I have an idea that your plan to provide unlimited power to your TINI is not going to happen.
The PB2 will not charge up the TINI nor the TIP let alone provide prolonged power.
Is there similar charger/powerbank for 18650 (two ideally but one or three would be fine, maybe 4 if not too big ) which does not cut power to lower current devices? All I found are open/naked batteries… Or not good powerbank.
I got a TOMO Epilot E4 (4-bay 18650 powerbank/charger), testing low current load - I first tried charging a Mi Band 2 watch (USB meter registers 0.05A charging current), it doesn’t shut down. Then I tested using a USB load tester, doesn’t shut down at 0.05A, but it will shut off after several seconds of 0.04A. So the low-current-load shut-off for this Epilot E4 is around 40mA (0.04A).
As additional test, I tried using solar USB charger with the Tomo Epilot E4 — it seems to continue charging even though voltages are low (eg. USB input voltage of USB solar panel charger is below 4.0v, though of course, charging current is very low, like 0.01A only), but still it seems to mean that this powerbank/charger is also compatible with USB solar panel charger (where voltage can dip low and resume when voltage goes back up — I don’t have more accurate equipment to test more in-depth though.
I’m considering one, but have seen allusions that it prematurely cuts off in the ninety-percent range and doesn’t fully charge them to 100%, presumably because of the low current detection.
Also a bit unsure of how modern iPhones handle DCP coded chargers. Not a big deal if it’s not the full 2.4A, but 1.5A isn’t as desirable.
One of these would tick a lot of boxes for an upcoming trip. Not eager to buy another dedicated power bank that will mostly sit in a draw and rot, like my last one did, since I don’t use them often. My 18650 cell collection is all flat-top and unprotected, so no issues there.