Motor max amp 78 can i...

[superek4]

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!

[suicideneil]

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

[bdebde]

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.

[superek4]

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?

[superek4]

Anyone?

[suicideneil]

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...