A typical hobby charger just has two leads for charging, so you have to rig something up if you want to charge more than 1 battery at a time. A lot of people have done that, but I just charge one battery at a time. Charging one at a time is more brted-proof. You can charge in parallel or series. Some people have said charging in parallel works fine with li-ion because the cells sort of self-balance that way. The good thing about the leads is you can charge any length or any diameter cell you want.
Here’s the one I have:
It has an alarm if you hook something up wrong or if the leads don’t make contact, and it sounds when the charging is complete. It lets you charge to 4.1V or 4.2V. The maximum discharge rate is 1A, which is okay. I’ve been really impressed with it. It’s like a Maha C9000 for lithium ion batteries.
I will say that the precision of the display is to the nearest 100mA and doesn’t seem that great for 10440’s, but I may be imagining that. If you charge a 10440 at 400mA, it will terminate at 0.1 of that charge which would be 40mA, except I think it actually cuts off when it goes below 100mA and shows 0mA on the display. I haven’t tested that with a DMM to see if that is what is happening, but that’s what is going on with the display.