1 day left before feature freeze.
Will it have BeCu battery contacts? Silver plated ones? 
That would be lovely, but I doubt we’d be able to get BeCu C17200, even just nickel plated, although that would easily make it future proof for higher current draws(4A+).
Nickel plated brass would be a huge upgrade over the entire market, but that’s still just a hope.
About the BeCu springs though, I’m currently in the process of trying to find a domestic manufacturer to make a 2P3S/2P4S/2P5S battery holder, as the mold isn’t too expensive, and prototyping with a local company would be much easier.
This hot-rod needs some racing flames on the sides.
Hmmm, or do batteries and flames not go together? :person_facepalming:
Definitely interested. Will be watching development.
I’m definitely interested in this project 
As of late that is true but two of the best chargers ever made (aka quality charging across all supported battery types) and still available were made by Xtar so they know how to do it. VP4 Plus and SV2 both have adjustable charge rates and will charge any supported battery type correctly. There has been only about a dozen chargers ever that could claim this and 7 of them were made by Xtar. For me it has to be a great charger first. The VP4 Plus is also an analyzing charger, not the best but decent. Other options are SkyRC MC3000 and that is it. Unless you want to sacrifice quality charging across all supported battery types or loose functionality. If your OK with that you can add a few Opus models, a few GyrFalcon models, a LiitoKala and a Miboxer. As for quality I’d say Xtar is for the most part more reliable than most if not all consumer grade charges. If people were willing to pay decent money Xtar could surely make a quality charger that meets your requirements. Would they be willing to do it? No clue. I’d like to see SkyRC do a no holds barred update to the MC3000 but the cost would be unacceptably high. The above is based on my personal experiences and https://lygte-info.dk/ Round cell charger testing and reviews.
Just dropped by…
TL;DRed most.
Danger exists only in the eye of the moronholder beholder. ;-)
Cannot agree. There's people who may want to recover over-discharged cells while perfectly knowing what they're doing.
Place, for example, a li-ion cell on a crappy SK68 for amusement or testing. Or a couple cells on some crappy flashlight with lame buck driver. If I notice a cell just got over-discharged and my charger doesn't allows me to recover it, what do you think am I going to do?
Let people have options. This supposedly is an advanced custom charger. If pleasing the @#$% crowd is a priority, the potentially problematic advanced functions could be left accessible only after activating a special mode in some options menu or by pressing some specific key sequence. A warning message could then appear asking for activation consent.
The charger is going to have a dot matrix LCD screen, doesn't it? :-D
BlueSwordM, please fix this mess in the opening post. 
Yes, can we please have the first post updated with the final set of specs, as it stands today?
Thanks.
Great project idea. Interested!
Interested as well…
Final features that will probably be included:
1. Adjustable charging current (0,05-0,10A-…–3,0A) in 0,1A steps.
2. Support for multiple chemistries (NiMH, lithium-ion, lithium ion HV, LiFePO4).
3. Temperature monitoring (45C max below 2A, 60C max below 3A).
4. 4 cell channels, with support for AAA sized cells all the way to the largest 21700/26650/D cells up to 78mm length.
5. Active cooling if temperature exceeds 45C, and if all channels are active above 2,5A.
6. Full current cutoff according to charging current (10%).
7. 12V-20V input voltage compatibility.
8. Nickel coated phosphor bronze/brass rails for highest conductivity and accurate internal resistance measurement. Or just well plated nickel plated A3 steel if too expensive.
9. Internal resistance measurement.
10. Manual low voltage recovery for normal lithium-ion cells
Below 2,5V, maximum charge rate of 100mA.
Below 2,0V, maximum charge rate of 50mA.
Below 1,75V, it has to be manually activated.
Below 1,0V, maximum charge rate of at 25mA.
11. Adjustable max voltage for lithium ion charging: 3,65V-4,35V in 0,05V steps.
12. Storage charge mode: 3,6V. Lower would be better, but it is too low otherwise for most people.
13. Individual channel selection.
14. 4 button UI.
15. 100-200-350-500mA-1000mA discharging functionality.
16. Automatic charging current adjustment available.
Some extras that would be very nice, but not necessary if costs exceed 49$US with the below feature set.
- microSD card slot for graphs.
- Bluetooth functionality.
- Charging/discharging graphs to a USB drive.
Feature freeze will occur at 11:59PM EST.
Looks great.
Is there a price target for this? Or still too early to say?
39$US would be a superb price, but 49$US is more realistic.
That’s fairly reasonable.
I’d add reverse polarity protection, too, if not yet mentioned.
Yes of course.
It’s such a basic feature that I forgot to put it in.
How would it differentiate between NiMh and an over discharged 14500? Probably something simple that I’m overlooking otherwise the NiMh will be charging for a long time.
This is why I added manual to low voltage recovery.
Lexel and the other guy did have a point that even if my method is very safe, there is still a risk, even if it’s 0,00001%, so I decided to change it to a manual setting below 1,75V.
Dot matrix LCD screen? :-)
Now that I'm here I will say that for accurate internal resistance measurement cell voltage needs to be measured right at the battery terminals. I mean, a 4-wire setup like in battery testing holders (example). Give up on this @#$% being fully accurate otherwise.
