Li-Ion Battery Care

Here's what you need to know for care and use of Lithium Batteries.

A little bit of basic information of how and why lithium batteries are used:


Lithium battery chemistry is used because of one important fact.  Normal store bought batteries (including normal rechargeable NiCad or NiMH) have a very steep voltage decline during use.  You have probably noticed that lights, remote control cars, or even your car/truck that on battery power, the light output (or speed of the RC) declines steadily from the moment its turned on.  Lithium batteries are designed to instead maintain a "operating voltage range" from start to finish.  So that decrease is mostly unable to be noticed till right near the end of a charge and doesn't start until 60-80% of the "capacity/run time" has been used.  

This is part of how bike lights and flashlights are able to maintain rated output for most of their run time cycle.  When a light starts to slowly dim (we call it "dropping out of regulation") it means you are very close to the end of the charge capacity of the batteries and its TIME TO RECHARGE.

It gets a lot more technical and in depth but for sake of simplicity and quick reference, just the information that pertains to ALL USERS for safety and reliability of lithium cells is covered here.   Branded cells (all Ituo and Rakc offer is high quality cells from EVVA, BAK, Panasonic, LG, Samsung, Sanyo) cannot go critical to that extreme, which is why using "cheap" batteries and chargers is strictly prohibited with any of the products we carry.  Its for your safety and the performance/reliability of our products.

 Lithium Care instructions:

  1. Use quality chargers with output rating that matches the batteries to be charged.  Built in USB chargers work with any standard 5V USB charging system.  No need for a separate charger for the loose cells.  Special chargers are widely available but as stated above, use quality and branded products ONLY.  If its extremely cheap (under $20 and not a brand like XTAR for example), its not safe to use and will void battery warranty.  For wall adapters for battery packs, they must be rated for 8.4v output and no more than 2 Amps charging current.  The inexpensive chargers found with "cheap china made lights and batteries" may state they are correct voltage and output HOWEVER, it has been proven that they can and will charge to a higher voltage.  This is the number one reason for cell failure and fires can result.  Over charging the voltage. ALWAYS CHARGE WITH CHARGERS RATED FOR THE VOLTAGE OF THE BATTERIES THEY ARE CHARGING.  Single loose cell= 3.7/4.2V (numbers refer to same type, 3.7 is nominal voltage, 4.2 volts is the voltage each cell will read when fully charged), battery packs are 8.4V (2x 4.2v cells in series) unless otherwise specified.  Make sure your battery and charger voltage always match before charging.
  2. Do not try to over discharge the batteries.  Once the protection circuit engages and cuts power DO NOT attempt to force the light to work any more.  This will over discharge the cells.  This is what LEADS to the second reason for cell failure and possible fire.  Once a battery has "cut off" you need to charge it AS SOON AS POSSIBLE.  Not required to fully charge, but attempting to recharge to 50% or more is advised.  This is because the inherent property of ALL rechargeable batteries.  Self discharge.  If stored in a fully discharged state, the cells can drop well below safe voltage.  This over discharges the cells and causes cell failure.  Its not the OVER DISCHARGE that creates the dangers, its trying to recharge them after. 
  3. Do not leave batteries or chargers in direct sunlight or anywhere that gets overly warm like a closed up shed/garage or inside a vehicle.  If battery is in a protected case (like a camera case for example) on your vehicle floor or in the rear storage area WITHOUT ANY DIRECT SUN EXPOSURE TO THE CASE, then leaving them in your vehicle is ok for brief periods.  Batteries should always be stored in a cool, dry place.  They do not react well to high temperatures, can begin to leak especially if fully charged.
  4. Do not allow loose cells or battery packs (internally) to come into contact with water and do not submerge.  This will cause a short that will cause cell failure.  All of our products are water resistance (except loose cells) but cannot be submerged or stored a wet environment.
  5. Do not leave batteries that are charging unattended and do not charge on a flammable surface like carpet, wood,  or plastic for example.  Any cell no matter how high quality can fail.  And they will generate heat, in the right conditions it can still cause a fire.  However, unlike low quality cells, they will NOT burst into flames on their own.  If you need to charge unattended, please do so by placing the batteries being charged on a metal pan, cookie sheet or similar and place all of it on a metal or stone based surface with nothing flammable above it.  NEVER try to charge a pack on carpet or unprotected wood surface, attended or otherwise.  Tile floor away from walls, masonry below a fireplace (not being used of course) as common, "in home" examples of safe places to charge.


  1. Ituo and RAKC Industries accept no responsibility for any damages caused by Lithium batteries or charger.  This includes any personal injury or personal property damaged due to improper care and handling of our products.  If proper care and use is followed, in no way is any personal property damage or personal injury possible due to battery failure.
  1. We recommend using only supplied or specified chargers unless you have other certified and quality chargers (basic UE certification DOES NOT COUNT and is often illegally posted on cheap and dangerous chargers).  Use known brands that are proven quality.  Doesnt require spending alot, just not "cheap imports" from places like ebay, amazon third party sellers, etc.
  2. IF YOUR LIGHT USES LOOSE CELLS INSTEAD OF A BATTERY PACK, USE ONLY PROTECTED, BRAND NAME, 18650 or 26650 cells (whichever is specified for the light)  USB lights DO NOT protect unprotected cells from over charge or over discharge.  Warranty is void if unprotected cells are used and a failure of the cells/damage to the light or accessories occur.  All Batteries included or sold by Ituo and RAKC Industries are not only branded, but use high quality protection circuits for both over charging and over discharging protection.
  3. Dispose of batteries immediately if large and thick corrosion is seen on the cells, a "gel like" substance is present on the cells or they start to become hot during charging.  The substance lithium cells can leak if they fail is very toxic and highly corrosive.


Like anything.  Use and care for properly and they will be problem free for years.  Ignore the instructions and abuse them, they will fail and risk leaking or worse.  Our products are proven, top quality batteries and protection systems, but even the best of the best can fail.  Even then none of the batteries we carry will do any damage except toxic gel/fumes vented from the cells.  However we know sometimes people have a slim budget to work with which can cause a person to see what looks to be "great deals" on batteries.  If they don't have a brand name listed above (or another quality brand I forgot to mention), we would classify them unsafe.

 If you have any questions or just need clarification on anything, feel free to contact us with your questions or concerns, we're here to help.