current draw on 1512/3D?

[zeropointbug]

Hey, some of you know I just bought a 1512/3D motor from Mike (although haven't received it yet), and I was going to run 7s2p A123 pack for 6s lipo equivalent.

The truck will weight in at almost 10.5 lbs with this pack, which is kinda too heavy for my liking. So I was thinking if the 1512/3D doesn't draw more than 80 amps geared for <40mph, I could use a single 7s pack, or 1p. The truck will weight 9.3 lbs with a single 7s pack.

Do you guys think it's worth it going a single pack? A 7s2p has 100Wh of usable energy on tap, more than a 4s8000mah lipo pack. (~90Wh new)

[bdebde]

I don't have any experience with the A123's, but with that many Wh's I would think it would be fine at 1p.

[glassdoctor]

The extra pound of batteries will have an impact but it should be minimal. I would guess the amp draw would be 60-80 amp spikes on acceleration with an occasional higher blip in the 100+ range. But those spikes are literally only for like .1 seconds or so.

Normal running will should acceleration "spikes" in the 50-80 range... and those are very brief. On a full acceleration (that takes 2-3 seconds.... beyond the initial spike...) the amps drop to 40-50... and down to around 30 once at speed typically.... at least that's what I recall with my 1512/1515 setups.

I would go with a 2p setup for runtimes sake. Also 10.5lbs really isn't that bad, I would get worried if it weighed 12lbs IMO....


Bye:018:

[zeropointbug]

GD, so if you say that's what the amp draw is like with the Neu's, then 1p should be able to 'handle' it I guess. A 7s pack is going to be able to deliver 1200+ watts at 17.5 volts and 70 amps, but the voltage drop is quite significant at these current levels (after all, it's only 2300mah).

The batteries will only run cooler when the load is split across 2p, and there is the runtime aspect too.

I just went and looked at the handy 'runtime thread' and see that everyone has quite heavy trucks IMO. The average is about 12 lbs, with some 13 lbs, yikes.

Zeropointbug - I have just received my Neu 1512 2.5D and am pondering exactly the same thing as you - A123 7S 1P or 2P?

I'm keen to keep voltage high so I can keep current low - after reading about the heat issues with Quarks and other ESCs.

I hope to be up and running on at least 7S1P by next week so will post my findings here. I was thinking of making 2x4S1Ps and 2x3S1Ps for flexibility - that way I can put a 4 on one side and a 3 on the other, or a 4&3 on each side of the truck. Excessive?

zpb, are you sure about the total weight on your vehicle? I know that my truggy with the 1512 and a 4S2P 8Ah pack goes at just over 10lbs.

In anycase, the only experience I had with the A123s was running a 5S1P pack with my 9XL. The performance was OK. I would imagine that the performance for you would be better, since the current demand will be lower. I do know that the A123s got HOT running in 5S1P configuration.

Hey, give it a try. The worse thing that can happen is that you have to reconfigure the batteries.

Good luck.

Oh, what you are going to do about the Quark acting funny on that much voltage? Are the additional caps supposed to cure that?