protection circuit

hello, i got a trustfire 18650 battery thats faulty from new, i believe its a problem with the circuit board. is it possible to just remove the board and use it as an unprotected battery?

If that’s really the problem, then yes.

What’s the problem?

Protection is removable, but when you do you have to be careful with the positive connection of the board. This can cause shorting the batterie.

problem is it wont take a charge and it is totally drained now. i took the board out but it still will not accept a charge, so i guess it is the battery itself that is at fault…

Trustfire or (any)fire batteries already have a poor safety record & thats with the benefit of a protection circuit. Most are counterfeit.
You really don’t want anything to do with a battery thats having issues from new. Try to get a refund.

Try some protected panasonic, sanyo, etc from fasttech.

ya i only got a couple of the trustfire 18650 batts, from what ive read they seem to be some of the “better” _fire batts. i have good run times on the trustfire 26650 batts i have. but having said that i do have 6 panasonic 18650 3100mah batts comming from Intl outdoors…

“… overdischarged cell (discharged to below 3.0v under load) can be a potential fire hazard”

Zero voltage measurement does not mean the cell is safe. It is not safe, now.
Put it outside in a metal box. Recycle it, don’t trash it.
The chemicals are separated by a thin, permeable membrane. Gore-tex for example is one.
Failed cells start to grow crystals in the chemicals — slowly.
Crystals growing — over time — can eventually poke a hole in the membrane.
Then you get heat, sometimes fire.

Search for the videos of RC airplane battery fires — they push batteries hard and bang them up often, so they see this more often.

yes i will do that for sure, it measures 1.22 volts, so it is VERY discharged

It was a while ago, but last time I was buying batteries, trustfire were the go-to. I can understand if they’ve been “over-counterfeited” now, so they can’t be trusted. So, besides Panasonic and Sanyo, what batteries are recommended? I mean, you know, batteries that don’t break the bank.

they are already sending me a new one, so i figured why not give tearing it apart a try…

Dispose it. 1.22V is far from being save when it comes to LiIon cells.

No idea how far it is from being save, but it’s a long way from being safe. :slight_smile:

*slap* :D

Where did you order these defective cell?

On a somewhat related note: fasttech sells Protection Circuit boards since today:

They are the first ones I see around but I guess it’s rather hard to install them properly on existing cells, because they should be welded I think…

DX has these circuits, too. there was a thread over it here…
The DX ones were available with the metal contact for the positive side.
But perhaps these here could be used to upgrade a driver wich comes without battery monitor…I will think about that.

Also samsung. Efest seems worth looking into. Scaru’s Li-ion Safety & Shopping Guide Most of the other good names are pana,sanyo,samsung rewapped & rebranded.
Safe reliable batteries will always bee a bit more then trustfire / *fire. But you get better capacity thats consistent from one batch to another & they remain better under high amps. Some of the counterfeit junk batteries are rewrapped old cells from laptop or other batteries packs. Since its so random sometimes you’ll get cells that seems decent.

I would rather have a few of the best then a truckload of unreliable junk. Also less worry when used under high amps or charging.

LG is also great but not very common.

One of my TF 3000 stopped working, after one use.

I have made a picture from the PCB, right FET is burned.

Damn apple, they should build some retina cameras instead of displays.

Here a better picture from my cheap android phone.

Damaged one is gone.

Soldered PCB back in.

New shrink wrap

It charges again, now I have custom low current battery. I call it NOFIRE.
There is a paper spacer ring, to prevent circuit from a short. So if you build one up from zero you need this too.