Well, for AA and AAA cells it's acceptable. I've had no surprises charging my regular Eneloops with it, but I definitely prefer the BC-700 (set to 700mA) for them.
For Li-ions (I only have four EagleTac protected 3100mAh cells)... it totally gets the job done, but if those cells are down to 20%, expect charging to take a
long time. Some of Xtar's chargers go up to 1A, which would equate to just over 3 hours for fully discharged cells, but on the i4 v2, at 375mA, it can take about ten. That's why I tend to top off my cells often. Not ideal to always keep Li-ions at high charge, since this way they will not last as long, but it is nice to know I have full batteries when I need them.
I'm a cautious kind of person, and therefore I have a fire-alarm and powder extinguisher nearby the charger. The only real yet affordable way to put out a lithium fire though, is a large load of sand or salt to separate O from Li. Better safe than sorry, but it's a fine line to paranoia.
With that said... I do intend to replace the i4 with a more sophisticated, dedicated Li-ion charger
like the VP1 at some point. I will then give my i4 to someone along with a flashlight, as a present. It's a good charger, it's an affordable charger, it's a versatile charger, it's an easy charger, but it's not the best for either NiMH or Li-ion cells. Jack of all trades, master of none.
Oh, and one last thing about the i4: I've read several reports of Eneloop XXs getting very hot in this charger, so keep that in mind.
If you're looking for an easy charger that travels fairly well and charges all your cells, the i4 may be it. The Xtar XP4 and the ThruNite MCC-4 are the most direct competitors to the i4 v2 that I am currently aware of, so you might want to check those out too.
If you're looking for a great AA, AAA charger, go with the BC-700/BL-700/IPC-1L or the (Maha) PowerEx
MH-C9000.
If you're looking for a great Li-ion charger go with the Pila IBC or the Xtar VP1. Xtar has other options too, but they won't come with voltage indicators, like the WP6II (many cells), the WP2s (USB output for charging phones etc.).
Finally: almost everything I know I know from reading
HKJ's reviews,
selfbuilt's reviews and following the
flashlight reviews and
flashlight electronics sections on this forum.
Hope any of this is useful to you. :tired: