I have two EG4 batteries into a bussbar with 2/0 cable for expansion. The terminal on the battery isnt wide enough for the 2/0 ring terminal. Any ideas?
If the hole in the lug is the correct size for the bolt. You can narrow the sides of the lug to fit. The lug doesn't need to be wider than the matting surface of the terminal. That's all the contact surface available.
If the lug hole is larger than the bolt. You are losing contact area. This can generate heat at the connection point. It's best to use the correct size lug.
Any modifications done, should avoid degrading the connection.