[Narly1]

BTW, here is another great thread on LiPo's:

http://www.offroadrc.ca/showthread.php?t=23020

Narly1

[xxgg2]

So, higher MAH = longer run time?

Also, for example, 5000mah 20c can have longer run time than 5000mah 40c?

[Narly1]

Originally Posted by xxgg2

So, higher MAH = longer run time?

Also, for example, 5000mah 20c can have longer run time than 5000mah 40c?

Yes. The "C" rating is the peak (also known as the instantaneous or burst) current discharge rating of the pack expressed in terms of it's capacity.

In other words the peak current the pack can supply for short periods of time.

So 20C = 20 times the capacity of the pack (5000 mAH) which works out to 100 A (Amperes). Similarly for the 40C pack 200 A.

Narly1

[xxgg2]

One more question about charging a LiPo battery.

For example... if I have a 5000mah do I let the charger know that I have a 5000mah battery?
Reason for asking is because I read somewhere that I should charge it about 10~30% high mah?
Does that make sense?

[thrash metal]

when you charge a lipo its best to charge at 1 amp for every 1000 mah of capacity.

so your 5000 mah lipo you would charge at 5 amps, 2500 mah at 2.5 amps etc...

[Michael_Lambert]

Hey guys,

Just looking to pump the thread and ask a question as well.

I think i got a good grasp of how the Lipo's work and what I am going to need a 20C 5000 is ideal i think for what i would use it for.

Question is I will be running the VXL system so it does have Lipo low voltage protection, and it will be run in the slash, so a 5000 would give me plenty of run time. and thinking depending on cost going with a 3s for the max ability out of my brushless kit.

My concerns now are saftey, I am sure chargers/balancers have come along way since people started using Lipos. I would be picking up Lipos bags for charging them and keeping them stored in while transporting and storing.

Are there any other saftey issues i would need to watch for? I know everyone says you have to watch your packs all the time when charging which is hard when is a hardcase, in a lipo bag

How long would it take to charge say a 5000 pack at 5amps?

And what kind of concerns are there with Bashing and using Lipos?

Thanks again.

[ravagemaxx]

i charge my 5200 at 5amps and it takes about 1/2 hou- 45 min, im sure the vxl has a program on it somewhere so just look in the manual for it also check to make sure the vxl will hold the 3s u want to put in it.. im not fimiliar with the vxl.. all i know is that lipo is the bees knees

[Michael_Lambert]

It will hand the 3S packs. So your charging a 5200 3s pack in about 45 mins and how much run time would you get out of it?

Specs on the VXL
VXL-3m (WATERPROOF) ESC SPECIFICATIONS
Input voltage: 6 to 12 cells NiMH, 2S to 3S LiPo
Case Size: 26.5mm W x 46.5mm D x 22mm H
Weight: 38 grams
Motors: Sensorless Brushless
Motor Limit: None
On Resistance: 0.0005 Ohms
PWM Frequency 12,000Hz
Peak Current: 326A
Continuous Current: 52A
BEC Voltage: 6.0V DC
Motor / Battery Wiring: 16-Gauge Maxx® Cable
Transistor Type: MOSFET
Low Voltage Detection: 2-Stage indicators,
switchable (on or off)
Thermal Protection: 2-Stage thermal shutdown
Profile selection:

Sport Mode:
100% fwd, 100% brakes, 100% rev

Race Mode:
100% fwd, 100% brakes, no rev.

Training Mode:
50% fwd, 100% brakes, 50% rev.
Single-button setup: Yes, Traxxas EZ-Set®
Battery Input Connector: Traxxas High-Current Connector
Motor Connector: TRX 3.5mm Bullet Connectors

[ravagemaxx]

sorry my 5200s are 4s, i can get probably just under 15 min of racing on it with my esc/motor combo

[tekno]

I think i get lipos this is an example:

Formula:MAH/1000xC=Amp

My motor Specs:

* 2040KV
* Continuous Current 85A
* Peak Current 160A
* Max RPM 60,000

My ESC Specs:

* Compatible with 6-12 Cells (NiMh) and 2S - 4S (Lipo)
* BEC Voltage 6V
* BEC Current 3 Amps
* Low Voltage Cutoff Auto Detect (3.0V/Cell)
* Thermal Protection 96C
* Continuous Max Current 120A
* Peak Current 160A

The Lipo Specs:

*7.4V 2S 20C 5000MaH
*Continuous 20C
*Peak 30C (for a short period)

SO.....5000/1000x20C= 100A

SO......The lipo does 100A continuous and the motor is 85A continuous also, the ESC is 120A continuous.

SO.....do i refer to the motor amps or ESC amps for lipo referral?

Thanks.