A quad charger that had 2 bays 26800 capable and 2 that were 16340 capable would be cool.
The positive and negative terminals of s4+ charger are designed to better contact the battery
Can this design be continued in the future, or should it be improved? To fit more battery sizes
Is this a storage function or something else
If a Li-Ion cell is charged to about 80%, then the cell will last longer.
When not using a Li-Ion cell for a while, it can better if it's charged to about 80% for storage.
I'm sure Bort can explain it better than I can, though.
Thank you for your suggestion. This kind of battery is more suitable for fast charging of high current batteries instead of small batteries
The higher power of usb-pd is used in the charger. It is expected that there will be some difficulties, mainly in terms of cost, protocol and current distribution
18650 to 26800 works for me. I have plenty of chargers for smaller batteries. I only charge one or two batteries at a time, but a four slot with slot 1 & 4 for 26800 would work too. Storage voltage and 4.0v options would be nice, but not required for me. I can just check the voltage every now and then, lol. I do not like chargers that get really hot. High quality with whatever extras you think will sell best. Thanks for asking.
It could be improved by making the top part of the positive terminal a bit bigger, and by adding a small nipple on that big bit so that flat top 10440 and 14500 cells easily fit.
I managed to short a flat top 14500 cell in my S4+ charger and it left a burn mark on the insulation ring.
I agree that keeping a standard barrel plug (Or whatever is currently used) would be cheaper but I would like to see consolidation of power input ports from manufacturers across industries.
It’s not a deal breaker for me though, just something that’s nice to have. Ultimately you have to decide from a business perspective whether it’s worth pursuing.
Thank you for your support and advice
We will try our best to debug the charger so that the batteries of all sizes are in good contact
Thanks
80% power. Do you mean that the storage function sets 80 power?
Or do you stop charging when charging to about 4.0V in normal use?
I usually charge to full, but since 90% of my batteries are in storage at most times and not in actual use, they have less lifetime because they are stored full. Charging to 80% of energy (that is 4.0V?) will make them both suitable for storage and for normal use.
Come to think of it, my ideal setting would be 90% instead of 80, as a compromise between usability and battery lifetime. Maybe a charger could have user settings for 70, 80, and 90 ? 
Do you mean that the service life when I charge to 4.20V is much shorter than that when I charge to 80-90%? If not, there is no meaning. It is expected that the new charger will increase the storage function to 3.70v
If you need such a program, you need a very high-end charger to appear
It is equivalent to adjusting different charging voltages
Very advanced technology, seems not to have appeared in other chargers?
Thank you for your great advice
Do you have any pictures to illustrate what auxiliary accessories can charge a small battery?
thank you
I found this on batteryuniversity.com. I'm not sure how old this specific data is (which generation of batteries is used to generate these numbers?) but the article had its last update in nov 2021. It shows that for maximum service life you should charge to 3.95V (so not 3.7V as I always thought), but changing from 4.2V to 4.05V already more than doubles the service life of the battery.
| CHARGE LEVEL* (V/CELL) | DISCHARGE CYCLES | AVAILABLE STORED ENERGY ** |
|---|---|---|
| [4.30] | [150–250] | [110–115%] |
| 4.25 | 200–350 | 105–110% |
| 4.20 | 300–500 | 100% |
| 4.15 | 400–700 | 90–95% |
| 4.10 | 600–1,000 | 85–90% |
| 4.05 | 850–1,500 | 80–85% |
| 4.00 | 1,200–2,000 | 70–75% |
| 3.90 | 2,400–4,000 | 60–65% |
| 3.80 | See note | 35–40% |
| 3.70 | See note | 30% and less |
Table 4: Discharge cycles and capacity as a function of charge voltage limit
For me, support for small cells is irrelevant, and not needed.
Termination voltage is a requirement. I want to charge my batteries to 4.1V not all the way to 4.2. So, a configurable termination voltage. Note this is for a battery that is going to be used soon and is a different concept from storage voltage.
Some good suggestions. I really like the S4+, but it could use some improvements (don’t make it a MC3000!). BlueswordIM on here has some great ideas for a charger…
Support for 26800 batteries with charge rates up to 4-5 amps for the 6000 and 6800 mAh cells
Support for charge rates under 250 mA, like 100 to 150
Support for Hv li-ion 4.35 v and lifeP04
Storage mode at 3.6 to 3.7 volts
More accurate iR measurement…mine is about 50% higher than advertised (my Zanflare C4 charger does a lot better)
Make a separate display for each slot maybe? Ine that has all of the parameters: charge/discharge current, accumulated/discharge capacity, volts(realtime), iR
Manually selectable delta V for NiMH maybe? Some like that feature
Discharge current up to 1.5 A across all bays (fan cooling)
Keep the standard power input with the SMPS and 5.5x2.1mm connector. It’s lowering cost and works fine…don’t see a need for a $50 type C adapter.
This is all very intriguing! Thank you Vapcell, for listening to us. I really like how this thread is progressing. We each have different wants and needs. Most of what has been asked for has been mentioned several times for at least a decade. The key this time, will be in producing a charger that actually performs to spec through rigorous testing BEFORE releasing it into production… which is something several other manufacturers never seem to accomplish. Please… no more e-waste. Do it right the first time and sell thousands of chargers to us. Failing to do so will likely result in countless returns, disputes and bad press for your company. Xtar opened similar threads and I dont think they ever went anywhere. The MC3000 development was lead by a (now banned) sociopathic narcissistic, which reflected the end product.
My wish list:
1) Being able to manually set a termination voltage between 3.60V - 4.35V would serve the needs of the many. This would be particularly useful for preparing cells for storage. It takes time and effort to do it manually. Especially for those of us who own dozens of cells we cycle in a large rotation. Most of my quality name brand cells seem to come delivered at around 3.67V, so that is the voltage I charge them to for long term storage. A quick search reveals a wide rage of opinions, from 2.2-3.8V… none of which I would use as a storage voltage for the types of cells we typically use in flashlights (LCO, IMR, INR, NCR, ICR), unless stated differently in the manufacturer data sheet for a particular cell.
Also having the option to terminate at a lower voltage will greatly extend the service life of the cell, which is something I would do most of the time.
2) I will not buy a charger if there is a termination voltage variance between charging stations. Hopefully Vapcell can maintain voltage termination tolerances within +/- 0.002V. So PLEASE use quality components during construction. I will definitely pay more for precision charging that works correctly, and Vapcell could advertise this in their commitment to providing a charger built to a high standard. But the key here is that the charger must perform as advertised. 4 station chargers that show a cell voltage variation after charging of 4.21V, another at 4.20V and another at 4.19V, always get returned to the vendor. I dont have time to group my cells by termination voltage and its not something I enjoy doing. And yes, I check cell voltage after allowing my cells to rest overnight after being charged. As cells age, they begin to vary as they find their resting voltage, but not while they are still fairly new and in good condition.
3) If during your research and development, you are unable to maintain a consistent and accurate termination voltage between stations, I think there is a simple solution. Ive noticed that each station for most chargers seems to terminate at the same voltage most of the time. For example, if stations 1,2 and 3 terminate at 4.20V, and station 4 terminates at 4.18V, that will be the common scenario most of the time for that particular charger. A solution might be to included a user programmable offset to account for each station. Then the user could calibrate the variance and make them all terminate at 4.20V.
4) If the charger is capable of great precision while charging, maybe it could also report the cells resistance accurately. Again, being able to calibrate each station independently would hopefully allow a very high degree of repeatable precision.
All comments welcome!!