wiring a second battery question

[sprkn_ranger]

Do it like this if you can:

BATT----FUSE------------------DIST BLOCK------------------FUSE----BATT

And if the wires coming out of the dist block are a smaller gauge then fuse those wires according to their amperage rating as close to the dist block as possible.

Edit- So if the main wire between batterys is 1/0 OFC then it should be fused to around 280-300 for the two fuses close to the batterys. And if you end up having 4awg coming out of the dist block, then that wire should be fused to about 100-125 as close to the dist block as possible.

I didn't know this, I have my amp directly to the rear battery, but my amp has a fuse. Should I still fuse it for safety?

The whole point of fusing is to protect the wire from shorting out and catching on fire and burning your car down (or the house if the car is in the garage!) so any positive lead coming off of any battery needs to be fused according to the wires rating. And if you have a dist block, the smaller wires coming out need to be fused because they have a smaller amperage capacity than the larger wire and won't pop the larger wire's fuse (assuming its fused properly)