Motor max amp 78 can i...
 

I am using a Neu 1512/2.5d max amp is 78amp, can i use a 4s 2650mah@40C lipo.

It gives me 2.6x40c=106amp compared to my usual 5x30=150amp.

for a 7-10main should be enough as my buggy consumes about 230amp per min based on my 5x30c lipo.

questions

1st. does it affect my amp draw if i use a lower mah batt?

2nd. is the 106 amp enough for race?

thxs!

78amps is the maximum continous rating of the motor, but it will pull larger peaks than that, up around 120-150 quite easily.

I wouldnt use anything less 3500-4000mah personally, regardless of the C rating- a total of 4s lipo will still only weigh roughly the same as a single 6/7 cell nimh pack, so weight shouldnt be an issue.

1. possibly. Even with a high C rating, the lower mah capacity limits the maximum amount of current the lipo can discharge; 106amps is borderline at best, upwards of 120 would be more ideal.

2. A ten minute race isnt all that long I guess, and people say a ~5000mah pack can last 20-25 minutes under racing conditions. If you know how many mah you are using with your other larger lipos, then you can calculate how many you need + a little overhead and base your next lightweight setup on that.

Thats my thinking anyway, but see what the racers around here have to say :yes:

Well, Neu's amp rating is at max volts (30v); your volts will be half that, so you could see currents that are double that (watts/your voltage).

I'm with Neil on capacity as well, I would not go much less than 4000mah for 4s; unless you like to buy batteries often.

*edit* By 230amp per min, I assume you mean 230mah per min: keep in mind that rating will go up as voltage goes down. My 6s racing buggy uses less than 200mah/min, and if to get 230mah/min. with 5s, I bet you will get well over 250mah/min. on 4s.

I see, then it doesn't make sense for me to change batt, I was thinking 4s 3000 or 4s 2650 becoz of lesser weight.

But I hv a racer who race 3s 3200mah@40c in a ve8 with 3200kv motor. He race with us 7mins n temp ok. N even faster than us. Does it mean his batt will spoil faster?

Anyone?

I wouldnt like to guess really, seems he's using a smaller & higher kv motor than a normal setup would use, but on a lower voltage; that would in theory mean higher current draw, but with a smaller motor it may work out roughly the same.

Without an Eagletree graph of a typical run its all just speculation & theory, if we could see how many amps he's pulling & how much or how little the voltage droops at the same time, then we could draw some fairly good conclusions.

As it is, lipos only last 200-300 cycles anyway, so a typical pack is only good for a couple seasons of racing I would say, hence my love of cheap zippy lipos...