But they default to this irrespective of if it’s a 3400 mah 18650 or a 700 mah AAA … I don’t think it’s any indication of the best charge rate for a given battery …
Personally I consider 1C to be a happy medium between reasonable charge times / battery life and learnt this way before getting onto torches from flying RC Planes / drones with Lipo’s for many years
Thanks to everyone, I’ve read it all and appreciate it 
I think 1.5 amp is my new overnight setting, with the balls to set it to 3 amp if I am in a hurry. Since I am often just topping them off I expect it would only be at 3 amp for a short time before CV mode kicks in. And I agree, I would rather enjoy using them than charge slowly for a few more life cycles at their EOL.
Yes, that is the default. For AAA’s and smaller lithium ion batteries, I lower the current, and really because I don’t trust the stability of these smaller sizes, particularly smaller lithium ion batteries due to issues I’ve had with 14500’s in the past. My best charge rate is the easy charge rate. Ideally my chargers would have programmable defaults so I could dedicate them to certain cells, so I have to take more time on smaller batteries. Almost every time I throw a battery on the charger, charging faster has no benefits for me, and slight negatives. When I absolutely need to charge quickly, and none of my other hundreds of 18650’s are charged sufficiently, I crank up the current even if it means increased battery wear.
I charge my batteries as I need em so i charge at 2C or higher.
I charge 18650’s at 1A, 0.5A takes to long for me to stay around the charger although I have some old cells I do charge at 0.5A but I find it annoying. With my opus I charge em at 700mA when I got the time for it. I find it a nice compromise.
Based on the specs, it looks like charging the 30Q cells at 2 Amp shouldn’t be much of an issue, maybe at the expense of very slightly diminished life/capacity.
If I ever acquire a faster charger, I won’t hesitate to charge them at 2A. For now I’m stuck at 1A.
i charge mine regularly at 2A i dont mind losing life cycle they are cheap anyways but 3A when i am in hurry, i tried 4A but the cells got rather hot.
I could charge up to 8A (30Q max charging is 4A based on spec) and charge 8 18650(4S2P) at the same time if i want to but 3A is warm enough for the batteries and i dont usually need charging that fast.
Charging @4A as 4s pack.
Doing battery testing here we charge 30Q’s at 3A and over a handful of charges haven’t seen degradation. Of course over the long term you’ll see a little bit more degradation.
Samsung publishes that charging the entire battery at 4A you get 98% of the capacity that you get charging at 1.5A.
All of Samsung’s cycle life testing is done with charging at 4A so I can’t imagine it causes that huge of a difference in long term cycle life because if it did they’d probably want to publish cycle life with more normal charges.
At the same time, if you have time to charge at a lower charge rate it can never hurt.
that is good to know, but the heat generated @4A charging 30Q rather disconcerting though.
I normally just charge my 18650s and 26650s at 500mA. I’m rarely in any type of rush so I just throw them on the charger earlier in the day if I know I’m going to want fully charged batteries that night. I also figure that it’s easier on both the batteries and the charger. So, when I do charge at 1A or higher it feels super fast to me.
Ditto for me and overnight charging while rotating cells.
especially since they will age out before we wear them out.
that said i also charge all 18650 at 1a and 26650 at 2a.
i have plenty of spares so no rush.
Bought my very first batch of 30Q batteries. Put them on the LiitoKala Lii-500 for "NOR Test", more than 6 hours later, they are all terminated on between 3.6 and 3.8V, when I was expecting them to terminate close to 4.2V. Just want to make sure this is not normal???
If the “End” display is blinking, then they are still charging back up. And if so, what you’re seeing is the current charging voltage, not final. Once the “End” display stops blinking, this will be an indication that the re-charging has finished and you should see voltage close to 4.22.
I have SC4 charger and my 30Q charged up to 4.20 evenly.
I didn’t realise the “End” blinking display means it has not finished. Crappppppppppp! Now I got to do it all over again. Back in the charger all of them go. :person_facepalming:
But you already got your result (capacity), so all you need to do is just top them off at this point. No need to run the whole NOR Test again.
For an example how different charge/discharge currents can affect battery life, look here: https://batteryworkshop.msfc.nasa.gov/presentations/Perf_Safe_Test_Panasonic_Li-Ion_NCR_18650_Cells_JRead.pdf
Unfortunately it isn’t for 30Qs but gives a rough image how does it look .
I keep my cells around 3,90V and charge with 0.5A if I can plan in advance. If a fast charge is reqired, I use 2 amps. In extreme situations I can charge with 4Afrom hobby charger.
It’s interesting, but like you stated, it’s for an NCR cell which was not designed to handle high charge/discharge current. It would be nice to see how a high current INR cell such as the 30Q would do on such a test.
Not as extensive as the Pana tests but there are quite a few at the end of this Samsung INR18650-30Q datasheet
Cycle life - charge@4A discharge@15A, see page 8/17
Cycle life - charge@4A discharge@22A, see page 9/17