Charger question

Yes, I am a newbie with this. I am thinking about buying rechargeable batteries for my e35(18650). Now I understand the dangers of rechargeable batteries. Ive read that we must be on top of voltages and times during charging. Now chargers like the nitecore i4 say they shut off after charging is complete. How safe are these and what kind of charging timeframe should I expect?

SM83 said:

Yes, I am a newbie with this. I am thinking about buying rechargeable batteries for my e35(18650). Now I understand the dangers of rechargeable batteries. Ive read that we must be on top of voltages and times during charging. Now chargers like the nitecore i4 say they shut off after charging is complete. How safe are these and what kind of charging timeframe should I expect?

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Almost all the decent chargers follow an charging algorithm that stops adding charge after they reach the termination point.

The TIME to charge depends on the mah of the 18650 (A 3400 mah 18650 will take longer than a 2600 mah 18650, and so forth...), as well as how low you drained them before putting them on the charger (You can top off Li-ions, they don't have a "memory effect", etc....and the DEEPER you discharge them, the more wear and tear on the cell, and, the longer the recharge time.)

Sometimes they max out on the total juice, so charging more cells can be slower than charging one, etc....so the specific charger, with specific cells, can result in variable performance/charge times.

Figure a few hours to recharge... ~ 2 - 3 if under faster conditions, ~ 3 - 8 under slower conditions...for most of the chargers you might be looking at, and, cell combos.

TEEJ said:

Almost all the decent chargers follow an charging algorithm that stops adding charge after they reach the termination point.

The TIME to charge depends on the mah of the 18650 (A 3400 mah 18650 will take longer than a 2600 mah 18650, and so forth...), as well as how low you drained them before putting them on the charger (You can top off Li-ions, they don't have a "memory effect", etc....and the DEEPER you discharge them, the more wear and tear on the cell, and, the longer the recharge time.)

Sometimes they max out on the total juice, so charging more cells can be slower than charging one, etc....so the specific charger, with specific cells, can result in variable performance/charge times.

Figure a few hours to recharge... ~ 2 - 3 if under faster conditions, ~ 3 - 8 under slower conditions...for most of the chargers you might be looking at, and, cell combos.

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Another newbie question, do you loose performance with a lower mah than a higher mah? I just purchased my first 18650 light and am looking for a high quality battery and charger. I was looking at eagletac 3400 but i know they offer different levels.

Hello Deadly Pooh Bear,

Welcome to CPF.

Capacity is measured in mAh or for larger batteries in Ah. The more capacity you have the longer run time you have.

Think of it like a gas tank. Your car will perform just fine with 1 gallon of gas, but will do so for a longer period of time with 5 gallons.

Unlike the car example there is often a trade off with batteries. In order to get more capacity into the same sized package, the internal set up of the cell ends up being changed a little. This can effect performance if your light operates at extremes. For example a 2000 mAh cell may perform very well up to loads of 10 amps. The same load applied to a 3400 mAh cell may see the voltage drop lower under the load and the cell may heat up to higher temperatures. This causes additional wear on the cell and you don't get the cycle life out of it you were hoping for.

In order to determine performance you first need to know the load your light places on the battery. Then you need to know how the battery responds to that load. There are some data sheets available and some of the cells have been tested under differing loadings and you can review those tests. If all else fails you can buy a cell and the needed test equipment and test it yourself.

Once you have all the pieces matched up you can then give it a real world test and see how well it works and how long it lasts.

If you light doesn't push things to the limits you can probably get by with almost any cell and if the labeled capacity reflects the actual capacity the higher mAh will give you longer run time.

Tom

Tom,

Thank you for the good information. I currently have a Klarus XT 11 820 lm, Klarus XT 10, I have been using 4 Sevens CR123's in them without a problem. I just bought a Thrunite TN 12 and plan on running a rechargable 18650. I'm just into the game and after poking around the site I educated myself on the dangers of these batteries. With that being said I plan on getting rid of the 2x CR123 in favor of an 18650. I wish I could find a battery 101 guide where I could gain basic knowledge on this topic so I could better understand all these great battery tests and reviews on this site.

Deadly_Pooh_Bear said:

I wish I could find a battery 101 guide where I could gain basic knowledge on this topic so I could better understand all these great battery tests and reviews on this site.

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http://batteryuniversity.com/

Thank you for the website. There is a ton of great information and im learning a lot! :twothumbs