estimate
 

I just need a amp estimation more or less from you oaks experience... I have a 860W Turnigy with 60A ESC... which prop size would you recommend and what type of Amps should I expect to be drawn from that prop? the reason being I need to select a battery that will at least give me that size burst current...

RE: estimate
 

If you're asking about the Turnigy 4260-600 then hobbycity suggests

Recommended props:
11x5.5 APC-E (6 cells: 41A, 870W, 2900g, 60mph, 11600rpm)
12x6 APC-E (6 cells: 54A, 1130W, 3500g, 60mph, 10800rpm)

Which sounds about right. This means at 20C max your looking for battery that is a minimum of 2050 or 2700 mah using the data above.

(41 amp * 1000 ) = 41000 mah / 20c = 2050
(54 amp * 1000 ) = 54000 mah / 20c = 2700

A 3000+ mah cell would minimize the chance of damage.

RE: estimate
 

If you look at the product page for that specific Turnigy motor on the Hobby City website, there will probably be a lot of comments under the "User Reviews" section, where people describe in detail what plane/motor/esc/prop/battery combo they have used it in, and how many amps it pulled. There is usually a lot of good information in those posts.

Good luck

RE: estimate
 

BalsaBrkr

thats awesome info and exactly what I wanted... thanks

you wouldn't happen to know the flying times also? say maybe full throttle and half throttle times when using the 11x5.5E prop? with a min 2050 20C ...

RE: estimate
 

Using the 41 amp version

Then full throttle will draw 41000 mah an hour

(41 amp * 1000 ) = 41000 mah / 20c = 2050

So a 2050 pack would last at 85% capacity utilization

(2050 * .85) / 41000 hours

or .0425 hours * 60 minutes = 2.55 minutes

and your battery will hate you...

Under normal sport flying I would anticipate a time of around 7 minutes would be safe

RE: estimate
 

thanks again... help appreciated...

RE: estimate
 

ROTFL!

Very true..

I would call 7 minutes a VERY VERY optimistic figure for that battery.

He wants something larger at that large of a draw.

I would minimally spec two batteries in Parallel if he wants to save money.

RE: estimate
 

It depends.

I fly a 500 watt 3D Hobbyshop Extra SHP on 2100 3s lipos and get 7 minutes with no problem.

At WOT it draws 43 amps having a similar profile to his setup.

Power draw is not linear with throttle, so 1/2 throttle doesn't mean 21 amps.

WOT provides extreme vertical and is seldom used for more than 10 - 15 second bursts.

RE: estimate
 

Even 10-15 second bursts sounds like a lot of "time" spent going vertical.. unless actually hovering which uses less than acceleration while going vertical. And that's (gravity) what chews up available battery power.

RE: estimate
 

You are correct, probably more like 4 - 7 seconds... Hovering is more like 2/3rds throttle.

7 seconds would be from near ground to way up for something like an extended flat spin.