Is my charging setup safe?

Hi guys!

I am still quite new to 18650s, so I hope some “expert” might better enlighten me on safe charging practices for lithium cells

What I am now doing is:

  1. I’ve gotten this rather big 11 gallon steel bin from IKEA.
  2. In this bin I put my charging setup, a Xtar SP2. A small copper shim with a K-type thermocouple bead soldered onto it is placed across the bodies of the cells during charging, and the shim is held in place using a small elastic band
  3. The thermocouple is then hooked up to a Extech 421509 data acquisition device with alarms set to go off when the shim reaches 40 degrees.

So far, it seems to be working fairly decently. If both cells get warm during charging, I catch it fairly early when they are both around 40 degrees each. If only a single cell warms up during charging, the buzzer will still go off, albeit somewhat later when the cells are close to 60 degrees. But either way, I do get some audible alerts warning me of hot cells.

My big concern though is: is temperature the only thing that I ought to be monitoring? Is it possible for a cell to “vent with flames” when it is completely cool to the touch at 35 degrees?

Looks like overkill to me. I mean, really, I wouldn’t trust that 11 gallon drum - IKEA?? You can’t be serious :wink:

Id call that “creativity” at its finest. Its all about having fun and enjoying the hobby. Lets face it… gadgets are fun. You can also use that thermocouple to gain precise temperature readings of components (such as heatsinks and emitter stars) with great precision… something IR devices dont do as well in environments containing several components with different temperatures in close proximity.

I charge my questionable cells on a long extension cord in the middle of my back yard. No foreworks yet… but Ive gotten rid of almost all of my cells labeled “made in China”.

It is made of “real” made in China steel :slight_smile:

But if the steel strength rating is the same as Chinese Lumens, NO PROBLEM ............


Be Careful out there !!!!

I charge me on the floor next to me while I watch TV. I did make a slate box to charge them in but never use it. I don’t charge crap cells though.

I recommend putting a range hood that vents outside over the top of the can if you have the money. Another good thing to protect from venting is get a sheet of aerogel, and surround the can with that! BTW, I’m totally kidding, I myself only charge when I’m home. And I just put it on top of my computer tower if I’m in my room. Or i’ll put it on the carpet in the living room if I’m there. But sometimes If I’m feeling paranoid, I’ll put the charger w/cell in a electrical box or a metal toolbox I made in 7th. For all the stuff you bought, it’s better just to spend a few bucks more and get a good cell. I would never ever ever buy any of those ultrafire type cells (they have fire in the name….). I stick to at least tenergy cells, and soon I’ll get some panasonic 3100’s, probably orbtronic or some other brand. Maybe you are just a cautious person, but mom would do something like this and she has GAD.

Cool set up! I just set mine on a stainless cookie sheet & only charge when I’m in the room with it. I do set a little timer to go off every 30 minutes that will remind me that I am charging battery in case I get side tracked :open_mouth: