balance charging 18650's / 26650's

Batteries and Chargers Chargers
21

now we are getting to the good stuff, can we mix diffrent mah rated batteries.

there is two lines of thought here, one is its only the end voltage that matters and the other line of thought is no dont mix cells, or you will explode and go to hell.

am little example when parrallel ballance charging lipo battery packs that are made up in series (say all 2s 7.4v 2s1p) with a parrallel ballance board you can mix mah rated batteries (say 1750 mah & 2200 mah ) as the charger will only see the end voltage of 4.2v per cell, so as long as they all have the same end voltage its fine.

now since we are making li-ion series packs i think you should be able to do the same, mix mah rating as when the battery is full it will read 4.2v or close to, i tryed to use all the same brand but when you test the batteries seperatly they all have slightly diffrent internal resistance and mah rating so its kind of same same or yes but no, if that makes sence, and i have mixed brands and mah ratings with the balance set ups ive made sofar.

i have not tryed to mix diffrent batteries like 18650,s and 18350,s as i only use 18650,s this far, but it all should be ok as long as they have the same end voltage, i have and will charge diffrent mah rated batteries together as long as they are the same cell count and same end voltage, another reason why i think balance charging is safer.

with series charging the gap in the voltage is not a big deal there can be more then 1 volt no problem, it just might take a little longer to ballance charge, but when balance charging group,s your saving alot of time so its all good but with parrallel charging i would not atempt this though.

i my honest opinion there is no pointbreaking in or cycling li-ions or lipo,s, they will improve after a few charges but thats it, they dont need to be cycled and the best way to cycle them is charge them when you first get them and then to use them and then charge them and keep going, i belive cycling batteries was and is only needed for nicad,s as they do have momory the lithium based batteries dont need to be cycled or broken in so to speak as theya re diffeent chemistry and no memory.

and yes hyperion make realy good chargers ! ive used a couple but have not owned one as im a tight arse, i do like the ichargers they are middle range, not the best but much better then most, but people will always go for the 25 dollar charger and i can not even talk people into spending 80 to 100 dollars on charger,

22

Good info man, Thanks!

Just out of safety reasons im not gonna mix 18650's and 18350's, just in case. But 18650's with larger cell gaps ill do and also do a trial run with 3 of the same cells and 1 different one of a different capacity and see how it goes before i mix them too much. I recognize what alot of people miss, Especially those who think they can parallel 10 cells all at once and says its better than series balancing. With the series balancing the charger see each cell separately and adjusts its output to the cells needs in correlation to the other cells.

But parallel charging a bank of 10 cells is like just charging 1 large battery and the inconsistency would be horrible imo.

I think ill still run a 3 cycle break-in on new cells as i do see an improvement, Also with so many lights and cells i have it could take forever before the cell even gets used once let alone 5 times to be recharged.

I just threw the plug for the Hyperion into the mix as its one thats never mentioned, Mainly due to price. But for the accuracy and extra charging options along with 100% software controlled its price seems small for what you get. But ill be the first to admit that $40 balancing chargers can do the same job most likely just as well, But to get software control the price jumps up alot. Mine was a "Special Treat" item to myself as i knew id be using it so much that i wanted one that did everything i could dream of and make it flexible and enjoyable. So all ill do is throw it out there as a recommended item from me, But i know good and well most budget people will not choose this charger. Same would go for me also had i not felt the urge to pamper myself.

23

For safety reasons, charge in a Li Po sack or charge outside. Serious!

24

I went thru this decision cycle - and almost bought the iCharger. I finally opted for the $32 (delivered) Turnigy Accucell 6. If I was into RC and wanted to control all the myriad RC type battery packs, then I would certainly have gone for a better unit. Since I am also a computer programmer, I would have gone for one of the software controlled units...perhaps even the Hyperion. But all I want to do is charge batteries around the house - ie AAA, AA, 18650, etc. And not many of those at that. I am not even sure if I will get into balance charging - I can see myself simply charging each battery one at a time. The NiMH I will simply parallel charge. For me, the Turnigy seemed good enough.

I have this feeling I might be wrong though! So I am keeping an eye out for a better unit.

I did the same thing when I first started buying 18650's. I bought a number of xxxxFire 3800mAH batteries. My goal was to get the highest mAH rating at the lowest cost. I think I got 4 of these for around $10. I now know (through this forum) that this was a bad idea. I have now bought a number of decent XTAR 2900s and will not scrimp on batteries again.

So keep up the good information! A month ago I had not even heard of hobby chargers (and now I own one).

25

Parallel charging cells doesn't matter if differences in capacity.

I've charged 1800mah, 2200mah, and 2600mah mixed, up to 12 cells at once.

Even different size cells, as long as they were the same chemistry.

Just make sure all voltages are within about 0.1-0.3V before paralleling.

Cell will only take up to its capacity.

All will end at same voltage, and guess what, THEY ARE ALL BALANCED.

Even if one or 2 cells are weak, no problem.

After resting off the charger for about an hour, I check cell voltage and you can see the weak ones, the

voltage will have dropped more than the rest of the cells.

Even series balance charging cannot correct a weak cell, It will drop same as parallel charged off the charger if weak, and series charging might take longer as the charger keeps trying to equalize the weak cell.

The only thing I series-balance is sealed packs for my RC hobby just because I can't open them and do parallel charging

26

each to there own, but i dont really agree, but do what works for you, you can still parrallel ballance charge sealed series battery packs for rc

27

I think the experts would argue the correct charging algorithms aren't applied at the right times by parallel charging as balancing charging does. Im not an expert so i wont argue it, Im just mentioning it.

28

even when i parrallel charge series li-po packs i always balance charge, there is a reason why some of of make the effort to balance charge.

im really impressed with the trust fire flames for bang for buck vs mAh, ill have to figure out how to use long veiw on my icharger as i think the results would be intresting or look impressive atlest.

the dam magnets are taking forever to get here, they must be on a slow boat from china.

29

Why not, the charger determines the charge algorithm.

Plug a 40watt lightbulb, a 60watt, a 200watt and a 10watt all into the same outlet.

They only take what is needed by each bulb.

Same principal applies to the cells.

It acts like one big cell.

30

Yes, series packs I always balance charge, Otherwise the pack could become useless because of the imbalance of the charge.

The word is PACKS. (Multiple cells in series denoting it as a pack).

That is the difference here, not loose cells.

Parallel charging packs is not the same as parallel charging cells.

31

it is the same if the voltage is not close

32

Lighthound is referring to how the parallel charging of the individual cells WITHIN a 3S lipo pack is not possible, because of the way they are wired together. He is correct.
I think becknie is referring to the parallelcarging of individual cells, but across multiple packs.
Personally im for balance charging in series for loose cells because of the high likelihood of cell voltage imbalance between cells at the start of charge, maybe more to do with the way I use my cells, and that my torches tend to be variations of single, double and triple cell torches. Cells that are permanently connected together in parallel, im happy to parallel charge, beasue its effectively just one bigger cell though.
I guess it comes down to what you tend to do with your cells.
Also regarding charging algorithm,etc… Its all the same for lithium chemistry, in principle a very simple constant current, followed by a constant voltage. Nomatter how many cells, or chemistry, the algorithm is very simple in principle. All that matters is the charge current, and the final voltage for the constant voltage phase. All hobby chargers do this very well, only the super budget chargers seem to have difficulty doing this with the more limited set of components set by the budget. And its mostly just an issue with calibration/accuracy of the final resting voltage

33

yes thats what i ment.

i series charge every thing aaa aa,s parrallel has its place, but like okwchin i have torches thats use multible cells 2 to 3 li-ions each and one single cell and i would not parrallel charge them due to the voltage diffrence.

even when i charge aa,s nimh i series charge, say two come out of my digital camera, two from my xbox 360 controller and four from a rc radio been doing that for years most premade packs for rc use are series and can only be charged in series look at the stick packs, yes the voltage of premade packs would be close, but internal resistance and even battery posistion can affect voltage.

even when parrallel charging multible series packs like 2s1p,s the balance leads are conected in parrallel the main charge discharge leads are connected in parrallel, the cells will balance say all cell 1,s will balance with cell 1,s and all cell 2,s will balance with cell 2,s, the over all voltage will balance but even my little 2s1p,s can deliver 66 amps each, so its best done if the cells are close or it can get intresting.

for the balance charge haters you dont even have to balance charge series placks, you can fast charge them, most chargers will cut out if one cell goes into over voltage (most cells have in built protection) and if you have the balance lead connected and you can see seperate voltage, but its best to balance charge if you go down this parth or atlest do it now and then.

this thread was started by me due to the lack of premade holders and charge cradles and some over complicated set ups ive see around thought it might help or inspire others, pitty this thread turned out to have more parrallel then balancing info and the thread has gone ot.

this thread is like the aussie ford and holden, gm or ford, chevy or doge trucks each person will pick out what they like for there reasons or regurgitate what they have seen else where, not many will have tryed and test each wat plus others and burnt out chargers and melted wires and seen how high the flames will get just to save a few hours charging, the people who have my hat is off to you.

if you want the best dam way to charge batteries its one by one with a 0.25 c charge at you are looking at 50+ hours constaint charging for 10 batteries or 10 days if you do one a night

there is a reason why some of use like to series charge and go the extra mile and balance series charge.

34

well i made a 6 cell balance charging lead from 2 x 3s balance leads in series with a 2 x 3s to 6s series adaptor so i can balance charge 6 x 18650,s at once, it can be broken down to make 2 x single 3s balance leads and with the 2 x 3s to 6s series adaptor i don't have to use main charge leads to the magnets.

revision 1

i cut the yellow xt60 plug off and added two 4mm bullet connectors and some heat shrink to plug straight into the charger, i brought a couple of these from hobbyking for under 3 bucks each and have used them for rc.

2 x 3s balance leads with 8 x 8 mm nickel coated rare earth magnets soldered on the end's, with a bit of heat shrink added to keep the balance wires in pairs.

all joined together, the balacnce leads simply plug into the adaptor.

all plugged into my icharger and p350 power supply, with 6 x 18650 trustfire flame batteries

individual cell voltage's

it cost around 15 bucks to make most of the cost was the magnets, ill shorten the leads i think and ill make some thing similar using a flat pack battery holder soon.

35

Love that adapter, only concern with this adapter is the sparking that occurs when connecting this many cells to the balance port, a problem with such hobby chargers and dumping 22V into the filter caps (haha)

Love the way you managed to solder onto the magnets, very neat!

36

yeah true, i make sure the charger is on every thing connected and you might get a little spark from the 6th battery when its connected but no worse then 2s or 3s ive noticed, but it should be no diffrent then connecting a 22.2c 6s lipo pack to the ballance port i hope and the way the adaptor is wired with the main charge cabes in series with the balance leads they should take some of the 22.2v dump.

the ichargers can take some abuse ive done some nasty stuff to it and it keeps going, but playing with such high voltage one should take caution, but i just halfed my balance charge time by 50% saving me around 4 hours for a slow balance charge.

ive done it this way to save using main charge leads and keep it simple so there is not a mess of working out where all the 6 balance wires goes, trying to keep it simple much easier to conect the batteries and the way the heat shrink is used with the way the magnets are soldered it make connection easy you dont realy have to think about what goes where, its only good for low c charging rates, but the next one will be a single 6s balance lead with a flat pack battery holder and the leads will be fixed no magnets as they are not the easiest thing to solder.

i feel a icharger 206b comming on, my power suply will handle it at the max 20 amp max charge and it would be good for parrallel balance charging 6 rc lipo packs at once as with this one im limeted to 10 amps max and then i can make up some 8s balance charge leads for my 18650,s as 6 is ok but 8 would be better.

37

Lol, its always like that, more more more! Hobbyking to the rescue!

Regarding the sparking, definitely more on 6S, I can see the blue light flashing through my balance connects when I connect the 6 cell batteries to the charger. The charger balance pins are changing shape due to the "welding" that occurs every time I plug one in. So I let the damage occur on the 6 cell 2 pack adapter that you have shown in the pics.

Where abouts are you in WA? Id love to see your setup some time.

38

ill send you a message

39

lol, a fair way away by perth standards.. too far for the beam of my throwiest torch to reach... But the BLF is great.

I wonder if anyone else uses these hobby chargers, and how they use them.

40

I have many LiIon chargers and often use them, but I do also use hobby chargers. I have two of these:

Where I can charge two cells in parallel.

For special size cells I have made made a clamp into a battery holder:

I always uses the hobby chargers to charge odd size batteries and when I want to charge fast, for regular charging I sometimes use the hobby charger, sometimes one of the other LiIon charges and if I need to charge many batteries I can have more than 6 chargers running.

I often use hobby charges to get a check on my LiIon cells, how much capacity they have left or when I want to discharge a cell.