HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Mar 20, 2012, 11:58 AM
Registered User
United States, WA, Longview
Joined Sep 2011
42 Posts
Question
lithium ion batteries for power

Hello All

Just a quick question from a noobe. Can anyone give me some info on why you shouldn't or can't use lithium ion batteries instead of lipo batteries.

I have a drill motor that uses a lithium ion battery (12V) and it just need to be plugged into the charger that came with the drill for 30 minutes to recharge it. It's seems like much less of a hassle to recharge them than it is a lipo, where you have to worry about all sorts of things like fires, overcharging, balancing, over-discharging, etc. The battery that the drill uses is 1.3Ah and is fairly light in weight at only 190 grams. It seems logical to me that if the lithium ion battery will power a large, high torque, drill motor, it should also be able to power 4 little brushless motors for a decient amount of time without all the hassle involved in maintaining and charging lipo's. I know that discharge time is involved but the drill can be used for what seems like hours before it needs to be re-charged.

Before anyone starts to talk about constant running time for the 4 motors and the on/off running time of the drill, and the voltage difference between a 3s lipo at 11.1 volts and the 12 volts of the lithium ion battery, something that a simple voltage regulator would fix, it seems to me it would balancd out. Wouldn't the high current draw rate of the the high torque drill motor each time it is started and the current draw it uses to turn a drill through a piece of wood or to drive screw be equivical to the constant current draw rate of the constantly running little motors? I may wrong and totally out of the park here but one doesn't learn by not asking questions. If anyone who may know something about this sort of thing can help out with any info I would appreciate it before I waste time and effort by trying to experiment with using one of these drill batteries to power my quad. Thanks
alfstan is offline Find More Posts by alfstan
Reply With Quote
Sign up now
to remove ads between posts
Old Mar 20, 2012, 12:12 PM
Live to ride... and fly!
Tres Wright's Avatar
Forney, TX
Joined Mar 2002
15,165 Posts
190 grams is too much weight for a 1300 mah pack, a lipo in that capacity would be about half the weight. And in multirotors you don't want to haul more weight than you need, it greatly affects the performance. If you're looking at something like a DJI quad or Witespy or similar, you want at least a 2100 pack, you wouldn't get much flight time on a 1300 pack.

Quote:
Originally Posted by alfstan View Post
It's seems like much less of a hassle to recharge them than it is a lipo, where you have to worry about all sorts of things like fires, overcharging, balancing, over-discharging, etc.
Most accidents happened back before the current range of smart chargers came out, we used to have to set charge rates and cell counts manually and the charger would just charge whatever was programmed in. So if you set a 2 cell pack to charge at a 3 cell rate, you didn't get any warnings at all and it could easily result in an exploded pack and a fire. Modern chargers are much safer. I still take charging precautions- I charge in the garage, only when I'm there, put my packs in a lipo bag while charging, and store them in a fire safe when not in use.
Tres Wright is offline Find More Posts by Tres Wright
Reply With Quote
Old Mar 20, 2012, 12:18 PM
Linux Compatible
machina's Avatar
United States, DC, Washington
Joined Dec 2007
418 Posts
THe problem is you don't know the C rating for the battery. Running one high amp motor is different than running 4; unless you're sure the battery can provide 40amps or so continuously (key word there) you don't know if you are going to pop the battery when you try to fly it. Drills operate in short bursts; much different than sustained flight.

There also isn't that big of a difference between lipo and lion batteries. Lipo is, after all, Lithium Ion Polymer batteries. Actually Lipo's are more dirable that lion batteries because the electrolyte is held in a solid polymer.
machina is offline Find More Posts by machina
Reply With Quote
Old Mar 20, 2012, 01:05 PM
Registered User
Hawaii
Joined Feb 2003
5,958 Posts
The A123 or LiFe batteries are a very good alternative to power the multi rotors. The only disadvantage is weight. They are quite a bit heavier than the lipoly packs. They also have a different voltage and you need to set your charger differently. The advantage is that they are very robust and can handle a lot of abuse and are much more durable than lipoly packs.
SeismicCWave is offline Find More Posts by SeismicCWave
Reply With Quote
Old Mar 20, 2012, 05:21 PM
Spiritual Hovering
Coptaire's Avatar
Paris, France
Joined Sep 2010
257 Posts
Quote:
Originally Posted by SeismicCWave View Post
The A123 or LiFe batteries are a very good alternative to power the multi rotors. The only disadvantage is weight. They are quite a bit heavier than the lipoly packs. They also have a different voltage and you need to set your charger differently. The advantage is that they are very robust and can handle a lot of abuse and are much more durable than lipoly packs.
Exactly.
3.3v per cell, more linear discharge (lower voltage drop), the punch is different (better, I use them in 5S).
But beware of low temperature, not the same behavior @25C than @0C
Coptaire is offline Find More Posts by Coptaire
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Are Lithium Ion the same as Life batteries? Thermalin Batteries and Chargers 3 Nov 23, 2011 09:12 PM
Question charge lithium ion batteries with icharger 106b saedy Batteries and Chargers 11 Oct 25, 2011 09:07 PM
Discussion Better Lithium Ion Batteries on the way from Berkeley Lab Ron101 Electric Ducted Fan Jet Talk 21 Sep 29, 2011 01:03 PM
Discussion Lithium-sulfur batteries could store triple the power of lithium-ion jonnyspeed Batteries and Chargers 2 Jun 10, 2009 04:13 PM