With all these firmware changes, makes me wonder what they know that we don't. In their defense, it's always tempting to tweak code endlessly to achieve better results. Would be nice if they posted what they changed/fixed with the new firmware.
A bit off both perhaps. They easily could have solved this by adding a tiny bump on the ends.
I wish Miboxer would have made the charger just a little bit longer. My 26650 cells do fit, but it takes quite a bit of force to get them in. Besides that such a thing doesn’t feel professional, I wonder what kind of wear it causes.
Can the user upgrade the firmware.
I really would like an upgrade that keeps the settings at 3A permanently. All cells I charge in it are 3500+ mAh.
Now I have to play with the settings every time I put in a cell.
Miboxer is raising the height of the bottom bump a tiny bit. That should fix that situation.
What do you mean it doesn’t feel professional? Do you mean the sliders don’t feel perfectly smooth?
You’re not really causing any wear. You are basically just stretching a spring. It might be possible for the plastic tab that holds the spring to break, but it’s unlikely. I have had that tab brake on other brands of chargers, but I was able to fix it without much problem.
Why do you have to manually set it every time? Usually my Liitokala 26650 cells auto set to 2.90A or 3A anyway. Setting them manually is not that big a deal and is normal for all chargers.
It would not be considered safe to program it to automatically choose the 3A setting for every battery. No battery charger uses 3A as the default setting.
By not professional I mean that I have to force it in.
BTW that’s only so with my 26650 cells, the 18650’s are a better fit.
I’m wondering if 21700 cells fit.
I just would prefer a quarter inch more space, that’s all.
I agree with you. However, if I recall correctly there are quite some users who just wish there was no “smart-internal-resistance-check-and-auto-adjust-current-feature” in the C4-12. Especially, when using button top cells (soldered or joint-welded) or in combination with protection circuits, this smart auto-detect feature is more or less a nuisance. So, I’d recommend MiBoxer to integrate a hidden expert/advanced “use-at-your-own-risk” mode that can be triggered by multiple button presses or whatever. That would enable users to choose whatever mode they like to use and have their cells charged with ludicrous speed. :smiling_imp:
I bought this charger especially for 26650 cells, so they don’t take long to charge.
It was the 3A rating I bought this charger for, but when I put in a 26650 cell and check the amps it usually is charging with 0.7-1.5 amps.
When did you check the charging current? Right after you have put the batteries into the charger or 10-15 minutes later? Usually, these smart chargers sense the internal resistance, start with low current and increase it if everything’s alright. I doubt there’s any charger at all that auto sets to 3A as this charging current is way too high for a lot of batteries.
Best would be to keep an eye on the internal resistance indicated in the charger. Make sure it is as low as possible by cleaning all contact areas before and by turning, re-inserting or dangling the battery in the charging slot until you get a reasonable number on the display. Once you have values of 200-999mOhms you don’t have to expect this charger to auto set the current to 3A. My C4-12 had real problems with button top cells and I got values between 320 to 999mOhms, i.e. a pre-selected charge rate of 0.00-0.15A.
Once I insert a cell I watch the display cycle. The first charge rate is usually too low, on the 2nd cycle it’s gets higher, then the 3rd cycle it typically sets. So maybe check it 30 secs after inserting to see what it settles on.
It also needs to see that low internal resistance to set at 3A automatically.
It also needs to be below 4v initially to use the “constant current” charging mode.
That’s the same problem Mikeadoo had. It turns out the button tops were not welded securely enough. Removing the button tops an adding solder blobs fixed it. I suspect that soldering the button tops might also work, but I have not tried this yet.
It does seem to be related to button tops, though.
The circuitry and software in the C4-12 that determines the internal resistance is very finicky. Maybe more sensitive than other brands of chargers, hence why Miboxer might be doing these small software changes to improve this.
Also, I wouldn’t really say your other charger gets the resistance right, but that it gives a more stable and reliable reading then the C4-12. Accurate internal resistance is a very difficult thing to measure due to the tiny units we use, milliohms.
