Help picking new batteries!

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Update Pany B's came in. All look genuine (as far as i know) they were at 3.6 -3.63 V on arrival, full charge on xtar VP2 shows 4.2 and when read with Fluke they are all at 4.196 and 4.197 hot off the charger.
I really need to get some equip to measure capacity but thats the best i can do for now. I can check the voltage again in a day to see how much it settles. Would this be any indication of battery health?

 

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Left two to sit for a day and they hovering around 4.165V same as my two year old orbtronic, (charged it same time and checked with new ones for a reference). I've got the other two new pany b's in convoy s2+'s running one at 40% of max (2.8A) in one. And 20% of max in the other (2.8A also). At two hours the one running at 40% read 3.54V and the one running at 20% read 3.73! Still got them running to check on undervoltage protection but all signs seem to point to being genuine pany b's (in my very limited experience). Just thought folks might enjoy an observation.

 

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S2+, T6-4C, 7135×8-- ran for 2 hours and 50 minutes at approx 40% brightness before starting to blink, battery was at 2.997V. Is this runtime about right for the convoys on a 3400mah battery?


I figure 3400mah= 3.4A for 1 hour.
Max for s2 is 2.8A, at 40% should be about 1.12A
3.4÷1.12= 3.03, or a hair over 3 hours.

Is this logic correct?

 

[ven]

They will more than likely be genuine GRAY so would not be concerned. The only negative with the pany B really is age, these cells are getting on a bit now. Also there are better cells(sanyo GA to name one) available, with a higher amp rating and higher mah rating. It is normal for the cell voltage to drop slightly after the initial charge, this is a variable of course. Ideally calibrate your MM with charger, so you know if there is a voltage read out difference, to apply it.

 

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They will more than likely be genuine GRAY so would not be concerned. The only negative with the pany B really is age, these cells are getting on a bit now. Also there are better cells(sanyo GA to name one) available, with a higher amp rating and higher mah rating. It is normal for the cell voltage to drop slightly after the initial charge, this is a variable of course. Ideally calibrate your MM with charger, so you know if there is a voltage read out difference, to apply it.

Thanks again ven! I figured they were legit when i bought them but with all the cells running around that are fake i couldnt let my wife use them without checking them out and confirming as much as i could. I know the V will settle, i was just wondering if u could use it as an indicator. Like if it settles from 4.16 today to 4.0 tomorrow, i would think its a problem but didnt know if that was a value i could watch and get solid info from.

I do plan to get some GA's (based on your and others recommend) when i pick up or mod something that pulls more amps.

I been checking the MM, charger, and the battery indicator on my MH20 together, they are dead on with each other. It actually surprised me how close they were. Within .01 of each other!

 

[ven]

They will drop slightly but only slightly over a day or so. If like you wrote, 4.16v today, 4v tomorrow then yes recycle as junk. Usually say 4.2v, should not really drop bellow 4.18v after sitting for a while. After the small initial drop, it should hold voltage very well. Over use , charging,discharging the IR increases with age, not much we can do about that, only limit or keep it to its minimum by following basics.

Cool, just do periodical checks once they pas your initial checks............i check maybe every 3-6m with MM

 

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They will drop slightly but only slightly over a day or so. If like you wrote, 4.16v today, 4v tomorrow then yes recycle as junk. Usually say 4.2v, should not really drop bellow 4.18v after sitting for a while. After the small initial drop, it should hold voltage very well. Over use , charging,discharging the IR increases with age, not much we can do about that, only limit or keep it to its minimum by following basics.

Cool, just do periodical checks once they pas your initial checks............i check maybe every 3-6m with MM

You're always so helpful ven!! I really appreciate all the replies and knowledge you share!! I don't do any social media stuff. But peeps like you are why i joined forums finally! That said, one more question LOL!

Do you have any recommendations for a charge-discharge "cycler" to determine mah? I dont really need another charger but it seems to me that this is the easiest way to go about it but if there is something better let me know. Thanks!

 

[ven]

Your welcome GRAY, charge/discharge there are a few decent chargers, range in cost. I have been using the opus bt c3100 v2.2 for a while now, never missed a beat and gets used every day of the week! This has several modes

charge
discharge
discharge refresh
charge test
quick test

Rates from 0.2a up to 2a on bays 1+4 so pretty flexible there, also nimh support and 4.35v charge if you open up the underneath of the case. Dont ask me why, but inside is a switch to change the V, 4.2v/4.37v/3.7v. 4.2v is the norm, so its showing termination voltages to select.

Want to spend more and be king! The SKYRC MC3000, does everything including making you a brew! However, QC does seem a little hit/miss on the early versions regarding quality of components/plastics. If you do invest, make sure a latest model. So thats 2 chargers, there is xtar dragon, looks a solid very nice bit of kit. Down side for me is simply no easy voltage readout, its in % which i do not want. Also not any low charge rates, so no good for my smaller cells.

The opus bt c3100 can be bought for around $30, 1/2 the cost of the dragon, 1/3 of the skyrc cost. I think it offers decent bang for buck, so going off my use and how its been, i can easily recommend the opus.

To get the mah reading, the charger needs to discharge down to (example 2.8v but is a variable , so not all will be bang on the money) then back up to 4.2v. That is a rough guide to the mah reading, sure battery/charger experts can add far more. So just a rough idea............

Its a sloooooooooooow process, even if you set the discharge value quite high.

 

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Awesome!! I agree, i want V readout not percentages.

I'm sure it is like watching water boil. I usually charge my 18650's at .25A, so i figured it would take forever. I like to have all in one things when i can get them but if it compromises another qaulity/spec im looking for then i'll buy seperate items. I need to figure out my future needs at the moment before i run amok buying stuff that i wish i would have waited on but these are great suggestions. Especially the btc3100, sounds like it'll cover my needs for now and is affordable enough i won't feel like its a waste if i upgrade later. :bow:

 

[ven]

0.25a is too low GRAY, if its those pany B cells, 1a is fine and should not take all day!

 

[ven]

I have been pondering for ever(feels like that anyway) and i just cant find a charger more suited still. If my opus packed in today, guess what charger i would get again in a heart beat.......no question! I dont need all the little modes, although some would be useful i guess. Still i have coped all this time without a 3a charge rate, most of my vape cells(dual as i use 2) get topped off on 1.5a, or my 20700 at 2a.

My charge rates(some are conservative, but this is what i use)
Nimh, eneloop
AAA -0.5 or 0.7a
AA -1a
4.2v fuel
10180- 0.01a
10440-0.3a
14500 and 16340 -0.5a
18650- 1a-2a
20700-2a
26650 -2a

4.35v fuel(so 16650 mainly) 1a

 

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Thanks again! All my 18650's are pany b's. Few years back when i started researching all the lithium stuff i thought i read somewhere that charging at 1A was fine but lower rates could slow the IR problem you mentioned earlier. Certainly, the cells will degrade no matter what but if above is wrong, i'll charge at 1A all the time. I'm not saying i don't ever do it but most of the time i'm in no hurry for a cell and the Xtar starts at .25 so i just leave it. Im looking more and more into battery chemistries now that im trying to get into solar stuff. Pretty sure that some cells can actually benefit from a higher charge rate but im not 100%. Maybe thats the case with the pany b's? Ima check it out when i get time.

 

[ven]

Pany B are fine at 1a, i still have some which must be 7+yrs old now and holding charge etc . Newer chemistry(hybrid ) have a max charge rate of 3 or even 4a on some cells. My mind set is, if i need to charge quick and use 2 or 3a because I need it fast, get another cell and charge at a lower rate. Although cells have max charge and discharge rates, using them to their max specs will shorten their cycle life. Its very rare i actually do a full cycle, so discharge down to 3v(min spec can be 2.5-2.8v variable depending on cell) and then back to 4.2v. I call it topping off, as voltage can be anywhere from 3.3v to 3.8v back to 4.2v. So a part cycle if makes sense. Not exact science, no crazy in depth studies here! besides life being too short as it is, i just use my stuff but take note of voltages being used.

Your biggest problem is cell age, pany B cells are getting on a bit and not sure when last manufactured. So they could be 3yrs old or 6yrs old(example).If stored for that time, correct temps etc etc(good conditions , correct storage V) then i am sure the IR will be limited . Certainly compared to being stored low or at 4.2v anyway.

Its good to have interest, but use them and enjoy them, good cells are pretty cheap these days so nothing really lost if you get 3yrs of good use ,or 4 . Thats me though, everyone is different which i respect

If you want precise info, scientific etc i am not your man, i just use them ,but look after them as best as i can.

If your concerned with the pany B, maybe with them being an ageing cell, charging at 0.5a would certainly be fine.

Some great solar set ups on here, i would like to get into them a little as well, my issue is living in the UK :laughing: Maybe wind or rain powered chargers:thinking:

 

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Guess im a topper offer too. Usually around 3.6, then i'll charge. And yes, partial cycles make sense.

I am a little too interested when thinking about how stuff is made, or data sheets, or material science blah blah... thats just me, but i don't expect anyone else to put themselves through that. At the same time i'm really hard on anything i own and even after researching what the best cell is and how to take the best care of it i'll leave it in a car in the middle of summer at 4.2V for storage lol. Even if i don't follow best practice i still want to know it, idk if thats makes me dumb or weird but i'll take it :tinfoil:!!!If i get two years out of my batteries i'll be happy lol.

When i want precise scientific info, i go to a technical site to look up factual lab tests (even then i'm picking apart all the variables of their testing and asking what if and how come lol) When i want real world experience from someone who cares about product quality and likes to share their thoughts and opinions based on their own research, i come to forums. Alot of my research starts in the forums and i'll pick out a bunch of keywords then start studying them. The more i read the more the pieces start to fit together, then once i have an understanding i can apply what i've learned to my current needs and make an informed decision. I'm a different animal, i'll give ya that, but don't worry about me enjoying it. Im just as happy studying batteries as i am using or conversing about them. Thats just me though and im glad you are respectful of that! Just as im respectful of someone who doesn't know any better picking up 9000mah cells and saying they are the best even though i've informed them otherwise. If they know the dangers and the shortfalls and still choose to save a few $ now instead of thinking ahead about dangers and long term value, it's still their money lol.

I'm sure there is some great solar stuff on here. I'm impressed by the members of the DIY community here and elsewhere on the net. Creativity and Basement Engineering can sometimes rival or even surpass masters of the craft that have much more R&D and equipment invested.

Im kinda in the same boat though, WV is not top of the list for U.S. based solar power lol. I'm better off building a coal fired charger lol!

 

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Glad i waited to order some unprotected GA's. Ordered 4 for 19.99 at GB today!