What capacity lipo for 2wd racing?

[Peter_B]

So I'm looking at shorty lipos to get for my Cougar KF2 SE.

Looking at getting a couple of packs of either of these (or similar)...

https://www.modelsport.co.uk/centro-2s-5000mah-7-4v-100c-hard-case-shorty-lipo-battery/rc-car-products/422729

https://www.modelsport.co.uk/absima-low-profile-shorty-lipo-7-4v-110c-3800-mah/rc-car-products/407627

What capacity should I go for?

The 5000mah will likely be heavier, but I've read of people adding weight under the batteries in a KF2SE so maybe it wouldn't be an issue. Also the 5000's wouldn't need charging as often - might get practice and a race, or 2 races, out of 1 charge.

I think the club runs 5-6 min races and I'll be running motors between 13.5T and 6.5T. Not sure how many races per night, maybe 3-4 plus a final at a guess.

Also, has anybody any experience of Centro batteries? I've not heard of them.

[Jonathon Gillham]

I charge mine between every race and my 2wd are usually around 8v still after a 6min race, so you could get a few races out of a charge. I run 5000mah shorties but 17.5T.

The 3800mah will work too, some people here run around 2500mah rx type packs as they get through a race but its heaps lighter.

I just have 1 battery per car too 

[Peter_B]

I've gone for the 5000mah packs. I don't know how much time there would be for charging between races. Friday night meets racing is from 7 to about 10 I think, so I'd imagine races come around quite quickly even if only running 2wd.

I've gone for 2 packs, just in case. Thinking I can go with 2 charged packs, use one for practice then it can go on the charger to top up whilst I use the other for a race (or two). Then back to the first pack for the next race(s).

It sounds like a plan to me

[Wooders28]

A bit late for a reply, but i went for the lighter still absima 3200, enough juice for a race and not far off storage charge at the end, so i didnt end up with the pain that is storage charging a half charged lipo.

Light weight, means you can put extra weight were its needed, forward, rearwards etc.

If you go for the low grip set up,  the bottom belt is lifted over the lipo, with a roller (bearing), so it can only be lifted so far before it hits the upper belt, meaning limited room for the lipo.

[Peter_B]

Ah. Didn't think of that.

I'm sure that if a certain size shorty was required it would say so somewhere. I haven't found anything like that...yet.

I guess I'll see when I get it all together. At least there are options for putting the lipo in front of the motor if I have to.

[Wooders28]

Also, with the low grip, i found although the turnigy nano tech shorty would fit, the sides of the chassis meant i couldnt get the angle to slide it in, so either had to unbolt the side pod, or take a grinder to it 🙄😀

[Peter_B]

31 minutes ago, Wooders28 said:

Also, with the low grip, i found although the turnigy nano tech shorty would fit, the sides of the chassis meant i couldnt get the angle to slide it in, so either had to unbolt the side pod, or take a grinder to it 🙄😀

I have read about having to trim the side pod a bit.

I think it's going to be fun finding out when I build the car.

[Wooders28]

11 minutes ago, Peter_B said:

I have read about having to trim the side pod a bit.

I think it's going to be fun finding out when I build the car.

Dont need to with the absima 3200,they are thin enough to just slide in. But the sides arent expensive anyway.

[Losi XXT-CR]

Brushless setups are generally a lot more efficient and pull less amps than older brushed race motors. 

I used to run 4-5 min races in all sorts of vehciles with only 2000 and 2400mAH NiMH batteries on motors as hot as 11 turn. A 3800mah 2S should last ages. Maybe even a couple of races if using a mild turn brushless motor. 

[steelo]

I use 2 Turnigy 3000 mah lipos, 1 for practice and the other for racing. The races are around 10 minutes long and have yet to experience any alarms or power issues....heck, I might be able to get 2 races out of 1 pack...maybe... 

 

I'm running a 13.5T brushless motor in a 4wd re re Optima and opted for a smaller capacity, lighter lipo since the chassis is already pretty heavy. Surprisingly, it holds its own though against much more modern buggies in an amateur class =)