4p 18650 at 1a.
assembled with bubblegum & baling wire ca glue and zip kicker.
dont reverse any cells or the thin wires become fuses(intentional).
also kills tp4056.
i coated the board with ca to protect it.
the holder is an ebay cheapie from china that i prefer over the more expensive mpd at digikey.
dont have to bend the contacts to prevent wrapper snagging.
not bad for $1.35 each SHIPPED FROM CHINA.
i busted the partitions out to allow 26650 to fit too.
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Cool idea. Where did you get your “good” TP4056 from? i’m seeing many of them now from cheap sellers with fake chips on them.
Well I recently bought a bunch from a US seller; I was unaware there were fakes. How am I supposed to know if they’re good?
There is a topic mentioning the fake issue here on BLF somewhere. I think the fake TP chips had different or no numbers.
I believe most chips from ebay are fake… but they work sort of ok with simulated CC/CV. I made a dual bay version but without a good 18650 holder it is not very convenient.
the ones i got came from icstation.
they seem to work fine and have accurate cv.
only issue was a few had the usb crooked.i just heat it with the air pen and nudge it into place.
Do you have a link for the holders?
I had those with protection and those with springs, but I never had one of these.
Thanks for the link. This looks better than the spring type that are impossible to remove the batteries from….
I hear what you say about being impossible to remove. What I've done to fix this problem is drilled a hole the diameter of a pencil about 20mm in from the negative end of each bay and push the batteries out with the eraser end of a pencil.
A bit dangerous this way as the individual slots are not isolated….putting batteries at different charge levels into a circuit could cause issues as the higher charge batteries will push current into the lower charged batteries…too great a difference and the current flow could get dangerous.
I did the same thing…but was educated on the dangers of mix and match batteries in a parallel charger like that
Be safe…but still a very cool idea
Boards are cheap enough…get multiple single slotters and charge boards…safer that way
yes the non techie folks can get into a bunch of trouble fast with this.as for differing charge states i tried mixing dead and full cells and the high current leveled out fast.
measured 5a and that settled down to 2a in 30 sec.
nothing i would worry about.any reversed cell in the holder is trouble.that where the thin fuse wires come in.would suck to have a hard short where nothing gives!