A "puffed" LiPo battery on the left next to a normal battery. The result of leaving the battery fully charged for an extended period of time.

A “puffed” LiPo battery on the left next to a normal battery. The result of leaving the battery fully charged for an extended period of time.

Lithium Polymer (LiPo) batteries power many of the things we all use on a daily basis.  From cell phones to laptops to cordless drills, there are probably a half dozen or more LiPo powered devices in an average modern home.  LiPos have many advantages over other battery types which explains why so many manufacturers use them in their products.  But what many people don’t realize (and until recently I admit I was one of them) is that, if not properly maintained, a LiPo battery can be extremely dangerous.  A quick search of the Internet for “LiPo fire” reveals that although relatively rare, when it does happen the results can be disastrous.

But what many people don’t realize (and until recently I admit I was one of them) is that, if not properly maintained, a LiPo battery can be extremely dangerous.

To properly charge, maintain and use a LiPo battery (such as the 10,000 mAh battery we use in the BlueROV2) requires proper equipment, a safe environment for charging/storage and constant monitoring.  It is critical that you read and fully understand how to safely use LiPo batteries and there are many sites on the net that go into great detail (here’s one), but here’s some tips:

  1.  Always use a battery charger designed for LiPo batteries and be sure to fully understand how to use it.
  2. Charge your LiPo batteries in a fire safe location that you can easily monitor, preferably out of doors and away from any structures or flammable materials.  Read this article about how a charging accident nearly destroyed a home.
  3. Never over discharge a LiPo battery, be careful to monitor it’s voltage during use.
  4. Store your LiPo batteries in a fire proof box, such as a military surplus ammo can.  Watch this video to learn how ineffective “charging bags” are in the event of a fire.
  5. Never leave a LiPo battery fully charged or discharged for an extended period of time.  Use your charger’s “storage” mode to return the battery to a safe voltage if not using it for more than a few days.
  6. NEVER puncture a LiPo battery and ALWAYS protect the battery from physical damage.  Watch this video of what might happen if a battery is damaged.

Is there a safer alternative to LiPo?  Yes there is!  Lithium Iron Phosphate (LiFePO4) batteries  LiFePO4 batteries share many of the good qualities of LiPo batteries:  lightweight and small size for the power they provide, but with far less risk of fire or explosion.  Quoting an article on BatteryStuff.com, “The LiFePO4 batteries are the safest type of Lithium batteries as they will not overheat, and even if punctured they will not catch on fire.”

LiFePO4 batteries share many of the good qualities of LiPo batteries: lightweight and small size for the power they provide, but with far less risk of fire or explosion.

So what battery should you use with your ROV?  That’s really up to you.  LiPo batteries are in use so many places and by so many people with only a small risk of fire or damage.  But that risk is real and shouldn’t be ignored.  Personally, I plan on switching to LiFePO4 batteries.