# Battery Sources



## GooseScarer (Feb 10, 2008)

I am in need of a battery power source that will last for extended periods of time (roughly 3-8 hours). In conjunction, I was also looking for the best brands that provide low current draw in the following areas:
Brushless Motors
Steering Servos
Speed Controller

ANY help at all would be more than appreciated. Brands, websites, alternative ways of doing things.


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## gezer2u (Sep 25, 2001)

It would help if we knew what you will be using in. A quick answer is: I suppose a Lipo would be the best. Cost is more then say a nickel metal hydride. But the lipo weighs less if thats a factor. 
MaxAmp sells both types of batteries. 

I'm sure others will have more info after you tell us what its for.


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## GooseScarer (Feb 10, 2008)

I am part of a senior design team at Marquette University designing a robot that patrols a target area. The design we have is to modify a high torque RC truck (we chose the Traxxas Emaxx) and modify it to have low current components. However i keep running into problems, because it seems that RC market is designed for more current/power (understandably so) and i want to do the opposite, and decrease the current draw from the motor/steering servo/and speed controller. 

Another question is how compatible are crossovers from say if i used a speed controller that is designed for RC airplanes? Thanks again for the help.


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## hopper (Oct 12, 2006)

GooseScarer said:


> I am part of a senior design team at Marquette University designing a robot that patrols a target area. The design we have is to modify a high torque RC truck (we chose the Traxxas Emaxx) and modify it to have low current components. However i keep running into problems, because it seems that RC market is designed for more current/power (understandably so) and i want to do the opposite, and decrease the current draw from the motor/steering servo/and speed controller.
> 
> Another question is how compatible are crossovers from say if i used a speed controller that is designed for RC airplanes? Thanks again for the help.



Airplane speed controls do not have brakes, if that is an issue.


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## hankster (Jan 1, 1998)

Your best bet may be one of the Novak rockcrawler brushless motors. They are low RPM high torque designs that should draw less current. The high torque design also means you can use lower voltages... lower voltage generally means lower amp draw. The 21.5 motor might be best

http://teamnovak.com/products/brushless/3419_crawler_sintered_motor/index.html

Get the highest mAh rated LiPo battery you can find. LiPo is much lighter then NiMh cells. You can also hook a number of them up in parallel to get more "run time".

Strip the vehicle down to be as light as possible. Even taking off one shock per side would help. You can get heavier springs for the remaining shock if needed to keep the ground clearance.

Heck, call Charlie up at Novak, explain to them what it's for, they would know best.... might even have something "in the back room" that would be better then is normally available  They are good guys - 1-949-833-8873


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## 420 Tech R/C (Sep 15, 2006)

if you run some li-pos in paralell you can get almost limitless mah of capacity depending on the weight restrictions( 4- 7.4v 5000mah lipos ran in paralell= [email protected],000 mah). Which since you are using an e-maxx there is plenty of room and capacity to carry weight especially if you under gear it to death to reduce the load on the motor.another option to decrease the load on the drive train would be to use smaller OD tires. I dont know what you need for terrain handling ability, but traxxas makes 1/10 truck tires with hex drive rims that could easily be adapted to work on the maxx(rear wheels for rustler, jato)combined with a 21.5 BL with 20,000 mah on an under geared e-maxx in low gear the load to weight ratio on the motor should be minimal which would equal super long run times since brushless stuff under a minimal load runs FOREVER in comparison to brushed motor systems.


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## trailranger (Feb 9, 2006)

Besides batteries, http://rc-monster.com/ has some E-maxx mods that may improve your e-maxx for the patrols.


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