The ones you pictured are Known as superseal connectors and a pita to use to be honest.
Cant remember if you also need a removal tool to get the connectors out.
Years ago, when caravanning off grid, I used to work with two batteries for the caravan - one in the boot of the car on charge, the other in use in the caravan. In the boot, I had a cheap, mains, three pin 5a in-line flex plug socket. on the battery I had a plug, with crock clips. Providing I got the crock clips on the the correct battery terminals, as the 3 pin mains plugs were polarised, to wrong connections were possible.
Find many great new & used options and get the best deals for 10pcs 2 Pin Way Plug Car Waterproof Electrical Connector Wire Cable Automotive at the best online prices at eBay! Free delivery for many products.
Find many great new & used options and get the best deals for 6.3mm Pin Way Electrical Multi Connector Plug Motorcycle Scooter Car Kits at the best online prices at eBay! Free delivery for many products.
www.ebay.co.uk
Links in this post may contain affiliate links for which DIYnot may be compensated.