10 Pairs XT30 Connector Male Female Amass XT30U Plug Black with Heat Shrink for RC Battery

https://www.amazon.com/dp/B07NWD5NTN Those are the connectors I used for the battery leads. https://www.amazon.com/dp/B07CTRH86M Those are the XT30's I use. They fit nice and snug. I have the XT60's but that's somewhere deep in my previous order list. A cheap soldering iron and some decent lead solder and don't forget the "helping hands" and you're set. I suggest heat shrink tube for covering the solder, just safer in the long run. Now I can charge those batteries with the d300 and look at the cells directly. If I remember correctly, when I first hooked it up I was at like 3.2v and 3.4v on the cells or something wild. My last storage charge they were both identical sitting at 3.789v according to the D300. Luckily the charge port is wired correctly for a balance lead, so you shouldn't have to make an adapter for it like you would a Traxxas battery. Hope it helps my friend. Those USB chargers are nice for "on the go". But they just aren't very dependable.