the positive and negative to the battery 2 leads to one. Seems logical, just wanna be 100% sure!

Thanks for the help guys

Version 2 looks good Pete, when can I get my hands on one?

Yep