Connect small wires to auto battery post?

time2roll’s first suggestion is good. I call those a “bus.”

If you really want to get creative, you can install a separate fuse block with enough spaces for each small circuit and then just run one wire to the battery to power the fuse block rather than all of the small wires. Of course the one wire will need to be large enough to handle the current draw of the combined small circuits and there should be a fuse capable of handling the load, but then each circuit is fused and you don't have a bunch of small wires attached to the battery cable. The advantage is that you can locate the fuse block anywhere that is convenient then. The disadvantage is more wiring and expense.

Many thanks for the ideas! I will look at them and decide which works out best.

While you're doing this adapting/modification, if the small wires don't have a fuse or circuit breaker in close proximity to the battery, add in an in-line fuse holder and an appropriately sized fuse to help prevent the possibility of a fire starting should they short out. (One important exception: the circuit for the emergency trailer breakaway brake system is often not be fused...and of course never should be switched.)

Any auto parts store will have an adapter that adds a wingnut connection. Should be like $5.

Unless they are wires that you anticipate having to take off periodically, just terminate the small wires with the appropriate sized ring terminals. Take the nut off of the terminals and put the ring terminals on. Replace the nut and tighten. No need for a spacer. If you have several small wires, you could also replace the bolt with a slightly longer one and do the same thing.

bob213 wrote:
This should work:post connector

If your battery has screw in side posts they make one for that as well.
Like these: side post adapters

These should work, the OP does not want to replace the battery cable ends.

bob213 wrote:
This should work:post connector

If your battery has screw in side posts they make one for that as well.
Like these: side post adapters

I could make one of those easy enough, a longer bolt, a brass spacer from Ace Hardware, and a nut. Interesting kludge.

I don't have a picture to show you, but before I added the auxiliary power connection panel to the coach battery, I went to the local auto store and they had these spade "Y" wire connector for top post batteries that the V part went under the thick battery cable and the other end had a screw terminal for lugs or wires. It's similar to what you are being shown above, but instead of a large battery cable clamp, it was a semi thick spade connector type with a second smaller post for attaching wires, spaded or ring connectors that didn't interfere with or required altering the original battery connector.

They also had a set that had two and three aux connections but at that stage, using a dedicated auxiliary power connection bar would have been better. If you have a side post, they had a similar set just for side post that had ring connectors instead of spade connectors.