Why would you charge 18650s @ 3.7 volts in series and 4.2 volts in parallel?
you would not, but to get a hobby charger to charge a 3.7 volt li-ion like a 18650 with a fully charged voltage of 4.2 volt you have to use li-po mode or the hobby charger will only charge as a 3 volt li-ion.
the 18650,s are sold as 3.7 volt batteries but the fully charged voltage is 4.2v, its the same as li-po,s the hobbly charger will register 6 x 18650 in series as a single pack 22.2 volt 6s li-po, they have a fully charged voltage of 25.2 volt the same as 6 x 18650,s.
its the same as a 7.4v 2s lipo or 2 x 18650,s in series they register as 7.4 volt but they fully charge to 8.4 volt
its the same as a 11.1v 3s lipo or 3 x 18650,s in series they register as 11.1 volt but they fully charge to 12.6 volt
this goes one and one till you hit the maxium cells your charger can handle.
Just charge one battery at a time and you avoid all the complications. That's what I use my Turnigy to do. Then the only thing I adjust is the current, depending on the capacity of the battery I'm charging. I do NiMH's on chargers made for AA/AAA (Sony and Powerex), so I leave the Turnigy on the LiPo setting (3.7V, charges to 4.2V). Sometimes I'll do a storage charge or a discharge test. It's pretty easy.
5,5mm jack.
I have almost identical power supply, as in this auction: http://www.ebay.com/itm/72W-12V-6A-AC-Power-Supply-Adapter-Battery-Charger-Cord-Laptops-LCD-EU-Plug-/190584501174?pt=Laptop_Adapters_Chargers&hash=item2c5fb8b3b6#ht_3531wt_1350
It was cheap but has been working well.
Most of this type of hobby charger have an acceptable range of input voltage - 10 to 18 volts seems common. It doesn't have to be 12v. However, even an additional 0.5v will cause the charger to register that the voltage input is too high, and it won't allow you to proceed with any functions. Unfortunately, this means that your 18.5v power supply probably wouldn't be suitable (even if you had the correct plug).
As far as i have understood in this thread, the typical and most recommendable way to charge several cells at a time is to connect all cells in series and use balance leads: this way the cells end up being connected to both the standard output (+, -) and the balance port. Even with a cradle (battery holder) you end up with several wires.
And then it is said, that NiMH cant be used for such a balance charge setup -- so we would charge them in series (i.e. same as in a balance charge setup) but without any connections to the balance port. Then again, this primitive setup is only recommended for NiMH's with identical charge levels (e.g. 3x Eneloop AA: 58%, 62%, 60%).
But what about Eneloops which have varying discharge states, e.g. 3x Eneloop AA: 30%, 50%, 70%?
And the least recommendable method be charging a set of cells (e.g. 4x 18650, or 4x Eneloop) in parallel .. because in a similar fashion, all 4 cells should have the same voltage (e.g. 1.41V, 1.41V, 1.43V, 1.42V). The "advantage" of parallel charging would be: you cant use the balance lead or the balance port, and thus you end up with 2 wires only: + and - for the standard output (+, -).
Most obviously, the easiest way to use a hobby charger for recharging our typical flashlight cells is by charging a single cell only (e.g. 1x Eneloop, or 1x 14500). We could use either the standard output (+, -) or the 2-pin balance port. So people with a lot of time who dont mind charging one cell after the other (protected or not, doesnt matter here! 1x Protected 14500, then 1x Protected 10440, then 1x Protected 18650) can profit from their hobby chargers.
Last but not least, the manual would suggest not to use the balance charge method with Protected Li-Ion's (e.g. 3x Protected 14500's in series, with balance leads to the balance port) whereas the users still do exactly this, ha.
Li-Ion safety is another issue and the standard budget hobby charger isnt shipped with a temperature sensor and the least expensive premium hobby charger with update-able firmware costs 79.99$ + shipping and comes without power supply.
The least expensive budget hobby charger be the genuine Imax B6, which too comes without power supply -- it is pretty much identical to the "discontinued" Turnigy Accucell 6. (the fake Imax B6 comes with a power supply. In all three cases, the package doesnt include a temperature probe/sensor.)
All correct so far?, or any further explanations or comments?
here is video tutorial which explains that parallel charging is more recommended than series charging. i think it's time to give up :D
So where can i buy the Maha C-9000?? LMAO
Where are you seeing the Accucell 6 being discontinued? Hobbyking shows it being out of stock, but that doesn't mean it won't be back in stock at some point. They were selling them as recently as a month ago.
For charging AA cells, I don't mess with the hobby charger. I have a C9000 though. The Sony Cycle Energy is a good cheap choice. I think there is an inexpensive Panasonic that charges each cell individually as well.
Not sure what the answer is for charging multiple li-ion cells, so I do one at a time. A lot of battery packs (which is what hobby chargers are really meant for) don't have balance connectors, so I think charging in series is okay if they were discharged together as well. And I have heard li-ions do well in parallel and kind of self balance.
From the above posted video (and its video series) it becomes apparent that the question
multiple Lipo cell charging in series vs. multiple Lipo cell charging in parallel
is still a major point of discussion on forums among experts and no definite/clear general recommendation can be given. In both cases, though, the foremost prerequisite appears to be that the cells should be as identical as possible incl. voltage/discharge level.
In fact, when we look at laptop cell packs (e.g. 6x Samsung 18650), their 6 cells are connected in a mixed combination (2 in parallel, then in series: 2-2-2) for various technical reasons (stabilization, ..). You could do your maths to calculate the adequate charger settings (Amperage, Voltage) .. but balance chargers (Imax B6, etc.) arent meant to recharge such 2-2-2 sets either, although i am certain that you can do it without problems as long as you connect them properly to your balance board.
But let's be honest, balance charging a 2-2-2 set with an Imax B6 and a balance board is quite challenging! It's more straight-forward to check each cell individually and recharge it one after the other and finally put them back together.
I am well getting now, after having watched the youtube videos (and none of them treat AA, AAA or Eneloops or our round-shaped Li-Ions!!), that those fantastic hobby chargers (iCharger 106B+, iCharger ...) are *absolutely* not meant to recharge our round-shaped Li-Ions.
Not even pre-made battery holders (cradles) for balance charging round-shaped Li-Ions exist (HobbyKing, ..), this says it all. And in the aforementioned case, if you have totally unequally leveled multiple cells (e.g. 15%, 50%, 85%), then it's not recommended to do any balance charge anyway lol (results in a waste of time, etc.).
What the flashaholic rather needs is *individually* controlled battery compartments, i.e. multi-output chargers.
Hobby chargers are single-output chargers (plus balance port) meant to recharge battery packs (which are multi-celled and come with their own balance mini plug).
yeah. again the smart al*ck me. haha
I bought the same one from here for $20 and a power supply for $6.
I only use it for my LiPo batterys for my RC cars.
I bought a normal $10 charger for my 18650 battries so i can just pop them in and the green lights come on when they are full. I cant be bothered with fiddly battery clips and holders and going through the settings every time.
My usual setup:
Charging a car battery:
maybe one of the best combinations is having the Intellicharge i4 (25$) for fiddle-free charges of both NiMH and round Li-Ion's, and the hobby charger (20$) for analyzing single cells if needed/wanted. Both handle our NiMH and Li-Ion's. The main advantage of the hobby charger: it has a display; the main advantage of the Intellicharge i4: it has integrated battery holders (cradles).
The perfect charger for our needs would be something like a Maha C-9000 with additional Li-Ion support: cradles, display, multi-chemistry --- perfect!
Its been asked in this thread how to charge nimh batteries i use these
I put tamiya rc connectors on the end of the battery holders and make up one charge lead with the opposite plug from the charger, the battery holders ive posted are all in series but thats how the hobby chargers charge nimh, chargers like the Ichargers and so forth can do form charging that can help to balance out series nimh battery packs.
thanks for the links! benckie, you want to share photos and wiring diagram of your setup? ;)
Well basicly the battery holder's come wired like this.
I add a large female tamiya connector to the battery holder leads and i bit of 3mm heat shrink to neaten things up a bit.
To be technically correct the positive wire goes on the left when the large single tab of the female connect is facing down and the two small separate tab's are facing up and the connector is facing away from you so the side the terminals slide into is facing you.
You will understand what i mean if you had a female tamiya connector in front of you, but as long as the positive and negitive wire match from the battery holder to the main charge cable it is all good.
Then i use 4 mm male banana plugs as this will fit all hobby chargers and 4 mm (16 awg) black and red silicone wire and 5 mm heat shrink and make a main charge lead like the one in the bottom of this picture below.
You don't have to use tamiya connectors you can use any plug of your choice or plug it directly into the charger, I do it this way cause i have many things that plug into that tamiya main charge lead so i can swap back and forward and i pick large tamiya connectors cause they are cheap, very common and Ive been using them since the 1990's, now they need a special crimping tool, Ive never brought one, i just fold and squish the pin,s over the wire with long nose pliers and then solder them its much stronger then crimping alone IMO.
Or you can buy a premade tamiya main charge lead but you will still have to add female tamiya connectors to the battery holders.
4mm banana connectors these are actualy bullet connectors but i like them better over the banana connectors as the wire is held in with solder so a screw thats easly strips but heat shrink is needed.
All items can be found on hobby king (apart from the battery holders) or ebay for dirt cheap you can make a few battery holders for less then a few bucks each and have parts left over to make up more charging leads for your hobby charger.
Ive posted all thats needed, the battery holders are only cheap and the wire they come with is only good for 4 amps maybe 5 amps top,s, Ive noticed no excess heat with 4 amp charges on my icharger, this should be fine and since they are in series the charge rate is the same as if you are doing a single battery its just the voltage increases automicly with the charger and the time of the charge is shorter.
I perfer to slow charge as many batteries as i can in a group, then fast charge them one at a time, slow charging in a group oftern works out faster then fast charging one by one and the batteries will last longer, take more mAh and the internal resistance will stay lower for longer.
Now for people using 10 000 mAh D cells 4 to 5 amp max might not be good enough, my D cells are only 5000 mAh and i only charge them at 0.125 c to 0.5 c but for AA, AAA and C cell,s it should be more then enough i hope this helps.
Thanks benckie for all! great instructive contribution :)
looks a little complicated but such posts help to get started.
H)
I have to make another 4 X D cell holder soon ill try to remember to take some pictures as im doing it, but its fairly straight forward.
HobbyKing has pretty good selection of plugs/connectors. Personally, I like the XT60 connectors (the yellow connectors shown in benckie's setup), overkill for battery charging but they are easy to solder and work on. I use them on my RC.
EC2, EC5, Traxxas (black connectors shown in benckie's setup) and Deans are pretty good too.
They are all good connectors, you dont see deans around to much now, hpi still use them on the hpi vorza, but most battery sellers are not aloud to sell batteries with deans any more.
I brought a few bags of the clone traxxas connectors and i like them a really tight snug fit easy to solder cheap ive been using them at around 40 amps no problem they should be good for more.
For my next project im going to use 6mm bullet connectors on the ESC and batteries run in parralell as they will need to give around 120 amp, ill reverse the connectors so in a rush i know i will not be able to connect them.
But for the thin wire used in these battery holders ive found the xt60, traxxas and dean connectors to be to tight for the wire thats used its to easy to break the wire while trying to remove the plugs to swap out battery holders or change the charging set up and they are way over kill for charging nimh batteries hence why i use the tamiya connectors.
I made some more of these today, crimped and soldered plugs on them and added a bit of heat shrink to neaten up the wires. Top 4 x D cell battery holder wired in series for charging brought from eBay. Bottom 3 x 18650 battery holder wired in series for testing 12.6 volt brought from DX.
