Disclaimer: 18650 batteries can short out and catch fire. You got that! Use caution when working with and using lithium ion batteries as they are very sensitive to charging characteristics and may explode, burn, or cause a fire if misused or mishandled. Always charge in or on a fire-proof surface. Never leave batteries charging unattended.
Charge only with a smart charger designed for this specific type of lithium ion battery.
OK so some regulators got into the mix and endorsed a solution to a problem that doesn’t really cover much but we will look at that first
PRBA –The Rechargeable Battery Association applauds the Safety Warning issued today by the U.S. Consumer Product Safety Commission (CPSC) regarding the safe use of 18650 lithium ion battery cells. PRBA’s policy on the use of these and other cylindrical lithium ion battery cells explains how manufacturers of these products never intended them to be sold to consumers as loose, replaceable power sources without the necessary safety protection features.
Ok Great, so don’t buy loose 18650 batteries because they don’t have electronic circuitry to protect from overheat, overcharge and short circuit. Yeah but they don’t explain the battery and the manufacturing process and manufacture certification process.
Why did this come up, because I purchased a head lamp from Amazon and the batteries had no labeling, no identification and no traceability. They had caps like a battery that has electronic protection but how could you know?
Good Bet these are not protected just on cost. Quality protected ones are around 10 bucks
Button Top–Flat Top Electronics ?
There are button tops with protection, and without. There are flat tops with protection, and without. The button, or lack thereof, does not indicate whether a cell is protected. There is no difference in risk between button top and flat top cells, all else equal. The main thing is to make sure the cell fits well and makes good contact – some lights work better with one type or the other.
Button tops are just that, a button or nipple looking thing on the end of the battery.
Protected and non protected Li-ion has nothing to do with the physical + end contact. Although you may find a trend that more protected batteries are button top and more non protected are flats
Going through my inventory of misc recovered batteries It became evident that alot had no identification and even removing the blue plastic cover revealed no traceability
Constantly topping off charge for hours, days and weeks is abuse and will only result in a reduction of cell capacity, current, and ability to hold charge. Over-discharged cells below 2.5V for Li-ion (which with LiCo chemistry can cause them to explode or catch on fire if charging is subsequently attempted).
Do not mix and match old and new, used and unused batteries.
This is a comparison of protected and unprotected by price
Samsung 25R 18650 2500mAh 20A Battery
A great follow up read is protective circuits
- MISUSING OR MISHANDLING LITHIUM ION BATTERIES CAN POSE A SERIOUS RISK OF PERSONAL INJURY, PROPERTY DAMAGE, OR DEATH
- BATTERIES MAY EXPLODE, BURN, OR CAUSE A FIRE IF MISUSED OR MISHANDLED
- ONLY USE WITH PROPER CIRCUITRY IN A PROTECTED BATTERY PACK
- ONLY USE WITHIN MANUFACTURER LISTED SPECIFICATIONS
- DO NOT STORE LOOSE BATTERY IN A POCKET, PURSE ETC. – ALWAYS USE A PROTECTIVE CASE OR BOX
- KEEP AWAY from metal objects to prevent short circuiting
- DO NOT short circuit
- DO NOT use if wrapper or insulator is damaged or torn
- DO NOT use if damaged in any way
- DO NOT overcharge or over-discharge
- DO NOT modify, disassemble, puncture, cut, crush, or incinerate
- DO NOT expose to liquids or high temperatures
- DO NOT solder, spot weld only
- User must be familiar with handling lithium ion batteries before purchase
- Usage of batteries is AT YOUR OWN RISK
- ALWAYS charge in or on a fire-proof surface and never leave charging batteries unattended