no mark …
it while it SHOULD terminate at 4.2V … there is a trickle charge current that can keep charging above that …
at the worst case with poorer quality cells they may vent … with good quality cells theyll get reduced lifetime
from probably the most respected tester and reviews or bats and chargers for lights
But there is a major problem, the charger has 20mA trickle current, in the above test I stoppen when the battery was up to about 4.30 volt.
For the next test I used a 4.35V battery and I modified my logging termination to stop at 4.38 volt.
Yes, the battery gets charged to 4.38 volt and would have been charged to more if I had continued.
This charge was running for about 35 hours to reach the 4.38 volt, i.e. it is not something that will happen just because the battery stays in the charger for a hour or two, but a day or two is very problematic.
The charger is a dumb charger, i.e. no microprocessor that needs to initialize or anything, when power is applied it will start charging immediatly. This type of charger works perfectly with a solar panel.
During all the upgrades to the charger it has gotten more powerful, but has lost the basic capabilities. The battery size is very limited and it will over charge batteries if they are left in the charger.
The over charge is not a problem if you are around and can remove the battery when the charger is finished, but if you let a battery stay in the charger for a day or more it can get serious (A cheap battery may vent, quality batteries will “just” loose lifetime).
The usb output works fine.
I will not recommend this charger anymore due to the over charge.
remember that a bat can easily loose 30% of its permanent capacity in ~300+ full cycles in perfect conditions

charging at 4.35v (which the tests show the miller 102 v7.01 can clearly reach) the life of a li-on bat is cut in half
in short the miller v7.01 can be dangerous with SOME cells, and can reduce the life of others …
and a few hundred cycles is EASILY achievable if your constantly using it as a powerbank both on the trail and at home
the good news is that it appears to be “fixed” in the newer versions
i mean for like a few bucks theres absolutely no reason to take the risk with the 7.01
especially not with BPLers who spends hundreds on cuben, patagucci and dead birds
it funny how folks go gaga over a bit of minor efficiency gain of a zebralight over a fenix (which we have shown to be untrue on the latest versions) …. yet say that overcharging at 4.38v (not to mention that the charger didnt stop there but would have kept increasing the voltage if it wasnt disconnected) on a li-on bat is of no concern
;)