How to generate endurance charges reliably without Enduring Cry?

I'm leveling up a Dex/Str point blank bow ranger whose goal is to avoid being one-shot (i.e. not a glass cannon) while not being an outright tank since it's supposed to be just outside melee range. It's a move-fast-and-blast-with-shotgun build (see the Ranger forum if you're interested). I'm at level 53 and I find that some areas are still pretty easy for me (e.g. Fellshrine) but on the other hand when several fast chaos-spitting cobras from the western forest get the jump on me, I can still die pretty easily (maybe I need a better totem...).

Since it looks like endurance charges are a pretty good way to mitigate chaos damage, I tried to see how I could get them, and so far I haven't found anything viable:

- Because of its taunt, Enduring Cry is not viable since I'm using a totem to draw attention away from me. It would make sense to have the totem cast Enduring Cry, but I don't have the totem gem yet.

- Meanwhile, my Warlord's Mark gem offers poor uptime, even at its level 13. Sometimes with luck I can get 3 charges, but they drop fast. Most of the time if feels like a chore to use Warlord's Mark. Besides I also really need Projectile Weakness, and Whispers of Doom is totally outside of my reach.

- The passives that extend charge duration don't seem that helpful and only one of them is easily within my reach anyway.

Is there another mechanism than Enduring Cry that can help sustain Endurance charges the way Blood Rage does for frenzy? I googled around, looked at the skilladril, and nothing too useful comes to mind. It sounds from PoE's official description of charges that some item passives might help, though I haven't seen any yet.

As far as Frenzy charges are concerned, in a few levels I'll have enough passive regen that I can comfortably keep Blood Rage on, and there's always the Frenzy attack as a fallback. Am I missing a way to likewise make endurance charges more than a random boost that's a chore to get?

There is a unique chest armor that generates an endurance charge for every critical strike.