i just asked the rep from vapcell store on AE to ask his boss about the firmware situation, lets see what he says.
yes they are crap, very old/fake batteries, and i just wanted to test it out and see how bad it is. but if i dont trust the resistance reported by the charger, then how can i trust everything else reported by it?
im not pressing too many buttons, im literally pressing display to switch slots, and then once on ch 4, i pressed mode to go to cap test, thats it. even in second video, im still just alternating between slots. my finding is confusing because it is confusing, thats why i posted this thread in the first place, im confused by it. but now i kind of see a pattern, the higher the resistance, the shitter the battery, the more likely it doesnt have the capacity as rated on the wrapper
The short answer is volts and capacity is pretty easy to calculate reliably.
Resistance changes based on the contact resistance between the sliding terminals, the oxidation on both the terminals and the battery, the temperature of the battery, the charge state of the battery, the calculation the device uses, the amount of load used to calculate, etc. No two manufacturers do any of this with any consistency between each other, between slots, between batteries. It’s just a rough calculation at best. It’s probably good enough as an alert to the user to say: “wow this is high compared to a known good battery measured in the same charger, let me investigate further”
Try this as a test:
Insert a battery as normal, record resistance, remove battery.
Next, take a qtip and clean the terminals on the charger and battery with alcohol and then when you insert the battery press on the back of the terminal to add a little pressure until you see a resistance value. I can almost guarantee it will go down, maybe even significantly, regardless of what battery you put in there.
Resistance > on any charger with a slider it’s ‘approximate’ at best. It’s totally dependent on contact resistance and with the sliders there can be huge variation even with the same battery, in the same slot, over multiple tries. The “number” it gives you cannot be readily compared to other charges, or the more accurate methods of testing.
In general, as the resistance goes up, the capacity and quality go down. BUT, you are using THAT measuring tool on THAT battery. It’s not a ‘standard’, it’s just a reference. I finally gave up using that feature on chargers, and got a dedicated discharge+resistance tester that is pretty reliable (reproducible) and seems to be accurate.
ANY 18650 that claims more than 3500mAh is crap…period. Even top end brand name batteries claiming that capacity rarely actually achieve it. The higher the claim, probably the worse it is.
so i just re tried all the batteries i tested yesterday in all different slots after doing the alcohol swab thing. for the most part, its fairly accurate still, 40-50 still stayed around 40-50, 100-120 still stayed around 100-120, but one out of the two batteries that were rated for 4200, yesterday it was 221, today its down to 30-40, lowest try was 19! no other batteries went that low. i tried it quite a few times, all 20-40 ish. i think its just messed up. im expecting it should be around 100-120 like the other 4200 one, but i dont know…either way, not using it, cuz if what you guys say is true, that volt and capacity numbers are accurate, then this one only has 126 mah LOL.
I keep a few of the ‘not horrible’ cells around. They are useful for testing low voltage cut-off, practice soldering, and other battery abuses you prefer to not destroy good cells over.
Emphasis on not being dangerous here, just not very good.
i dont think i will have that need, doing cap test with s4+ already makes me feel like an electrical engineer, even tho im literally just pressing a few buttons, hahahahaha
hm, i wonder why only the outer 2 slots are designed with 1a discharge, while inner 2 only 0.5a…this is killing my ocd when i try to do cap test for 4 identical batteries
I have an Opus. It has a fan. The fan whines and lots of people hate it. But, it does help cool the system so it can discharge more banks at a higher rate. Even so I have an 80mm PC fan pointed at it during higher work levels. Small USB powered fans or laptop coolers can work well too.
Easy to set up if you have some 6-12v power bricks from another device. That’s what I did.
In fact, a 120mm PC case fan is cooling my fridge compressor coils powered by a 12v wall wart. Fan died and a replacement was $350 for a tiny damn FAN! PC fan works fine. cost me $12.
Anything over quite warm is hard on batteries. Too hot to hold, it simply too hot.
All batteries last longer if kept cool. They may perform better when warm > hot via increased chemical reaction, but that is ultimately at the expense of longevity.
Power bricks/wall warts > those little black power adapters for various devices, like the one powering your charger.
Some people just have them around in a box from old devices that have been tossed. If you don’t, small USB powered personal cooling fans are pretty cheap.
Fans pull very little amperage. You just need a ‘brick’ from 6v-12v. PC fans are 12v. They will run from 6v>12v; slower, quieter, but with less air movement at 6v.
Cut the plug adapter barrel off the brick, cut the fan wire plug off, and wire red>red, black>black. Other wires can be ignored as for PC fans they are speed control info for the motherboard.
Note - if you have a PC recycle shop around they often have boxes of them for cheap. I’ve gotten replacement power supplies (upgrades) for chargers from a recycle shop. I bring the charger body in to make sure the plug fits, make sure the voltage is right, and the amperage is more than specified. The device will only use the amperage required. My Opus came with a 12v/2A power brick, which is NOT GOOD ENOUGH. It now runs on 12v/3A and runs fine with a new adapter.
I have my Opus sitting on top of a PC fan and is powered by a PC power supply. Easy enough to wire the power supply to supply 12v, 5v, and 3.3v. Both were salvaged from a desktop that I was getting rid of.
