If you don’t have a hobby charger, individually charging the battery pairs is the way to go.
Here’s what I’m currently doing:
I hooked up one of the pairs with magnets and I’m charging it up to 4.20V. After that’s finished, I’m going to switch to the other pair and charge it up to 4.20V.
If you do have a hobby charger, you can take advantage of the green rectangular PCB and solder some leads to them and connecting it to the balancing port of the hobby charger.
I was hesitant about cutting open the black shrink wrap, but after Default Username said that they were not balanced, it was a no brainer.
That’s correct. The one with the lower capacity will always have a lower voltage after a discharge cycle, and if charged without balancing, the one with the higher capacity will be overcharged beyond 4.20V. I doubt these would explode as in a flashlight, but venting wouldn’t be very present either.
I’m glad I could help ryansoh3. Interestingly, the circuit board on your pack looks quite a bit different than the one present on my pack, despite them looking quite similar on the outside. Here’s a picture of what I found inside mine. The two 8-leg chips on top are marked 8205 24C1G, and the 6-leg chip is marked 3W17. The “balance” lead was connected to COM, B+ and B- to battery, and P+ and P- to output.
Some folks on the MTBR site converted their packs to removable batteries. I had planned to do the same so I could firstly, use better cells, secondly, be able to charge the cells individually.
That might be explained by the internal charge leakage being higher when the cell is discharged than when it is charged, or by the lower capacity cell also having more leakage. If they were always equally efficient, in terms of the charge out equaling the charge in, they would stay in balance when charged and discharged in series, even though they had different capacity.
So, if I’m reading correctly, if I have the version with the board on the top I’m OK? Assuming it is wired the same. Or not?
Edit: oh, I see the Kaidoman one has the “bag” too.
I'm planning on using the DX Pannovo case as well (it's just taking DX FOREVER to ship my order while they wait on an item to come in stock). I was also tinkering with other DIY ideas to be able to use my own cells and pull them to charge them individually.
Question - how safe/unsafe is it to use 4 high quality BUT unprotected 18650's in a case like the Pannovo?
Does my post#62 here help you: https://budgetlightforum.com/t/-/29016?page=1#comment-845487 (sorry I can't create a link from my phone anymore it seems) . I've not actually connected mine to a hobby charger yet though but I can measure each banks voltage across the balance plug with a meter.
watch out for packs like that with fake,dummy cells and widely differing capacity on the 2 “good” cells.
forget these cheap and nasty packs and just buy the reloadable pack mentioned.i know of 2 riders who had this type of pack blow up while charging.
now they run 4 18650b and charge the cells in an all-80 8 bay.
risk went to near zero.performance doubled!
Problem is that case above to use your own cells is no longer available. The new SolarStorm 4 cell case is crippled with protection circuitry that doesn't work correctly and parasitic drain (&usb power that many don't want). The fix for the SS case is posted in its review thread over at MTBR, but I didn't find it easy to do. Those cases also stink for any light drawing over about 2.5A.
Ledoman has KD producing custom packs with Panasonic cells and seeing good results. GearBest seems to be selling some of the same ones but I'd support KD on these.