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-   -   Amp draw on a 8xl ? (https://www.rc-monster.com/forum/showthread.php?t=7976)

speedy 10.04.2007 02:00 PM

Amp draw on a 8xl ?
 
Hi !

How many amps will a wanderer 8xl pull in a 1/8 buggy on 4s lipo and 13/46 gearing ?

Finnster 10.04.2007 03:08 PM

No more than 120A, but how much less really depends. I wouldn't plan for under 100A tho if properly geared.

BrianG 10.04.2007 03:10 PM

It's really hard to say. There are other factors that affect amp draw like weight, drive style, etc. I would recommend looking at a similar setup in the runtime thread, calculate the average amp draw by dividing the Ah rating of the battery used by the runtime, and then multiplying that number by 6 or 7 to get a decent estimate of the burst current draw. It's not very scientific, but seems to be a fairly good rule of thumb.

zeropointbug 10.04.2007 06:38 PM

Yeah, I think it's only capable of drawing "up to" 120 amps... but like BrianG said, it can be less, and WILL be less if geared for lower speed, vehicle weight, and driving style, etc.

I know my 7XL only drew a MAX of 135amps, I could not get it to suck any more than that.

speedy 10.05.2007 02:48 AM

ok ! :)

But what's the lightes lipopack i can use with my 8xl motor ? (maxamps pack's !!! ) I have 2x2s 8000mah packs now but they are so heavy :( 750grams and the components on the motor side f the chassis only weighs like 500g som the weight will be uneven on the left and right side of the chassis and i asume that will affect the handeling badly right ?

Finnster 10.05.2007 10:54 AM

Well, again that depends on a few things. Are you racing or just bashing about?

If you are racing, you will want to buy the smallest batt that will have enough energy to last the race + ~20% or so. Say for a 15 min race, I wouldn't go any lower than a 4000mah, but exactly how much you need will depend on alot as well. if you are racing now, how much mah you put back in a pack after the race? From there find a bat that has a high enough "C" rating. Note that they are rated for continous, and burst discharges will be higher (which the 100-120A peaks would be.) Don't go too low on the C, but don't feel you have to get a batt that will do 120A continous. A 20C 4000mah would work I would think. Get someting that does at least 80A continuous to be safe (and if you have more money, get the highest C you want to spend for, like 30C.)

If the motor an all weighs ~500g, I would shoot for a batt that is somewhere close, hopefully slightly lighter, like 400-500g. Trackpower, NeuEnergy, Thunderpower, others all have quality high-end batts if that is what you are really shooting for. Maxamps or TrueRcs smaller batts will also work if $ is a bit tighter. May have to go up a bit in mah to get the discharge you need tho, like a 5000 mah batt. I know TrueRc has a 5000 mah batt that does ~115a burst, and weighs 110g/cell (so 4S=~450g) and is only $90. At that price you could have a few for several heats of racing. Don't be shocked by the lowly 10C rating, as their cells are frequently underrated, which is a nice change.


If you are just bashing, don't worry too much about it imo. If the car drives ok, flys straight, go with whatever you want to spend


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