Something is not looking right in your original post. The connector is one color, which is correct, I have several of them.
I would really need more up close pictures of both to be sure.
The ESC HXT150 4MM Bullet female to XT90 male Connector Adapter should have worked. Of course, always make sure the polarity is correct.
You also have "AS150" connectors. In one of your post, you state: They are not new batteries. I got them as used and the original owner said that he used them about 50 times.
Did he possible solder them up wrong?
The banana plugs in the picture looks like XT150's in the first picture at the bottom. They are connected and solid red. Same with the picture to the right. Those are XT150's.
This plug should have worked (after checking the polarity):
Look at the "sub pictures" at the bottom of the big picture.
These are "AS150's.
Then you have the Supra's, which are great, but expensive. If I needed 100% secure locked connectors, I would use the Supra's. But the connectors are similiar.Here is a perfect picture of a HXT150 connector. Picture is self explanatory.
This video show a battery with XT150 connectors.
Watch at YouTube
Looking at the picture from Ebay, the picture with several 150 connections, it shows the wires reversed. look at the left picture, then look at the right picture. The wires are reversed. The connector should have worked, however, you should have verified the polarity. It is easy to get these connectors confused. Bottom line, I would have put another XT90 on so the connector would match. The XT90's have the polarity stamped on the side.
EC5's, EC3's, and XT60's are all great plugs.
If we can help, don't hesitate to post questions.