RCCrawler Forums

toyotatrucks83 · 12-10-2011, 06:45 AM

I'm buying batteries and this brings me to an important question. How many amps does a 27T and or 55T brushed motor pull?
The batteries I need to purchase are for a cc-01 that will run the stock set up and then possibly a rooster crawler set up with a 55t motor. I'm looking at 2200mah 2s 20c lipos. I worry the 20c is too low but I maybe just neurotic.

My LCC has a Goat 3 with a 21t brushless motor. It runs 1300mah 3s 25c batteries. It he batteries never get warm. But it is a crawler.

My MRC has the mongoose system and runs 800mha 2s 20c with no problems. Even 450mah 3s 25c with no warmth. And sometimes that is at mostly full throttle with my boy driving.

My 4wheel drive 1/10 buggy has a 3000kv 2848 brushless motor and I've even run it on a 1550mah 2s 25c lipo with no battery heat issues.

So I don't have any brushed motor experience and I don't know how they will treat a lipo under trail driving conditions. Obviously I'm not looking for race/competion quality stuff. Just want to play without catching stuff on fire.

1rcmonster · 12-10-2011, 06:48 AM

In my trail trucks I run a 20c 5200mah 2s pack. Have never had a problem with them getting warm running anywhere from 27t to 55t motors.

toyotatrucks83 · 12-10-2011, 07:13 AM

5200mah at 20c has 104amp constant draw rating.
2200mah at 20c has 44amp constant draw rating.
They never talk about constant amp draw rating with nimh batteries and I don't know if that is because it doesn't apply. But most nimh batteries are in the 1800-2500mah range for factory set ups. Because of this I would guess that a 2200mha lipo would be sufficient for a factory set up. I want the 2200mah battery because they are small and cheap.
I do have some 4000mah 25c 2s I could run in this cc-01 if I have too. I just don't want to have to make chassis mods to do so.

cartronicshn · 12-10-2011, 08:01 AM

I have ran 2200 mah 20c 2s & 3s lipo on both my cc-01, one is set up with a gd-600 and a og revolver outrunner and the other one has a 55t motor in it, i haven't had any batt issues so far.

Charlie-III · 12-10-2011, 08:09 AM

OK, lets back up a little bit.

1-Mostly due to gearing, crawler motors draw very little in the way of amps, in the cc-01, not a ton more unless you gear very tall (motor will get really warm).
2-You CAN'T over amp a motor, it will draw what it needs within the limitation of the ESC, wire size and battery. It is possible to overdraw the ESC though from hard running, too low a turn on the motor, running multiple motors on a single ESC, etc.
3-If you get a battery with a large mah, you can get away with a smaller "C", is you get a battery with a small mah, you REALLY want a higher "C". The "punch" you get from a pack is due to a combination of mah & "C" rating. NiMH & NiCD have a decent initial punch (if you peaked them to "warm" just before a race) but it tapered off quickly.

A 2200mah pack is still sorta large. I run a 1300mah 35C pack in my 2.2 MOA comp rig, it's sorta big but I can do 2 courses with it.

Hope this answers your questions, if not, post back.

toyotatrucks83 · 12-10-2011, 11:53 AM

Thanks cartronicshn. Good to see someone is running 2200mah with a small c rating in a cc-01 without problems.

Charlie, your info is useful. I hope it helps some guys that are not understanding motor/ESC amp draw.

I'm not looking for punch and power. I just want to make sure a 540 sized brushed motor will not over draw and over heat a small lipo.

Charlie-III · 12-10-2011, 01:13 PM

If in doubt, through in a Tamiya connector to limit current flow!

Sorry, I just had to.

Typically, if you try to "overdraw" a pack, the motor performance will suck but not hurt the pack. You may end up heating up wires, motor or ESC, but the battery is usually fine.

If nothing else, on LiPO, be conservative and set the LiPO cutoff a little higher to prevent overdrawing a single cell.

As to a "low C rating", on a 2200mah pack it is starting to get moot. The mah rating is getting large enough to overcome the "C" rating.

toyotatrucks83 · 12-10-2011, 03:20 PM

Cool. thanks charlie. I figured with batteries 2000mha and more that I should be pretty good as long as I dont try to run a supper fast motor and run in at full throttle up and down the street.

Meatwad · 12-10-2011, 03:47 PM

Getting a pack that can handle the max continous draw of your chosen esc is an overly safe bet. However with a highish turn brushed motor thats geared lowish for a typical trail truck, it should be ok going a lil lower in amp draw.

Novak's site says 400amps forward (lol) for the rooster crawler. I'm thinking somewhere around 60-80 amps should be ok.

madkawi650 · 12-10-2011, 04:33 PM

Here's one way to look at it.. In my trail truck I run a Wraith system which is an AE-2 with a 20t brushed motor. I use 2200 mah 20 batteries. I get well over an hour of trail running.
2200 mah is 2.2 amp/hours which means 7.4 volts can be drawn at 2.2 amps for a period of one hour. So, if I get an hour of runtime I must be averaging a 2.2 amp draw.
If I was to draw the peak of 44amps ( 2200mah times 20c) the pack would be dead in 3 minutes..

Sent from my highly abused iPhone using Tapatalk

toyotatrucks83 · 12-10-2011, 07:22 PM

Wow! An hour on a 2200mah lipo in a wraith with a 20t motor. This is why I was asking. On paper it looks like I need a 5000mha 65c lipo just to be safe. But I know there is a real world with real people who can tell me if their low c rated lipos have given them trouble. Thanks for the real world data. 2200mah 20c batteries for my cc-01 are on the way.

Meatwad · 12-10-2011, 07:27 PM

Quote:

Originally Posted by toyotatrucks83

Wow! An hour on a 2200mah lipo in a wraith with a 20t motor. This is why I was asking. On paper it looks like I need a 5000mha 65c lipo just to be safe. But I know there is a real world with real people who can tell me if their low c rated lipos have given them trouble. Thanks for the real world data. 2200mah 20c batteries for my cc-01 are on the way.

Whoa, if you need 325 amps in a 1/10 crawler you're either crazy or have some type of seriously over powered setup. I'm running 5000mah/30c and its overkill for a scaler, even with a mmp/pro4 and summit tranny.

Charlie-III · 12-10-2011, 09:12 PM

Quote:

Originally Posted by toyotatrucks83

Wow! An hour on a 2200mah lipo in a wraith with a 20t motor. This is why I was asking. On paper it looks like I need a 5000mha 65c lipo just to be safe. But I know there is a real world with real people who can tell me if their low c rated lipos have given them trouble. Thanks for the real world data. 2200mah 20c batteries for my cc-01 are on the way.

Ummm.....for about the 4th time, you only need a high "C" rating when you run small mah packs.

Since "power available" is a function of "C" AND mah, big mah packs can get away with lower "C" packs, small mah packs NEED a higher "C".

[I really feel like I'm repeating myself here.........]

toyotatrucks83 · 12-10-2011, 09:32 PM

Charlie. Stop repeating yourself. I read and understood your posts. If you read I said I have some 2200mah 20c batteries on the way. Meaning I understand what everyone is saying here.
The only reason I was asking about this stuff is because I can not find the amp draw of a brushed motor. In brushless motors they write it right in the description. And with brushed escs have max loads of 400amps, which is a burst current I know, and such I thought I'd ask some guys opinions on here. (this is were the comment about needing a 5000mah 65c lipo was in reference too. Sarcasm)

squatch71 · 12-10-2011, 09:40 PM

in my CC01, running a 60T motor, 16T pinion, I have puffed my 2S 2800 20C battery....just sayin Never pick up anything smaller than 30C now...high mAh or not.

Charlie-III · 12-11-2011, 08:29 AM

Quote:

Originally Posted by toyotatrucks83

Charlie. Stop repeating yourself. I read and understood your posts. If you read I said I have some 2200mah 20c batteries on the way. Meaning I understand what everyone is saying here.
The only reason I was asking about this stuff is because I can not find the amp draw of a brushed motor. In brushless motors they write it right in the description. And with brushed escs have max loads of 400amps, which is a burst current I know, and such I thought I'd ask some guys opinions on here. (this is were the comment about needing a 5000mah 65c lipo was in reference too. Sarcasm)

My bad....

.
I somehow missed where you stated you had them ordered, it sounded like you were still not convinced.

You will enjoy it, sorry for my post.

toyotatrucks83 · 12-11-2011, 08:45 AM

No biggy Charlie. I just didn't want you think I was not understanding.

Squatch, what do you mean by "puffed"? Thanks for the heads up on the 30c. Since I already ordered some 20c I'm going to give them a try. I'll just go easy on them to start. They are cheap anyways.

Charlie-III · 12-11-2011, 09:08 AM

Quote:

Originally Posted by toyotatrucks83

No biggy Charlie. I just didn't want you think I was not understanding.

Squatch, what do you mean by "puffed"? Thanks for the heads up on the 30c. Since I already ordered some 20c I'm going to give them a try. I'll just go easy on them to start. They are cheap anyways.

"Puffed" means just that, the pack gets bigger. This also means, you are playing with a timebomb.
Running a pack too low, overcharging, etc can make a pack puff. Once puffed, ditching that cell (or the whole pack) is advised.

squatch71 · 12-11-2011, 04:17 PM

you can also puff a pack by over drawing what the battery is able to allow, amperage wise....like when I was first learning about lipos...I put a 3S 2000 25C on a 5700Kv motor....made the battery so big I couldn't get it out of my slash......

yeah, they are time bombs....best to get rid of them once they puff

ohh, have I puffed a pack while crawling? yes, 2800 mAh 2S, 20C on a 35t motor...was binding the wheels pretty good....didn't think anything of it....till I took off the body.

madkawi650 · 12-11-2011, 07:55 PM

Quote:

Originally Posted by toyotatrucks83

Wow! An hour on a 2200mah lipo in a wraith with a 20t motor. This is why I was asking. On paper it looks like I need a 5000mha 65c lipo just to be safe. But I know there is a real world with real people who can tell me if their low c rated lipos have given them trouble. Thanks for the real world data. 2200mah 20c batteries for my cc-01 are on the way.

Mines not in a Wraith.. I said I have a Wraith system.. The ESC and motor 20t out of a wraith is in my scx10 honcho.. I run a 3s 3300mah 25-50c Nanotec turnigy lipo in my Wraith with a castle sv2 and a Traxxas 21t 550 EMaxx motor .. I get almost an hour of trailing with it. Geared 18/87..

Sent from my highly abused iPhone using Tapatalk

12-10-2011, 06:45 AM	#1
toyotatrucks83 Rock Crawler Join Date: Oct 2010 Location: Reno Posts: 646	Trail truck brushed motor amps? I'm buying batteries and this brings me to an important question. How many amps does a 27T and or 55T brushed motor pull? The batteries I need to purchase are for a cc-01 that will run the stock set up and then possibly a rooster crawler set up with a 55t motor. I'm looking at 2200mah 2s 20c lipos. I worry the 20c is too low but I maybe just neurotic. My LCC has a Goat 3 with a 21t brushless motor. It runs 1300mah 3s 25c batteries. It he batteries never get warm. But it is a crawler. My MRC has the mongoose system and runs 800mha 2s 20c with no problems. Even 450mah 3s 25c with no warmth. And sometimes that is at mostly full throttle with my boy driving. My 4wheel drive 1/10 buggy has a 3000kv 2848 brushless motor and I've even run it on a 1550mah 2s 25c lipo with no battery heat issues. So I don't have any brushed motor experience and I don't know how they will treat a lipo under trail driving conditions. Obviously I'm not looking for race/competion quality stuff. Just want to play without catching stuff on fire. Last edited by toyotatrucks83; 12-10-2011 at 06:47 AM. Reason: Missing a word

12-10-2011, 03:47 PM	#9
Meatwad I wanna be Dave Join Date: Jul 2009 Location: Rancho Relaxo. California. USA. Earth. Posts: 3,292	Getting a pack that can handle the max continous draw of your chosen esc is an overly safe bet. However with a highish turn brushed motor thats geared lowish for a typical trail truck, it should be ok going a lil lower in amp draw. Novak's site says 400amps forward (lol) for the rooster crawler. I'm thinking somewhere around 60-80 amps should be ok. Last edited by Meatwad; 12-10-2011 at 03:50 PM.

12-11-2011, 04:17 PM	#19
squatch71 I wanna be Dave Join Date: Sep 2008 Location: four o six Posts: 2,101	you can also puff a pack by over drawing what the battery is able to allow, amperage wise....like when I was first learning about lipos...I put a 3S 2000 25C on a 5700Kv motor....made the battery so big I couldn't get it out of my slash...... yeah, they are time bombs....best to get rid of them once they puff ohh, have I puffed a pack while crawling? yes, 2800 mAh 2S, 20C on a 35t motor...was binding the wheels pretty good....didn't think anything of it....till I took off the body. Last edited by squatch71; 12-11-2011 at 04:19 PM.

12-10-2011, 06:48 AM	#2
1rcmonster Rock Crawler Join Date: Jan 2008 Location: Eveleth Posts: 713	In my trail trucks I run a 20c 5200mah 2s pack. Have never had a problem with them getting warm running anywhere from 27t to 55t motors.

12-10-2011, 07:13 AM	#3
toyotatrucks83 Rock Crawler Join Date: Oct 2010 Location: Reno Posts: 646	5200mah at 20c has 104amp constant draw rating. 2200mah at 20c has 44amp constant draw rating. They never talk about constant amp draw rating with nimh batteries and I don't know if that is because it doesn't apply. But most nimh batteries are in the 1800-2500mah range for factory set ups. Because of this I would guess that a 2200mha lipo would be sufficient for a factory set up. I want the 2200mah battery because they are small and cheap. I do have some 4000mah 25c 2s I could run in this cc-01 if I have too. I just don't want to have to make chassis mods to do so.

12-10-2011, 08:01 AM	#4
cartronicshn I wanna be Dave Join Date: May 2006 Location: HONDURAS...ROCK HEAVEN Posts: 5,076	I have ran 2200 mah 20c 2s & 3s lipo on both my cc-01, one is set up with a gd-600 and a og revolver outrunner and the other one has a 55t motor in it, i haven't had any batt issues so far.

12-10-2011, 08:09 AM	#5
Charlie-III I wanna be Dave Join Date: Nov 2010 Location: 07456 N. NJ USofA Posts: 8,314	OK, lets back up a little bit. 1-Mostly due to gearing, crawler motors draw very little in the way of amps, in the cc-01, not a ton more unless you gear very tall (motor will get really warm). 2-You CAN'T over amp a motor, it will draw what it needs within the limitation of the ESC, wire size and battery. It is possible to overdraw the ESC though from hard running, too low a turn on the motor, running multiple motors on a single ESC, etc. 3-If you get a battery with a large mah, you can get away with a smaller "C", is you get a battery with a small mah, you REALLY want a higher "C". The "punch" you get from a pack is due to a combination of mah & "C" rating. NiMH & NiCD have a decent initial punch (if you peaked them to "warm" just before a race) but it tapered off quickly. A 2200mah pack is still sorta large. I run a 1300mah 35C pack in my 2.2 MOA comp rig, it's sorta big but I can do 2 courses with it. Hope this answers your questions, if not, post back.

12-10-2011, 11:53 AM	#6
toyotatrucks83 Rock Crawler Join Date: Oct 2010 Location: Reno Posts: 646	Thanks cartronicshn. Good to see someone is running 2200mah with a small c rating in a cc-01 without problems. Charlie, your info is useful. I hope it helps some guys that are not understanding motor/ESC amp draw. I'm not looking for punch and power. I just want to make sure a 540 sized brushed motor will not over draw and over heat a small lipo.

12-10-2011, 01:13 PM	#7
Charlie-III I wanna be Dave Join Date: Nov 2010 Location: 07456 N. NJ USofA Posts: 8,314	If in doubt, through in a Tamiya connector to limit current flow! Sorry, I just had to. Typically, if you try to "overdraw" a pack, the motor performance will suck but not hurt the pack. You may end up heating up wires, motor or ESC, but the battery is usually fine. If nothing else, on LiPO, be conservative and set the LiPO cutoff a little higher to prevent overdrawing a single cell. As to a "low C rating", on a 2200mah pack it is starting to get moot. The mah rating is getting large enough to overcome the "C" rating.

12-10-2011, 03:20 PM	#8
toyotatrucks83 Rock Crawler Join Date: Oct 2010 Location: Reno Posts: 646	Cool. thanks charlie. I figured with batteries 2000mha and more that I should be pretty good as long as I dont try to run a supper fast motor and run in at full throttle up and down the street.

12-10-2011, 04:33 PM	#10
madkawi650 Rock Crawler Join Date: Oct 2010 Location: Chezzetcook Nova Scotia Posts: 537	Here's one way to look at it.. In my trail truck I run a Wraith system which is an AE-2 with a 20t brushed motor. I use 2200 mah 20 batteries. I get well over an hour of trail running. 2200 mah is 2.2 amp/hours which means 7.4 volts can be drawn at 2.2 amps for a period of one hour. So, if I get an hour of runtime I must be averaging a 2.2 amp draw. If I was to draw the peak of 44amps ( 2200mah times 20c) the pack would be dead in 3 minutes.. Sent from my highly abused iPhone using Tapatalk

12-10-2011, 07:22 PM	#11
toyotatrucks83 Rock Crawler Join Date: Oct 2010 Location: Reno Posts: 646	Wow! An hour on a 2200mah lipo in a wraith with a 20t motor. This is why I was asking. On paper it looks like I need a 5000mha 65c lipo just to be safe. But I know there is a real world with real people who can tell me if their low c rated lipos have given them trouble. Thanks for the real world data. 2200mah 20c batteries for my cc-01 are on the way.

12-10-2011, 09:32 PM	#14
toyotatrucks83 Rock Crawler Join Date: Oct 2010 Location: Reno Posts: 646	Charlie. Stop repeating yourself. I read and understood your posts. If you read I said I have some 2200mah 20c batteries on the way. Meaning I understand what everyone is saying here. The only reason I was asking about this stuff is because I can not find the amp draw of a brushed motor. In brushless motors they write it right in the description. And with brushed escs have max loads of 400amps, which is a burst current I know, and such I thought I'd ask some guys opinions on here. (this is were the comment about needing a 5000mah 65c lipo was in reference too. Sarcasm)

Sponsored Links

12-10-2011, 09:40 PM	#15
squatch71 I wanna be Dave Join Date: Sep 2008 Location: four o six Posts: 2,101	in my CC01, running a 60T motor, 16T pinion, I have puffed my 2S 2800 20C battery....just sayin Never pick up anything smaller than 30C now...high mAh or not.

12-11-2011, 08:45 AM	#17
toyotatrucks83 Rock Crawler Join Date: Oct 2010 Location: Reno Posts: 646	No biggy Charlie. I just didn't want you think I was not understanding. Squatch, what do you mean by "puffed"? Thanks for the heads up on the 30c. Since I already ordered some 20c I'm going to give them a try. I'll just go easy on them to start. They are cheap anyways.

RCCrawler Forums

Thread: Trail truck brushed motor amps?