Yeah my button top MNKE 3500mAh 26650’s have non-ferrous button tops. I have to use a clip on the positive terminal.
I think one of the 99 cent (when on sale) 6” plastic clamps should work without much effort. The kind you squeeze a grip to move along a bar, with a couple plastic pads on the arms. Rig a set of leads to the pads and ready to roll.
Yup, that’s what HKJ illustrated in one his tutorials. It will work well with one cell. More difficult with two or three though.
I just buy the cheap battery holders from fastteck and make up purpose made serial cradles for my different configurations. It allows me to charge in series with the battery balancer so you can charge multiple batteries in the same sime as single cells. for small single cells i typically use the magnets
here are a couple that i made:
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I had such selfmade cradles first.
These cradles are to short for the 70mm protected cells, also the spring material is bad and the whole thing gets a bit “deformed” while soldering, as the plastic tends to melt easily.
But you can get the bare cases of usbpowerbanks from fasttech too, I have a two cell case which has huge springs which could be shortened…
Also it isn’t possible to detect the single cell capacity when discharged in multicell configuration. The only good thing is that you can charge the cells really fast with decent current.
I still wondering why no manufacturer makes a i6 style cradle(maybe even 5mm longer) with bananaplugs and balancer cable for hobby chargers ….?
You could buy these universal chargers at harbor freight for pretty cheap. Or even online.
I turned this:
Into this:
Build thread here: https://budgetlightforum.com/t/-/7791#node-9163
Too short these standard battery charger are, my padawan…
Also it would be perfect if there were more bananaplugs on it for every count of cell e.g. If you only want to charge 2 cells…
There are balance wires, you can charge 1 up to 4 really. The banana plugs just provide the power.
You'll need conductive dummy cells in the remaining slots when charging less than 4 cells. Otherwise there's OC.
Don't know what the charger thinks about shorted balance connectors though.
Yes, that's right about needing dummy cells, I did have a problem with the balance connectors at first, but I managed to fix that by making balance wires interchangeable using screw type connectors. It's a little trouble, but it works.
Is there a reason you can’t connect all the balance harnesses in parallel? You’d still need multiple connectors for either the -ve or +ve power connector of course.
Hmm, I don't really see how it would be able to work in parallel using balance plugs. It would work without using balance plugs, but then again it isn't a good idea to charge in parallel due to differences in internal resistances in each cell. Unless, they have exactly the same internal resistance, one cell will charge at a higher amperage due to this and charge faster while the other will charge slower. It's potentially dangerous because of overcharging.
Charging in series with balance plugs allows cells to charge evenly because the balance plugs will bleed off the extra voltage/current.
You need a bananaplug on every cell to charge all kinds of counts. That’s what I said. Please correct me if you can charge with balance plug onlys.
You can connect all slots with one big balancing connector, this makes no differnts as the 2s balance connector of your charger is the same as the first two cells of the 4s slot(these are electrical conducted)
But then you need the power cable on every battery, this could be done like above just two bananaplugs more, so no big trouble and easy to use.
I am also not sure what happens if you charge uneven discharged batteries, I guess this will stretch the
But the main problem for an universal cradle is the cradle as it has to be 80mm long and 35mm wide or so to fit all kinds of batteries.
If you only build a customs cradle to charge one special battery set very fast and good the above one works perfect, but I would like to have a universal cradle. These exist for normal battery sizes(around 60mm ±) but I haven’t seen some for cylindrical cells.
Yeah the whole point of this exercise for me was to avoid balance charging as I may not be charging the same cells at the same charge. This is why I bought a 4 channel hobby charger. I need to quit being lazy and gut/modify the chargers that Werner recommended. I have 4 of the chargers, it just takes me a while to build up the motivation to do things lol
This is what I meant. 
@photon1k:Oh wow, I'm confused lol. I don't know how the charger would read that, it might give you a voltage error.
@Werner: Hmm, I think your talking about individually charging each cell in each charging bay. My charger mod is wired in series like this:
It can charge batteries as big as the 32650s. I don't normally use protected cells, but if needed the negative contact plate can be trimmed to fit longer cells due to protection circuits.
Heh! It looks unorthodox I admit, but your diagram is the same as my 4S option. It’s just that there are some extra balancing wires in parallel with the 4S wires. If you check your charger you will likely find that the balance ports are wired in parallel. You can use a DMM in continuity mode to verify this.
Edit: To clarify, for example, pin 2 of the 2S port is connected to pin2 on the 3S, 4S, 5S and 6S ports.
Photon that is what I meant too, so you only need one 4s balance plug.
And of course the individual bananaplugs, which you have in your drawing too…
Yes, the drawing shows two, three or four-cell options. It can be constructed to balance charge from 2 to 8 cells. If your max cells = 6 then use a 6S harness plus a negative connector for each cell. If you’re only charging 4 cells that day, plug the -ve power wire into the fourth cell.
Is there a reason not to charge multiples in parallel? Is it just that they all have to start out around the same voltage before charging, vs. charging in series with the balance connector which can deal with cells of a wider range of voltage?
I have enough 18650s that I wait until I have 6-8 that need charging, and sort them into groups with voltages within a range of about .1v, put them in the parallel box and let them equalize for a few minutes, then charge.