Mamba Max 7700Kv

Old 08-02-2009, 02:25 PM
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Originally Posted by jmcvicker View Post
2200 KV is the unloaded spin rate per volt. Some motors have different wattage ratings. If a motor has a higher wattage rating - you can "gear it up" and go faster. Speed is effectively horsepower delivered to the road. Wattage is a unit of work - same as horsepower. So, higher wattage - able to drive a higher gear = faster.

A 2200KV motor that is rated 1000W and a 1100W motor - the 1100W (watts) will be more powerful. Those are usually the longer motors (ie. Medusa 3680 vs. a 3670 - 80mm is longer than 70mm).

To deliver that wattage, you need volts x amps. You must be able to deliver the motor's wattage rating based on batteries hooked up. If you use a 4S lipo, that is 14.8 volts. 1100W motor. Divide 1100 / 14.8v = 74Amps. If you have a 4S1P 14.8v 5000mAh battery rated at 20C continuous, that can deliver up to 100 Amps. That would work. But if your motor is rated 1800Watts - that needs 121 Amps (or a higher Cell-count battery like 6S1P).
That helped me out thenks for the info!
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Old 08-02-2009, 03:54 PM
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Originally Posted by davidg01234 View Post
I dont really know what your talking about

but will this battery work for the Mamba monster 2200kv
http://www.hobbycity.com/hobbycity/s...idProduct=8588
It's ok - there was a lot of stuff in there that some day you'll learn. Yes - that battery is fine for the 2200. I am charging the 3S1P version of that right now. You may not get 20 minutes on that battery - but it'll be close if you take care of it. Hobbycity sells a good batch of Lipo Chargers - you can charge that one you showed there with their Accucell-6 or other similar chargers. Balance-charge at 4A or so and you'll run well.

Warning though - don't overgear things too badly for top-speed runs. You should note that high speed bashing may lead to excess heat in the motor or battery. Just get a temp. gauge and make sure battery stays below 130*F and motor below 165*F at the end of a run. My battery hit 140*F last week and it's still fine but I'm a little bit worried about it and will watch it closely next week.
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Old 08-02-2009, 04:05 PM
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Originally Posted by jmcvicker View Post
It's ok - there was a lot of stuff in there that some day you'll learn. Yes - that battery is fine for the 2200. I am charging the 3S1P version of that right now. You may not get 20 minutes on that battery - but it'll be close if you take care of it. Hobbycity sells a good batch of Lipo Chargers - you can charge that one you showed there with their Accucell-6 or other similar chargers. Balance-charge at 4A or so and you'll run well.

Warning though - don't overgear things too badly for top-speed runs. You should note that high speed bashing may lead to excess heat in the motor or battery. Just get a temp. gauge and make sure battery stays below 130*F and motor below 165*F at the end of a run. My battery hit 140*F last week and it's still fine but I'm a little bit worried about it and will watch it closely next week.
Can i charge it at 7 amps for a faster charge
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Old 08-02-2009, 04:16 PM
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Originally Posted by davidg01234 View Post
Can i charge it at 7 amps for a faster charge
Depends if the charger's wattage output supports it. It is not recommended to go above 1C for charge rate, though. That is 5A for a 5000mAh battery. You can go higher - but you may shorten the lifespan of a battery.

To charge a 14.8v battery at 5A - your charger needs to output 74 watts. The Accucel-6 (cheaper one at HobbyCity) has a 50 watt output. So, no a 4S1P battery would only be chargeable on the lower-cost one at 3.5A. You'd want to look at the 150Watt charger for higher charging rates.

After a run - you would want to let the batteries cool a little bit - back to ambient temperature (that means room temperature). So, if you finish at 120*F on the batteries, they drop back to 90*F outside in maybe 20-minutes. Then, you can start charging again. Sure, you can start charging before it cools - but again - it's thinking of how we can help you keep your parts longer before they wear out (and batteries do wear out through moderate to severe abuse at times).
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Old 08-02-2009, 04:28 PM
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Originally Posted by jmcvicker View Post
Depends if the charger's wattage output supports it. It is not recommended to go above 1C for charge rate, though. That is 5A for a 5000mAh battery. You can go higher - but you may shorten the lifespan of a battery.

To charge a 14.8v battery at 5A - your charger needs to output 74 watts. The Accucel-6 (cheaper one at HobbyCity) has a 50 watt output. So, no a 4S1P battery would only be chargeable on the lower-cost one at 3.5A. You'd want to look at the 150Watt charger for higher charging rates.

After a run - you would want to let the batteries cool a little bit - back to ambient temperature (that means room temperature). So, if you finish at 120*F on the batteries, they drop back to 90*F outside in maybe 20-minutes. Then, you can start charging again. Sure, you can start charging before it cools - but again - it's thinking of how we can help you keep your parts longer before they wear out (and batteries do wear out through moderate to severe abuse at times).
This one here should charge a 14.8 volt battery right?
http://www.hobbycity.com/hobbycity/s...idProduct=7523

So i should wait for the batterys to cool before i charge them, but does the motor and ESC need to as well or can i put another battery in it and keep goin?

WOW i didnt know electrics can so complicated, nitros are simple, but the damn neighbors are getting mad so i have to learn everything i need to know about electrics before i get one, and thanks to the people at RCTECH i know just about eveything i need to know.
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Old 08-02-2009, 04:47 PM
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Originally Posted by davidg01234 View Post
This one here should charge a 14.8 volt battery right?
http://www.hobbycity.com/hobbycity/s...idProduct=7523

So i should wait for the batterys to cool before i charge them, but does the motor and ESC need to as well or can i put another battery in it and keep goin?

WOW i didnt know electrics can so complicated, nitros are simple, but the damn neighbors are getting mad so i have to learn everything i need to know about electrics before i get one, and thanks to the people at RCTECH i know just about eveything i need to know.
Yes, that charger would do great. I like that one and would get it if one of my lower-output Accucell-6 fails.

Motor and Esc should be cool or you risk lower life-span. I mean if you run a whole pack through and the motor is 150*F - it's fine, keep going. But if it is 200*F then something may be wrong - either too high a gear or too much traction (yes - too much, like on grass). Don't run a lot on grass (tip of the day). Heat in a motor above 180*F or so helps to demagnetize the magnet at the core of the motor (shaft has a magnet on it for brushless). If you demagnetize the magnet to some degree, it'll just be harder to go fast and end up heating up faster. Nice thing about brushless is you can replace the magnet with a new shaft for not too much money if that happens. Not sure if the Castle motor has replacements but Novak sells them for their 10th scale motors.

I can't drive pack after pack. I don't have a track nearby or the patience. I like to tinker (change gearing, check bearings, help others marshall, etc). But there are some guys who live near tracks who can do it (good for growing their skills). One of the better racers I have seen racing near here has a track at his house.
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Old 08-02-2009, 06:57 PM
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how can driving on the grass heat the motor up quicker?

If you put a custom fan on the motor, you should be able to keep he temps down right
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