Charge/Discharge Protective Circuit Board for Rechargeable Li-Ion Batteries (17.4mm*1.9mm)

Pros: Few items that I bought from DX exceed my expectation. This one superior. Here are the technical: Charging cut off 4.25V, Discharging cut off @4A, 2.37V, cut off recove to 3.2V. PCB votlage drops @4A = 105mV, @.75A =21MV, measured 1/2 inch from PCB. Excellent.

Cons: My intention is to use it on cordless hand-drill. It cuts off. The starting current is estimated to be at least 15A, obviously it protects. There is a space for another MOS switches, and I will add one to boost the current to 15A. But 'm afraid still is not enought

Other: There are 7.2Volt version for 2 cess system, I have asked DX to sell them. I am not hopeful because I many suggestion that did not materialized.

Pros: works. cuts off when voltage is to low or high. havent tested the correct voltage yet. fits perfectly on my used laptop batteries. they are 18650. makes my old laptop batteries protected in single battery applications. the metal bands have the correct length. no need for adjustment

Cons: the metal bands are not tinned. so you need a lot of heat in your solder iron. mine have that so not that big of a problem. it come with no ring to make it straight.

Other: works great. better to be safe than sorry (and an exploded flashlight in your hand)

Pros: + Reasonable price (but could be cheaper).
+ Fits 18650 batteries perfectly.

Cons: - Could be cheaper.
- The cutoff voltage is 2.75 V, not 3.7 V.
- Requires soldering skills.
- After connecting to the battery this battery gives 0 volts, to make it work put battery into the charger for 20-40 seconds.
- Protected battery becomes longer - be sure that it will fit your device.

Other: If you have unprotected Li-Ion batteries I recommend you to protect them.

Pros: - Seems decent priced - Small form factored - Perfect fit

Cons: - Needs soldering to Li-ion batteries which is considering dangerous to the batteries, however, if the soldering time is keept short, it shouldn't be a problem. (Don't resolder until the battery has had time to cool off)

Other: This item turned a flashlight battery for into a cheap investment instead of a rather expensive matter. Bought three to test, more might be needed!

Pros: Simple and effective PCB. I use it with an old-cordless Screwdriver (KC9036 from Black & Decker) which was working with a NiCd destroyed battery. Two 18650 cells and this circuit and returned to live!! No more discharged screwdriver when you need it!

Cons: It would be nice DX gives an adaptor ring or something to tight de PCB to the battery body. Its installation would be easier and the result better, with a paralel PCB to a parallel battery. An easy fixable issue though. No more cons.

Other: The PCB works pretty well. i think I'm using it in its limits.

Pros: Cheap (considering free shipping with only one piece of it) Small, compact form (fits 18650 cell)

Cons: Cutoff voltages could be more...considerate. I'm afraid the battery taken to these voltages will die fast - but IT IS ONLY PROTECTION - not charger. It is supposed to be the last protection against fire, explosion... when normal charger breaks or when something short-circuit the cell

Other: Cutoff voltages can be seen in my video. Good as protection circuit - not charger!!!

Pros: Very cheap
Well built
Long enough tabs
Fast delivery
Seems to work fine.
I bought these to replace a stock protection circuit i had on a blue trustfire 18650. I had stripped out the trustfire's circuit and transferred it to my diy parallel 8 cell pack.
It couldnt run my voltage booster circuit connected to a 6W 12V fan, because the initial current surge kept tripping the protection circuit. It was too sensitive.
Swapped to this chip and it could handle the surge current without tripping. Great.

Cons: No cons to speak of. If it cant handle short circuits as some DXers have tested, at least the FETS burn out first, instead of your battery pack exploding. Hopefully this is the worst case scenario that could happen.

Other: Get it, its cheap. I soldered them to JST cables i bought from DX, heatshrunk the tabs and wires to protect them from short circuiting. Now i have a detachable protection circuit to use on my unprotected battery packs.

Pros: Really cheap protection circuit, SAVED MY LIFE A FEW TIMES and prevented the battery from blowing up when I plugged it into a cheap china made faulty charger. This is a must get for all 18650 batteries.

Cons: Makes the battery longer than the standard 18650 size, may not fit for some torches/devices/battery holders designed for 18650's.

Other: A MUST for all 18650 batteries! You NEVER KNOW when you'll make a mistake, this thing will save your life!

Pros: This protection circuit fits on the negative (-) side of standard 18650 lithium cells found in laptop batteries. It actually has 3 wires in the shape of thin stripes. The positive wire is the long one. It only taps the positive terminal of the battery. The shorter negative lead is connected to the battery's can and it is connected internally to MOSFETs that can break the circuit if certain conditions are met. Even though it shouldn't be used like that, it is entirely possible to use this circuit to stop the charging when the voltage reaches its maximum value.

Cons: It is incompatible with batteries that contain more cells in series. When first installed, the circuit is open by the protection and one has to connect the in- and out-negative leads briefly to kick-start the battery. Otherwise, one may connect the charger. When in the OFF state, the circuit will never come on by itself, an external voltage must be applied.

Other: This is a must-have spare part for your drawer.

Pros: the most important thing is that you don't have to build it yourself.after using it intensively i can tell that it certainly saves your liion from bursting into pieces and killing everybody around.it protects from allmost every error in charging and using the battery.however it is important to know what you do

Cons: values for the voltage cut are pretty much not equal and exact. short circuit protection is very aggresive and disconects faster than the 10Amps specified.

Other: i bought and i will buy more. you can buy with confidence this very cheap but very usefull item