As many know the C rate of Lipo packs are not very reliable and pretty much made up as a way to sell packs. You can check out this video we did to show how packs with various C rate claims test out.   

In an attempt to let our customers know the difference between our packs we created a True Spec Amp rating which uses the internal resistance of the cells and the mAh to give the amps the cells can safely handle.   In theory the higher the amps the stronger the pack will be.   There is one small issue with this as it takes into account the mAh of the cells.   We decided to use a different method to show the packs rating which is more accurate as we use the voltage under load to determine the cells rating.  We call this Power Factor and we get this number by loading up a fully charged pack at 100 amps and taking the voltage of the pack at 5 seconds.   This is similar to the amps rates you can see under acceleration in a normal 1/10^th size vehicle.   We take the voltage of the pack and divide it by the number of cells and this gives us the voltage per cell.   A 2S pack that is at 7.84 voltage at 5 seconds under 100 amp discharge would have a 392 rating which 3.92V per cell.  If we offer this model as 3S, 4S and 6S you can multiply the 392 by number of cells.  A 6S pack would 2352 or 23.52V.  The reason why we picked 100 amps instead of a lower amp rate or higher amp rate is we feel the higher the amp rate the more difference you can see in the cells voltage drop under load.  We decided on 100 amps as this would cover the range of packs we offer from big to small as lower mAh smaller pack will have more voltage drop under load. 

An example of how this rating gives more accurate results then the True Spec Amp rating we have the Amp rating on our 80175-2S2P Extreme Graphene and our 52162-2S2P Extreme Graphene packs.  The 8000 has a rating of 175 amps and the 5200 is rated at 162 amps.  Under our Power Factor test the 8000 has a rating of 396 and the 5200 is rated at 397.   This means the 5200 will have a bit more punch power under heavy acceleration.   The difference is not much so if your type of racing uses a good amount of mAh then the 8000 could be better as it will hold voltage longer under load due to the higher mAh.  The weight of the pack also needs to be considered as if a pack has the same Power Factor rating as another pack but is lower in weight then it will be faster as the vehicle will have less weight to move.

Here’s the Power Factor rating on our packs.  The power factor is listed first with the packs part number in second.  You can also check out the Power Factor rating of each pack by clicking on specifications on the packs page.

2S shorty packs:

369PF-50369-2S2P 

385PF-51112-2S2P

2S Full Size:

385PF-65120-2S2P  The DV series 6500-3S , 4S and 6S have the same Power Factor.

385PF-80110-2S2P   The DV series 8000-3S , 4S and 6S have the same Power Factor.

390PF-52390-2S1P

396PF-80175-2S2P   The inboard version of this pack has the same Power Factor.

397PF-52162-2S2P

3S:

357PF-40357-3S1P

370PF-5097-3S1P    The Premium series 5000-4S LCG and 5000-6S have the same Power Factor

380PF-72380-3S1P   The DV series 7200-4S and 6S have the same Power Factor.

390PF-94390-3S1P   The DV series 9400-4S has the same Power Factor

Below is a picture of the equipment used to load up the packs.  It consists of a 40A/200watt Rigol load tester and three 500 watt loads for a total of 1700 watts of discharge.   This means a 2S pack could be discharged at 202 amps assuming the cells , connectors and wires could handle such a load.  An external digital voltmeter is used to register the voltage at every second.