just brought some new 35Es from banggood, i have 2 questions.
1. there seems to be a clear plastic wrap on it, not covering the 2 ends, can still use it, should i take them off? i dont know if it makes any difference for anything, first time buying battery separately, never had this kinda wrap on batteries that come with lights
2. i already posted this in another thread, so ima just copy and paste
“i just got a whole bunch of 35Es, and i put them in to charge and do cap test, i noticed that the amperage at which s4+ automatically determines for them to charge at are all different, some are 1A, some 1.5A, some 2A, and this is just from the first batch of 4! how does the s4+ determine that? i know it automatically decreases gradually as the battery is charged full, but i dont think thats what this is, because they were all around 80-90% capacity”
i just wanna add that, the resistance measures were different too, not in same ball park like the sofirn 18650s that i got, they were all around 40-50, but these, at least the first 4 (i got 8), they were ranging from 30s to 80s. i mean i know some people said the resistance measurements on chargers isnt always accurate, but i just wanted to mention that in case s4+ takes that into consideration when deciding the charging amperage.
I’m fairly certain that the automatic charge rate is driven off of the measured internal resistance. Lower resistance would usually indicate that a cell could be charged at a higher rate. That’s why the manual mode is handy - I switch to that when I want to override what the S4+ decided to do.
Link or picture to your 35E’s? If they’re unprotected flat tops, you usually wouldn’t have that clear wrapper. You usually find that on protected and/or button top cells. It’s used to hold the protection circuit and/or button in place.
Yeah, that could’ve been unfortunate. Though the cell would still be perfectly usable - the circuit would just come loose and you’d have an unprotected cell instead.
This can be handy to know in case the protection circuit fails or adds too much resistance. The cell underneath might still be fine, so you could remove it and check.
i actually just realized i bought the wrong cells…i saw these on sale, i thought my gimbal can take them, but it looks like it takes flat tops unprotected, so…i guess gotta find some other use for these
If you wish, you could unwrap them and remove the protection circuit. It’s probably either just sitting there or maybe has a little spot weld to hold in place. If it’s welded, you could likely rip it off with your bare hands and hit the terminal with a little sand paper or a file to make sure it’s smooth.
Why would your gimbal require unprotected flat tops? Did you try them? The primary difference would be a longer cell, and with the extra wrap, a fatter cell, with somewhat lower discharge capability.
Mostly the real world use is not any different.
Note - the protection is one more layer of resistance and is contributing to the charger’s automatic charge determination.
ya its purely the length issue, this is what happened before when i used batteries that didnt come with the gimbal, i didnt know about different lengths, so i just twisted the tail cap tight by force.
ironically though, even the ones that came with the gimbal had a similar issue, just not AS bad as this one. both were button top unprotected, but these blue ones were slightly longer for some reason. but ya, thats why im thinking i should just use flat tops for this gimbal.
damn…i dont know if i got fakes or not, but i just tested the first 4 with my s4+, and the highest one was 3300mah, the other 3 are all 2600-2800mah, wtf? these are supposed to be rated 3500mah!
Oww, that battery really got punched! Compartment is THAT tight?
The 35E appear to be almost 70mm. Samsung 35E 18650 3500mAh 8A Battery - Protected Button Top - IMR Batteries
Where did you get them and what did they cost? Vendor reliability can make a big difference in battery/charger/light purchases. The amount of fakes is simply daunting. I know Canada has issues getting this kind of stuff.
(Hey, at least your medical system is not complete mess.)
Once again, I encourage you to NOT use automatic testing. Set it up manually so you have some known control over the test. Charge them however you want. Discharge them at no greater than 0.5A. It’ll take awhile.
Even lithium’s that have been sitting around for a good while can benefit from a couple cycles. It’s less of a ‘refresh’ than a chemical ‘wake up’.
- charging 4x 18650 up to 100% 4.20V on the S4+ using Auto
- putting them in an XTAR VP2 to top them up from 4.17V to 4.20V (S4+ terminates early?)
putting them back in the S4+ and running Cap test in Auto
Slot 1 and 4 usually finish faster when the internal resistance across each cell is similar due to 1A discharge.
I’ll try 0.5A discharge via Cap test. Perhaps that’ll give a better real world capacity if the current used by a flashlight isn’t much higher than 0.5A for general use…
ya, thats not from the tail cap tho, its from the other battery, cuz it takes two, so when i jam close the tail cap, which doesnt have a spring, it pushes the back battery, which pushes into the front battery, and, well, i imagine it felt like an unwelcomed anal for the front battery lol.
i got these from BG, 17.99 for 4, i will try your manual method with them later, if still the same result, (which i think it will be, because the 3 thats lower than 3000 were all auto discharged at 0.5A) i will dispute with the BG CS, see if i can get a free return, 3300 i MAY be able to let it slide, but 2800 or even 2600 for a 3500, thats just too much
Mmmm, I’d be somewhat suspicious of ANY battery from BG. They absolutely do NOT know what they are doing in that department. They are like Amazon.
Out of curiosity, what is the gimbal? It needs 2x 18650 to run?
I’ve had a few (very few) problems with BG over years, so I’m not hostile toward them. Having said that, sending ANYTHING back from the USA to China is SO DAMN EXPENSIVE it absolutely wipes out any marginal cheap benefit from buying from them. I’ve not bothered. I’ve gotten a LOT more selective with what I buy. If there is even a remote chance I need to return it, I don’t buy it. I literally need to be willing to trash it before I buy it.
hm…but if its their problem with the battery, then im gonna make them pay for the shipping back, or just refund me and let me keep these fakes, or maybe poor binned ones, i dont even know what they are.
I’ve never had a case where I could/would send something back, though they tried to get me to do that. They sent me someone else’s order-a BUNCH of nail polish and other similar stuff. They wanted me to buy it or send it back. I don’t know any women that would want what was in that order. I would not do either since it absolutely was not my fault. They finally gave in and sent my original order. I’ve also had good resolution with them ultimately. Occasionally takes a bit of negotiation.
Just got one of those foaming electric soap dispensers from them; Blitzwolf, generally an OK brand and pretty safe if not top end. Battery clips broke first time, motor won’t run. Useless. Guess I see what they will do with that.