10 Pcs 5V Micro USB 1A 18650 TP4056 Lithium Battery Charging Board with Protection Charger Module

Seems delicate, but works well to charge the batteries i scrapped out of bad tool battery packs!

Devices are great and work well with my 18650 china batteries. However, no matter how you solder your pins this device will not line up correctly to fit into a breadboard.

Work well for small battery projects. Charges single cells only. Does not like to have two boards operated in parallel to double amp throughput.However used on a couple flashlight mods, and such. Very robust; but to keep them from cooking themselves, limit battery size to 5000-6000mAh.I had a 20AH 3.7v bank, that was low; went from 3.2v to 3.65 before they completely failed to charge. Tried to cool with a small heat-sink two new boards, and same result. Roasted. Luckily they were inexpensive, so no loss with experimentation.

I picked these up to salvage LiPos from disposable e-cigarettes and they work great.

Wired it up, 1 red and 1 flashing blue LEDs come on but battery voltage stays the same. There's a garbled note in the product description warning of some issues starting up first time but I and another engineer friend can't figure out the note.Using a 2A $20 Motorola fast charger USB source.Note doesn't make sense:"Note: The first time you access the battery, it may no voltage between the output OUT + and OUT-, then access 5V voltage charge your energy can activate the protection circuit, and the battery from the B + B-, then draw a line on the short open also need recharged to activate the protection circuit. Note that the charger must be able to output 1A or more to do when using a mobile phone charger input, or may not charge+ MICRO USB female and next - pads for the power input, access 5V. B + positive then the lithium battery, B- then negative lithium batteries. OUT + and OUT- connected to the load, such as positive and negative electrodes connected mobile booster plate or other load."Gonna have to buy another one I guess.Disappointing.Edit 1 tried another unit and it worked.Old one still NG. Power it up, red LED is solid, Blue LED fast flashes. All solder is good, no cold or shorted.

Compact size, easy to read labels and good price, not sure what else you could ask for. This was to feed an ESP32 board with a motion sensor to allow it to run off of batter while the power was off or interrupted. Soldered 5v in, battery and power out wires with no issue. Battery output leads at first check were around 4v, then 4.1, then 4.5, then 4.2v checked every half hour or so and then kept steady at 4.2v. I'll update if anything else comes up but unless it has a short life this is a good one.

They work great and do what you’d expect .. there are no instructions with them so do some research or you will be lost if you have no experience with soldering them into stuff .. but don’t let that deter you

No problems with these. I've been using them to reconfigure products I have that use other types of batteries with a #18650 Lithium-Ions for extended battery life and to standardize what style of battery everything I have uses. They cut off batteries before they are overtrained. Easy to use. Not too big. Would recommend them highly.