How much life regen do you need to stop Blood Rage depleting life?

Depending on your build, and your play style, you can also use life leech to offset the degen. So long as you're leeching from enemies your health is good. If you're worried about a situation where you're taking damage and can't leech then it helps to have your blood rage gem in your weapon slot. All you need to do then to switch it off is quickly swap weapons and back again.

It's not uncommon for many builds to obtain the 3.6% regen nodes and leech the extra 0.4% from attacks.

You do have to be wary about accidentally having too much ES on gear which can cause additional degen that you don't want.