Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

LPF Donation via Stripe | LPF Donation - Other Methods

Links below open in new window

ArcticMyst Security by Avery

LiIon battery best practices

Joined
Dec 14, 2010
Messages
315
Points
0
Well, I have been searching for about 30 minutes trying to totally get my story straight about the whole charging battteries deal... Basically the idea that you shouldn't discharge them too much, nor overcharge them either.

The part that I'm stuck is that there's no one place that I've found that is like a guide on how to treat your batteries. Up until now, I basically just bought batteries, and the only experience with LiIon batteries is in my BlackBerry lol


Anyway.
What I was hoping to do was make a noob-guide for battery charging, but then I realized I don't have all the information I need readily available.

That being said, I do have a bunch of questions I was hoping we could get some answers to and I'll make a guide of sorts for new folks like myself that are scared of blowing a battery up by accident lol


So my questions are along the lines of:
How do you know if you're getting close to needing to charge your battery?
How do you prevent overcharging?
What is this 'protected battery' thing, what does it do and what are the up/downsides to it?
What are some best practices you folks follow to get the most out of your batteries?
In what situations could a battery actually explode?
For someone who isn't super savvy with electricity, when we talk about mAh, resistance and voltage/amperage, how do those all play into the operation of batteries in laymans terms? The lower the resistance the better, because it means less heat, but what are the other benefits?

I think those are enough questions for now but I'm going to scour other threads trying to decipher answers on my own.

Thanks in advance for any clarification that could be offered :)
 





Joined
Oct 26, 2007
Messages
5,438
Points
83
Just buy a charger that handles all of that for you. Then just make sure you don't: 1) short out the battery leads (i.e. connect a wire from the + to - directly) and 2) don't run the battery until it is absolutely dead.

Protected cells have a circuit-board that is supposed to prevent the above problems. Often it means if you do accidentally short it or run it too low that it won't overheat or cause damage, but that the battery will be rendered inoperable and you'll probably need to replace it.

mAH is the amount of current (milliamps) that can be run for an hour. If you have a 3200mAH, you can output 3.2Amps of current for an hour. It is a measure of how much capacity your battery has, given how many mA of current your circuit needs. So if you have a laser that uses 200mA, you can compute how long your battery will last.

Resistance, I'm not sure. I usually don't measure it or think about it in batteries. Has an effect on/correlation to battery health though if I remember correctly.

Read up about your specific battery type about how to get the most out of it. For LiPo/LiIon usually you want to recharge it before it goes too low (like below 50%), but not leave it on the charger too long, as the trickle charge may degrade the battery. NiMH batteries don't have a permanent memory effect like NiCads, but do need to be fully discharged from time to time to reset themselves if I recall. Don't buy NiCad batteries; there's no need for them these days.
 
Joined
Dec 14, 2010
Messages
315
Points
0
Great! Thanks so much for the response :)

NiMH batteries, aren't they not as capable of outputting higher powers needed for higher output lasers though?

I guess my biggest thing is that I've heard stories of their LiIon batteries exploding and I want to do everything I can to prevent that from happening to myself :)

Otherwise, all of your explanations make sense, and I appreciate your help!
 
Joined
Dec 6, 2008
Messages
1,581
Points
63
enigmahack;

Lithium ion cells are the most advanced technology available.

Because of high volumes produced for notebook batteries, they are constantly improving in safety and power.

U.L. 1642 specifies stringent testing procedures to insure safety.

I believe this U.L. testing is your best assurance, to obtain a cell manufactured to quality standards.

LarryDFW
 
Joined
Jan 3, 2011
Messages
35
Points
0
well I have learn some tips from my electronic engineer and he used to tell me this

1. Li-ion batteries are very sensitive to heat and 7 out of 10 cases the battery got damaged by HEAT (well in my case I lived in tropical country)

2. Li-ion batteries has very sensitive to voltage during charge, fast charger will shorten the life of the batteries as it pump more voltage result in higher HEAT (as 1 of the reason) always use slow chargers if possible

3. Do no discharge your battery below 40% or completely drain your battery, Li-ion has no memory effect and by doing this it shorten your battery life very fast. only do a complete cycle charge/discharge every 4 to 6 month just to reset the battery IC to proper show the current health of batteries (applies only to IC / chipped li-ion batteries)

4. Li-ion with proper circuit will not over charged but it is advisable to constantly charge your li-ion batteries, I did this to my ipod 1st Generation and surprisingly the battery still in tip-top condition even it is over 5 years!!!

5. don't worry on the charge cycle, when you charge your batteries at 80% state it is not considered as 1 cycle... a full cycle is a accumulative of 0-100% charge then it is considered 1 charge cycle.

hope it helps although some people may dis-agree with no.5
 
Joined
Oct 20, 2010
Messages
301
Points
0
Battery University Table of Contents

this is the best site for all batteries :)

I bought the book "Batteries in a Portable World" second edition for less than $5 on Amazon.com. I see there is now a third edition. It is an excellent book well worth the read for heavy battery users like us. There has been much improvement in Li-Ion technology over the last 10 years. The new version will be available from the above site.
 
Last edited:
Joined
May 12, 2010
Messages
23
Points
0
Sorry for bring up an old thread, but I wanted to ask a question about battery overcharging. I charged the battery I got with my 100mW green laser, but I forgot about it and left it to charge a little bit too long. So it got charged to just under 4.1 V. Its a 18650 2400mAh ultrafire battery with no over charge protection. It does say that full charge is 4.2 V on the side of the battery. But what I would like to know before I use it, is there a risk of damaging my laser by using the battery at this voltage, or will my laser more than likely be fine? I'm not worried about the battery so much, I just want to make sure it will be safe to use with my laser. If not, what would be a handy way of discharging it down to a lower voltage so that it would be in a safe operating range?
 

rhd

0
Joined
Dec 7, 2010
Messages
8,475
Points
0
Most 18650s charge to ~4.1V. That's normal, that's fine, that's a "full charge" for these batteries. Unless it's just flat out the wrong battery for your laser, then you shouldn't have a problem. Any laser designed for a typical 3.6V lithium-ion would be designed to deal with that battery at it's full charge of ~4.1 or 4.2V.
 
Last edited:
Joined
Nov 1, 2010
Messages
479
Points
18
I bought this multymeter, so I can measure with it battery voltage and thus knowing exactly when it is fully charged and when it is discharged to such an extent which requires a recharge.
 
Joined
May 12, 2010
Messages
23
Points
0
rhd, thanks for the reassurance. When i thought about it after posting I thought that surely if thats the full charge of the battery the laser should be designed to handle it, but its good to get confirmation from someone who knows more about it. Cheers.

snoutke, yeah I have a multimeter already, thats how I could tell the battery was at ~4.1V. I actually used a usb cable with one end cut off to measure the voltage from the usb's power cables, as a means of testing the accuracy of the multimeter as well, because I wasnt sure a cheap ebay multimeter would be very good. Its fine though(although I did have to solder a loose wire back in place when I got it). Its actually a similar model to the one you linked to, but slightly different.
 




Top