Showing posts with label lipo. Show all posts
Showing posts with label lipo. Show all posts

Sunday, April 6, 2014

LiPo Battery Charging and Storage

The Charming Mrs. EastBay RC puts up with a lot in the service of her husband's various hobbies, but one place where I'm pretty sure she would draw the line is burning down EastBay RC's international headquarters.  I've experienced first hand the rather unpleasant experience of having a LiPo battery short out and burst into flames, so I'm a stickler for careful battery charging, handling, and storage.
 Here's my main charging station.  That's a HobbyKing 4 port charger powered by an old PC power supply.  The charging bunker consists of a standard sized concrete block sandwiched between two flat blocks.  I painted everything white to look a little better and to keep dust, etc from coming off the concrete.  I've notched the block so that battery leads can fit in with the top closed.  There's a smoke detector on top, and a fire extinguisher next to my workbench.
 Here's my battery storage bunker.  It's a fireproof safe that I salvaged out of recycling.  It weighs a ton.  The unit was open with the door bolts set in the locked position.  I tried (unsuccessfully) to figure out how to set a new combination, but it works perfectly as a battery storage bunker.  The door is heavy, so I just need to be careful not to drop it on my fingers.
Here's a view showing some batteries.  One day when I have some time to kill I'll put some shelves in to make the storage a bit more tidy, but for now I'm really pleased with it.
Prior, I stored everything in an old ammo box, which was a bit more restrictive in space.  The Internet seems to think that it would be fine for containing the open flame of a burning LiPo.  Prior to that, I kept everything stored in a concrete block similar to my charging bunker.  I've also got some LiPo bags for use on the go.





Bottom line:

  • Take LiPo charging and storage safety issues seriously.  Watch some youtube videos on "lipo battery fire" to ensure that you do.
  • Get something to put your batteries in while charging.  I think a LiPo is actually a good solution, but it's a bit more convenient to have a larger bunker if you've got the space.
  • Always stick around while your batteries are charging.  I typically charge while I'm at my workbench so it's not a problem for me.
  • Keep a fire extinguisher nearby.  This applies to your workshop or hobby table as well.
  • Be careful, but not anxious.  I've never (thank God) been in a car accident, but I still wear a safety belt when I drive.  Same here... it's a bit overkill until the one time it isn't!
  • If this save you from burning down your place and getting in big trouble with the family, you owe me a verrrry nice dinner!
update: here's my bag of sand that I was using to cover the hole in the concrete block before I switched to the flat concrete block.  The reasons I switched were:
  • I wanted to move the charging station from the garage to my workshop so it would be a bit easier to attend to.
  • I was in deathly fear every time I handled the bag, afraid it would split open and I would be vacuuming sand for hours.
  • After watching a couple of youtube videos I think the concrete topper will contain any open flames.



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Sunday, June 24, 2012

Travelling with model aircraft and LiPo batteries

Some hints from Chris Anderson:

I carry the drones in a Pelican case, which is checked luggage
I enclose a note in the case explaining what they are, for the TSA to read. I use phrases like "robots for a competition" rather than use the word "drones".
I carry the LiPos in my carry-on luggage, in a bag that clearly marks them as batteries.

And a document with guidelines for travelling with batteries.


Saturday, February 25, 2012

Open Source Lipo Charger

Very Nifty! Paul Asselin has an open source hardware design, based on the Microchip MCP73831.  You can download the schematics and Eagle files directly. He also sells a kit or completed unit.

Monday, September 19, 2011

LiPo Battery Voltage numbers


Some handy voltage numbers.


cells                   1S      2S      3S      4S      5S      6s
nominal voltage         3.7     7.4     11.1    14.8    18.5    22.2
absolute low voltage    3.0     6.0     9.0     12.0    15.0    18.0    
low voltage warning     3.3     6.6     9.9     13.2    16.5    19.8
maximum voltage         4.2     8.4     12.6    16.8    21.0    25.2
storage voltage         3.8     7.6     11.4    15.2    19.0    22.8

Monday, July 18, 2011

Interesting battery wiring guide

Need to hook up batteries in parallel or serial configurations?  This page has a nice application that will show you just what you need to do.

All about lipo balance connectors

TJinTech has a great article on this, with lots of nice diagrams like this one.

Sunday, July 4, 2010

Ordered LIPO bags

From ebay, being shipped from Hong Kong. Bought 4 bags, I'm going to try and set one on fire just to make sure they work. Price for 4, $18.36.