Bad driver, Bad Battery?

Perhaps this should be re stated as good driver exposes bad battery? I don’t really understand this and I wonder if someone might want to explain?

Will write more about how much I like the E02 II. However, I am very curious about one thing. I have an older eneloop and a few IKEA LADAs that really don’t work with this light. Here is what I don’t really understand:

Have a LADA 900 that when I put it into the E02 II will run on low or moonlight but if I go to high it will flash and then not run except for the moonlight modes. However, I can take that same battery and put it in the Ti3 and it works just fine. A layman might not even notice anything at all out of the ordinary. High is much brighter than low and moonlight is moonlight. I do notice that high is not as high as it ought to be but it isn’t all that bad. If I run it on high until it drops out of regulation it will take a 887 mAh charge and the run time is about normal. In one sense it seems the battery is good although the IR is definitely higher than it should be. (220 mOhms roughly as measured by miboxer C4)

Is it a bad driver in the E02 II or is it really a good driver that just doesn’t tolerate a marginal battery? I thought all Thrunites had regulated drivers but perhaps the Ti3 V2 doesn’t? Anyone care to broaden my understanding of drivers and how they interact with batteries of various qualities?

I have quite a few devices that won’t work with Ladda’s. e.g. Apple Magic Mouse 1, and a flashlight with Wights FET driver. Haven’t measured them yet, but maybe the voltage is slightly lower or something?
All other rechargeable batteries work fine.