LiPo Batteries - Help a Noob
#1
Ok guys bear with me here, I'm new to LiPo batteries, just trying to get back into racing 1/12 and touring car and I need new batts. Whats the go with all the numbers? 40C 50C etc? whats the 1 cell? 2 cell?
I've seen them around, in tourers, but what are the smaller ones in the 1/12th scale cars?
Is there a good link to where I can go and read up about them or get some info with regards to chaaging/discharging/balancing???
Any help appreciated.
Daniel
I've seen them around, in tourers, but what are the smaller ones in the 1/12th scale cars?
Is there a good link to where I can go and read up about them or get some info with regards to chaaging/discharging/balancing???
Any help appreciated.
Daniel
#2
Tech Master
iTrader: (2)
Joined: Jan 2009
Posts: 1,780
Ok guys bear with me here, I'm new to LiPo batteries, just trying to get back into racing 1/12 and touring car and I need new batts. Whats the go with all the numbers? 40C 50C etc? whats the 1 cell? 2 cell?
I've seen them around, in tourers, but what are the smaller ones in the 1/12th scale cars?
Is there a good link to where I can go and read up about them or get some info with regards to chaaging/discharging/balancing???
Any help appreciated.
Daniel
I've seen them around, in tourers, but what are the smaller ones in the 1/12th scale cars?
Is there a good link to where I can go and read up about them or get some info with regards to chaaging/discharging/balancing???
Any help appreciated.
Daniel
http://thetoyz.com/forums/index.php?showtopic=26695
http://thetoyz.com/forums/index.php?showtopic=6532
#3
Joined: Jul 2008
Posts: 11,530
From: Houston, TX
The "S" number is the number of cells wired in series and wiring in series causes voltage to add. Each lipo cell is 3.7v nominal so a 2S lipo is two 3.7v cells wired in series so the volltage is 3.7 + 3.7 - 7.4v nominal.
Lipo deal with 3 diff, somewhat confusing voltages. There is the nominal voltage - this is primarily used to talk about lipos - 2S is 7.4v, 3S is 11.1v 6S is 22.2v etc. When you charge a lipo cell, it reaches the cell maximum voltage of 4.2v/cell so a freshly charged 2S will read 2 x 4.2v = 8.4v, a 3S will be 12.6v anf a 6S will be 25.2v fully charged. Lipo cell max imum voltage is 4.2v/cell and can be damaged by overcharging to higher voltages. This is the reason a lipo capable charger is different and important to have and use. It avoids potential overcharging lipos.
There is also a minimjum lipo cell voltage that is important since if you discharge the cell below the minimum, there is potential for damaging the cell (it can swell up like a balloon) rendering the cell/lipo unsafe to use further. This minumim is about 3v/cell. A low voltage cutoff usually in the esc protects the lipo from overdischarging. There are separate lvc if you're using an esc without one.
The "C" rating as its called is the lipos discharge capability. Its a way of rating what the lipo battery can discharge - it is a function of capacity (mah) and the C rating. A 5000mah 40C lipo can discharge 5000/1000 x 40 = 200amps. Similarly a 50C 5000mah lipo can discharge 250amps. The C rating is also used in charging as in a lipo is rated for 2C charing - this means you can safely charge A 5000mah lipo AT 5000/1000 x 2 = 10amps, A 3 C charge would be 15amps. The higher the C allowed for charging, the shorter the charge time.
Here's some more detail -
http://www.rchelicopterfun.com/rc-lipo-batteries.html
Lipo deal with 3 diff, somewhat confusing voltages. There is the nominal voltage - this is primarily used to talk about lipos - 2S is 7.4v, 3S is 11.1v 6S is 22.2v etc. When you charge a lipo cell, it reaches the cell maximum voltage of 4.2v/cell so a freshly charged 2S will read 2 x 4.2v = 8.4v, a 3S will be 12.6v anf a 6S will be 25.2v fully charged. Lipo cell max imum voltage is 4.2v/cell and can be damaged by overcharging to higher voltages. This is the reason a lipo capable charger is different and important to have and use. It avoids potential overcharging lipos.
There is also a minimjum lipo cell voltage that is important since if you discharge the cell below the minimum, there is potential for damaging the cell (it can swell up like a balloon) rendering the cell/lipo unsafe to use further. This minumim is about 3v/cell. A low voltage cutoff usually in the esc protects the lipo from overdischarging. There are separate lvc if you're using an esc without one.
The "C" rating as its called is the lipos discharge capability. Its a way of rating what the lipo battery can discharge - it is a function of capacity (mah) and the C rating. A 5000mah 40C lipo can discharge 5000/1000 x 40 = 200amps. Similarly a 50C 5000mah lipo can discharge 250amps. The C rating is also used in charging as in a lipo is rated for 2C charing - this means you can safely charge A 5000mah lipo AT 5000/1000 x 2 = 10amps, A 3 C charge would be 15amps. The higher the C allowed for charging, the shorter the charge time.
Here's some more detail -
http://www.rchelicopterfun.com/rc-lipo-batteries.html




