Well, you might have better A/C than I do, but I think it gets too hot. The owner’s manual tells you to avoid full load on all 4 slots for too long, I think that’s somewhat telling.
What temperature would you say is hot? I’ve got a temp gun and cells I don’t care about, I’ll see where I can get it lol
In this case more than 50° Celsius is hot, measured with an infrarot thermometer. And I rarely discharge LiIon, with NiMH is no hot problem 
Temp here depends on the seasons 
Agreed, 45°C-50°C is a good max for cells to avoid really accelerated cell aging. I can accept 70°C for external temps for a plastic-cased device (won’t burn skin) as long as the highest internal temp isn’t much higher.
So much depends on where the temp is being measured, the thermal resistance of the path from the heat source to where the heat is being measured, and whether it’s the charger or the cell being measured.
If the temp is measured at 50°C*** but it has dropped by 100°C from the heat source to where it’s being measured (high thermal resistance path) then there is a big problem. If reading the heat source directly = 50°C then all is good.
The outside temp of a plastic-cased device can easily be 100°C lower than the junction temp of the hot components of a charger’s power supply or discharge circuitry. I’ve measured that, and worse, in chargers I’ve tested.
***making sure that 100% of the IR gun’s FOV is within the tiny area you want to measure.
Overall it´s hard to measure, I drift very slow over the cells and take a look at the max. temp.
The temp in the charger itself I can´t measure exactly, if I insert small cells I can maybe measure between the cells but it´s maybe not the place where are the discharge-resistors are located.
I hope the charger-designer and technicans test if their chargers are made for the max. discharge-current
I have the Vapcell S4+ and use all its functions. I want even more settings. Specifically, I want to:
You used all slots, max. discharge rate?
Xtar asked about the discharge function, can´t imagine they want to design a completely new charger.
Even if I hope they bring a charger with functions all other manufacturer already have 
Yeppers
OK, that will generate more heat than my 2x 1A
I don´t think it´s not critical for the cells, but in a passive cooled charger it´s getting very hot
Do you plan a new charger with discharge, current setting or you want to modify an existing charger which have already testing function?
Thanks for the comment. We are still working on it. If modifying the existing xtar chargers, which one and features you prefer?
I would vote for the VP4(L) Plus Dragon.
Because:
But a new charger in that/similar size with some other features would also welcome
Good list 
With this features it would be a very interesting charger I would buy instantly if not absoluty overpriced.
I know some chargers which have some or most of the features but not all.
Edit: Please don´t use the VC4SL for it, the NiMH-charge is to bad for me to buy it again, even it would have such features
I would also like (and be willing to pay for) a discharge function. Also, the ability to set the discharge current. For example, I do a lot of location sound recording, and the recorder I use is powered by 8 AA batteries. It draws a lot of power when I have 8 microphones. I would like to be able to test various batteries to see how long they will last in practical use in the field, when recording. So, I need to be able to discharge at 1200 ma to duplicat actual field conditions. I am not aware of any 8-bay analyzer/charger that provides that functionality.
Also, rather than have two separate 4-bay chargers that are packaged together, I would suggest to have an 8 bay charger that acts as a single charger. For example, it should be able to grade all 8 slots in one go. (Not just 4 slots at a time.)
Also, I’d like to see a charger that can charge at .5C in all 8 slots. For 2700mah AA batteries, that would be 1300 or 1400 ma. For AA NIMH batteries that power requirement is well within the capability of a 45W power supply. (500ma, UNADJUSTABLE, is just too little for a 2700mah AA NIMH cell!)
Thank you.
Regards,
DG
This is very good functionality to have. I use it quite a bit on my MC3000. I would welcome it on a less expensive charger.
A storage function that discharges to about 3.7 volts is great.
One that can be configurable to stop at a user assigned voltage, even better. I like to test cell capacity in accordance with the data sheets. These do have varying specifications for the lowest termination voltage and the current to use on discharge. So, good to be able to adjust these parameters.
Is there any 4x charger which allow it?
1A is the highest discharge setting for NiMH with a few chargers, most are not able to reach it. 1A is OK for me with AA-NiMH
Not sure if the Skyrc MC3000 can do 2A also with NiMH (all slots?), the NC2500 Pro can do 6x 1,5A but AFAIK you can´t set the slots individual (reminds me of Xtar )
We need to know what the VX4 can do
“Is there any 4x charger which allow it?”
I can charge at 1.5A with my Maha MH-C9000.
DG
I believe that it can. I use one of my C9000s for NiMH most of the time though. But the SkyRC MC3000 will definitely charge LiIon and NiMH cells at 3 amps for all slots at once.
EDIT:
If you are talking about DISCHARGE current, The MC3000 can do max 2A for all 4 slots at the same time with NiMH.
1 Amp with all 4 slots for LiIon cells.
Sorry about my misunderstanding.
Oops, sorry, I thought you mean discharge with 0.5C
Charge is not the biggest prob
C9000/C9000 Pro: 4x 2A (decrease because of heat possible)
Skyrc NC2200: Up to 2,2A/Slot if the IR is low
NC2500 Pro: 6x 2,5A if the IR is low
NC1600: 4x 1,5A (high for this small unit, I think it will get very hot) if the IR is low
Not sure about the Keeppower L4, I only tried 2x 2A for C and D cells, worked
Xtar Dragon: 2x 2A
UMS4 only in theory 4x 2A with NiMH, because of the slot sharing it´s effective 4x1A or 2x 2A
Agree 
atm it´s only on the Homepage of Xtar in the slideshow without details except “Coming soon”
