Hobby Chargers

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

2 x AA battery holder

4 x AA battery holder

8 x AA battery holder

4 x AAA battery holder

4 x D cell battery holder

4 x C cell battery holder

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.

Female tamiya connector

Male tamiya connector

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.

5mm black heat shrink

5mm red heat shrink

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.

I found these 3 x 26650 battery holders and 3 x 18650 battery holders to be handy for storage and could be useful for a charging cradle or custom power supply for DIY projects. i like the fact they lock together.

I have been using them for a while now and they seam well built so far so good, crap pic,s sorry

Just saw your other post on them. How exactly do they lock on? Would they work on unprotected batteries?

They slide into place and are pretty tight and will only come out one way, the batteries do not fall out easy, you have to pry the top and bottom off the batteries together but the holders stay locked together, if that makes sense.

They will work with protected and unprotected batteries as long as all the cells are with in a couple of mm of each other. but you can not lock 26650 and 18650 battery holders together only the same type of holder can be locked together.

Ive tried them with king kong and protected trustfire 26650,s, trustfire flames 2400, solarforce 2400 V2's, NCR18650A's 3100, hi-max 2600, redilast 2600 18650 cells and they seam to all fit well.

I would use Velcro or elastic bands if your going to move around a lot with them say in a back pack in a large pocket.

Nice setup. I found a commercial solution:

i would think that 18650's are too long.

Just built this 12 volt, 3 amp power supply for use with my hobby charger. I know it's a bit under powered for most of you charging big battery packs. For my needs, balance charging a maximum of 3 18650's at 1 amp, it's more than enough power. I had all the parts in stock except the actual power supply module. I purchased that off ebay for around $7.

Installed an amp meter in the power supply. Right now I'm discharging a Panasonic 18650

Mouse over: Charging the same battery at 2.5 amps charge rate (only for a few seconds to see if

the other digit works)

Damn, that's a sweet looking charger!

Have a look at this icharger. For a few $ more it's much better quality and features (more accurate balancing, among others). It has higher discharge current that is needed for capacity testing. You may also want to read this excellent thread on serial charging with hobby chargers and the icharger specifically.

It's the same one I'm using. Although I'm not using it anywhere near it's capacity, it's balancing accuracy blows away my cheap Turnigy Accucell 6. Highly recommended!