https://images.app.goo.gl/nnitBXLGUy3ewKGQ6
Like that?
I just use a normal balance lead inserted into the right part of the connector on the charger (some of my chargers have them).
https://www.ebay.co.uk/itm/392234575792
Or something like that?
https://www.ebay.co.uk/itm/Long-600m...-/192635467491
Or this?
Only thing that might upset this is if you are using batteries with built in connectors, rather than 4 or 5mm tubes/bullets.
Images of connectors and the charger would be good!