charging 18650 batteries?

Hello I tried doing a search but failed to find my answer.

I just bought an 800mw 445. Which came with one trustfire 18650 , a charger and goggles.

My question is how long should the 18650 charge? I don't want it exploding

Take the battery out when it gets to 4.2V. My charger takes ~4hrs to fully charge an 18650. It depends on the battery capacity and the charge rate

Do not forget to monitor charging in process. It is important that you take battery out once green light is on (LED is built-in usually).

Why?

Cheaper chargers usually continue to charge battery even after you see green light.Overcharging 18650 battery could become serious safety hazard.

Also monitor your battery for temperature. Do not charge it on a carpet or anything that can catch a fire.

These are important things when you dealing with Li-ion batteries.

Especially 18650 batteries made by various XXXXfire.


Enjoy

Brenner said:

Cheaper chargers usually continue to charge battery even after you see green light.

Click to expand...

Is that a circulating rumor, or is there proof somewhere?

Cyparagon said:

Is that a circulating rumor, or is there proof somewhere?

Click to expand...

Your input would be very valuable for a new member of this community.

I am sure you have huge experience with charging 18650.

I will always provide valuable info to somebody who maybe do not know.

Hopefully will help those members who do read these threads, looking for right info as well.

My $9 shipped from DX trustfire TR-001 charges right to 4.2V. I have left batteries on it overnight, by accident, and they were right at 4.2V and cool to the touch. However, I'm always in close proximity when I charge my cheap batteries with my cheap charger and I try to take the batteries off right when the light turns green because it's just easier to be safe than on fire, or exploded, or any of the other horror stories I've heard.

Drew said:

My $9 shipped from DX trustfire TR-001 charges right to 4.2V. I have left batteries on it overnight, by accident, and they were right at 4.2V and cool to the touch. However, I'm always in close proximity when I charge my cheap batteries with my cheap charger and I try to take the batteries off right when the light turns green because it's just easier to be safe than on fire, or exploded, or any of the other horror stories I've heard.

Click to expand...

Excellent point, and very valuable info that you've presented to our community.

I guess ill have to check the batteries voltage with a multimeter? (I think that's what its called)

Also I saw on the battery not to swap polarity....which made me think, does the positive side of the battery go into the laser first or the negative? Simple question, just want to be sure

Edit: scratch that second question it wont go in the wrong way

himhimself said:

I guess ill have to check the batteries voltage with a multimeter? (I think that's what its called)

Also I saw on the battery not to swap polarity....which made me think, does the positive side of the battery go into the laser first or the negative? Simple question, just want to be sure

Edit: scratch that second question it wont go in the wrong way

Click to expand...

For green lasers usually negative end goes first.


This is the reason I very often talk about safety, and quality of chargers:

^^^^^ That's the one I have! Funny. I'm going to keep keeping my eye on mine. I've had it over 2 years w/no problems. It looks like the one in the picture burned up right where the main a.c. power goes in.

Every green laser I've had is positive towards tailcap, negative to module

I am not trying to scare people, just to make them aware. What could happen.

I also do not advocate against any particular company for now.

I used to sell over 14 different types of li-ion chargers, with various results.

Basic rules (from my experience)

If you can have both - it is the best option- but either one would significantly decrease your risk of using fire extinguisher

1. Li-ion battery must be top of the line battery. (do your research - there are many battery tests/reviews available)
2. Charger must be designed with safe charging in mind. (fewer reviews, but still good starting point for using best charger)
3.Go to batteryuniversity.com, to help you understand even more.

You follow these basics, and you will be on the safe side.

Do your research on batteries / chargers (forums about batteries and flashlights are good place to start - there are some highly respected forums discussing batteries and chargers in depth ) .



Be safe

I just check all my chargers (all worth <$10). Three of them stop all current, and one continues to charge at 2-10mA to keep it full.

It would be helpful if you post what models you have.

So people have better picture what to buy, based on your recommendation.

They're random units with chinese markings or no markings. I'm just pointing out there's no reason to be paranoid about leaving them in the charger too long.

Quite unusual approach to safety related issue. But that's your opinion.
I would never recommend to any new user to do that - having in mind that 100s of battery chargers, and batteries (known, and unknown) being sold to the worldwide market.

This text below (from batteryuniversity.com) is very valuable piece of info for people who do care about safety.

Overcharging Lithium-ion

Lithium-ion operates safely within the designated operating voltages; however, the battery becomes unstable if inadvertently charged to a higher than specified voltage. Prolonged charging above 4.30V forms plating of metallic lithium on the anode, while the cathode material becomes an oxidizing agent, loses stability and produces carbon dioxide (CO2). The cell pressure rises, and if charging is allowed to continue the current interrupt device (CID) responsible for cell safety disconnects the current at 1,380kPa (200psi).
Should the pressure rise further, a safety membrane bursts open at 3,450kPa (500psi) and the cell might eventually vent with flame. The thermal runaway moves lower when the battery is fully charged; for Li-cobalt this threshold is between 130–150C°C (266–302°F), nickel-manganese-cobalt (NMC) is 170–180°C (338–356°F), and manganese is 250°C (482°F). Li-phosphate enjoys similar and better temperature stabilities than manganese.
Lithium-ion is not the only battery that is a safety hazard if overcharged. Lead- and nickel-based batteries are also known to melt down and cause fire if improperly handled. Nickel-based batteries have also been recalled for safety concerns. Properly designed charging equipment is paramount for all battery systems.

---------------


Keep it safe

brenner: the problem is that many chargers look exactly alike, but have different internals. Not to mention, I can only think of one charger that is reputed to charge cells correctly. Most of the rest are just CV. Best way would be to charge them yourself, but then that would require people to (gasp!) learn.

in the end, I generally just suggest people avoid Lithium anything in multi-cell lights, and if I have to recommend something, it is protected cells and a Pila IBC. No first-hand experience with the IBC, but it is reputed to actually use CC up to 4.2V, and then hold the voltage at 4.2 until current diminishes to a predetermined threshold.