Speed Assault

How do you guys calculate what size Lipo to get ?
Trying to decide what Lipo size to buy, Example: 3300mah that is a 25c or 3300 40c , or 4300 25c



Been doing RC for many years, recently RC crawling but now Getting into Short Course racing, 2wd open class. Just bought a Tekin Redline 10.5 sensored brushless and have not run it yet. Will be racing/running on a small short course track.

When I practice, been using a Thunder p 2250 30/60c , lasts 10 minutes on a castle 2200kv or 15+ minutes on a Old reedy mod brushed.

How are these ? :

Thunder Power RC G4 Sport Race 25C 3300mAh 7.4V 2 Cell LiPo 2SSRD 3300

Thunder Power RC G4 Sport Race 25C 2700mAh 7.4V 2 Cell LiPo 2SSRD 2700 Lipo

Thunder Power RC G4 Sport Race 25C 4300mAh 7.4V 2 Cell LiPo 2SSRD 4300

Thanks

Dialed_In

I'm far from an expert but you need to find out how many amps your motor/s will pull as constant and peak and then find a battery that is capable of fulfilling those needs.

To find out what your battery is capable of you multiply 2700mah X 25C = 67500/1000 = 67.5amps constant

for peak/burst it would be 2700mah X 50C = 135000/1000 = 135amps peak/burst

Then you can do the same thing for the other batteries but it looks like the site shows accurate constant and burst rates.

FWIW, I was told by CC that they recommended a minimum of 5000mah battery. They mentioned something about it being better for the Monster ESC.

Speed Assault

yep that's how you calculate the battery.

as far as what CC said, what application is that ?

I'm running a Tekin 540 size brushless 10.5
.

Yosh70

Castle's MMM 2200Kv combo requires a minimum 125A discharge.....some are saying 150A. Easy way to look at a lipo to see if your filling those needs is take the 1st two numbers of the Mah rating (in your case 2.2) times the discharge rating (30C) which is 66A. Seriously underpowered for a 2200Kv 1/8th scale motor IMO.

What exactly are you racing? 2wd SC 1/10 with a Castle 2200Kv motor? Or something else? I'm just a little confused.

Dialed_In

That was for the 2200kv and 2650 Mamba Monster ESC/motor combos.

nick 30

you want something like a 4s to give you what you need, but you esc has to be capable of sustaing the amp draw

jermpool

So if my esc specs say 200a continuous and battery says 100a continuous, am I ok? Or do I need to change something?

nick 30

thats fine, 200a esc and 100a batt is good, your burst current on 200a speedo should be about 300a for 10 seconds, more that enough

i came over from rc boats (back to cars as its to cold for rescue swimming) and i uselipo's all the time,i use 60a, 120a and 200a esc's so everything falls in between these plus i solder extra capacitors onto my spedoo's to help with voltage spikes

when i choose a batt i look at the motor i have so it would be high kv motor = low volt batt, low kv motor = high volt batt, this will give you rpm's

another thing about the mah rating is this will indicate the amount of runtime you can get, sometimes you'll find that what the manufacturers are suggesting will be overkill, i have 2 sets of packsfor all my boats, we do 5minuteraces and we have to do as many laps as wecan

personally something like a 4s, 4000mah, 35c will do the job, you can buy one 4s pack or 2x 2s packs and wire in parallel, one batt for either sidefor balance, inparallel you will get 8000mah, doubleruntime of one 4s pack, if you go the route of 2 packs, they have to match all numbers