But the internal lithium plating most occurs during normal recharging.
See, at usual voltages, lithium plating can’t occur without extreme discharge currents(massive voltage drop).
However, at low voltages, it can become a problem since the reaction isn’t inhibited by the internal voltage potential.
It’s not an issue when sitting in storage at average temperatures. But, when charging back up at normal current levels, the huge current surge can induce a very short burst of lithium plating crystals, like what happens at high currents with tin whiskers during electroplating.
It’s why I’m planning to make this feature optional: if a cell below a voltage of 2,40V is recognized, you’ll have to proceed with charging manually.
No, protection circuits won’t do anything to prevent internal shorts from causing a cell to fail spectacularly. However, they do prevent over-discharge, which is one way those internal shorts can develop. Though, I suspect manufacturing defects to be a bigger issue for most users, and the protection circuit won’t help with that.
Attention should be given to the durability of the slider mechanism. Reading reviews on Amazon for the Opus BT-C3100, I came across a complaint that the sliders were connected with glue. A reviewer of another popular charger (I forget which) said the slider springs were breaking after about a year. If I’m buying a new charger I want it to be long-lived.
Good point. Wonder if it’s feasible to have a sliding rail that isn’t spring loaded. Instead, make the contacts be magnetic? That way there won’t be undue stress against the battery or sliders.
This brings to mind how a file-cabinet drawer’s back plate works. There’s a back plate that slides forward and back manually, with a lock. There is no spring. It keeps your files snug, no matter how loaded the drawer is.
IMO, some tweaks to the MC3000 would do the trick, so SkyRC could be the company to work with.
BTW: I guess you all know the story behind the MC3000? SkyRC built this charger to specifications of a flashlight enthusiast. Sounds like history repeating, somehow.
I worked out the probability that you’ll see anything from this project, and it turns out it’s only 2.718%.
Still, it’s fun to speculate what could be. IMO, the only thing that stands a chance of getting anywhere close to the requirements is a modified MC3000. Though, that would never get done on the budget requirement of $39-$49.
Group buys (like the recent one for the Xtar Li500S) make a lot more practical sense for a “budget” charger.
The only way a BLF charger would get done is to ask a company like Xtar to make some very minor modifications to an existing charger, and do a group buy. But that will never come close to the requirements for this project.
In HS and college science they teach that only the last digit is non-precise. So if I say I have 2.5 gal of gas, it’s understood it could be 2.48 or 2.54. But if you say you have 2.500 gallons of gas, then it’s a fact that it was measured to at least the hundredth of a gallon.
So when you say “I worked out the probability” and the answer is 2.718%… that is fascinating to me.
Yeah, something like a modified RC3000 is out of the picture.
@WalkIntoTheLight, as I’ve said before, if the additional features don’t work out, then the basic adaptable voltage charging(3,60-4,20) and very low current voltage recovery will be the only features implemented.
