- Very effective if used as instructed ("read the manual" is recommended).
- Accepts nearly everything bigger than buttons or coins, incl. ~78mm protected 21700's.
- Display looks quirky at first: its 'clock face hand' icons are best for 'at a glance' viewing (it can be turned off with long-press of "Current" button).
- However in the "Charge mode" charge current is displayed in mA and internal resistance in milliohms, each to 4 digits, while in the "Store" mode voltage is displayed to 0.01v.
- Five charge current choices (0.25A, 0.5A, 1A, 2A and 3A) affect all slots, but as usual higher rates won't feed more than 1 or 2 slots at once, and it throttles all slots' current if high internal resistance is seen in any of the cells.
- "Store" mode discharges (or charges) LiIon cells to 3.7V, important to store or transport them safely. All chargers should have this! (Do you store cells at full charge? Yikes!)
- There's no mention of at what rate "Grade" mode discharges cells. It's been measured as fixed at 300mA, so the "Grade" mode can take >36 hours with high capacity cells.
- Older LiIon batteries are not refreshed by repeated charges/discharges like NiCad or NiMH, so the "Grade" function should be used sparingly.
- USB C-type power input is becoming a standard (goodbye to multiple wall warts and car cords, but not to overpriced cables). Oh well.

BTW - JK/Colorado, your 1A max current may be because the internal resistance of one or more of your batteries measured high - and that throttled all their charging currents. Check their IR in the "Charge" mode (tap the Mode button thru mA and mAh), then take out all the cells but the one with the lowest IR. See if you can select >1A with that one remaining cell (fingers-crossed)!

Absolutely one of the best chargers ever. Everyone should own one of these. Can't go wrong.

I use this charger predominately for 18650 and 21700 cells. Charger works great. UI is intuitive and easy to use. Only downside is 1A max charge rate (limited to 2 of the 4 bays) but I knew that going in. I have enough batteries in rotation that makes this a non-issue.