RCCrawler Forums

bent70 · 07-01-2008, 09:49 AM

I am running a mm/ bm9 combo and would like to know what c rating I can get away with? I was looking at some cost effective 3s 8c lipos and was wondering if I am safe with that low of an amperage overhead. The bm9 is really no bigger than a 400 size motor...I just don't know how many amps it draws.

JohnRobHolmes · 07-01-2008, 09:52 AM

I would get a pack of at least 25a continous, but it really depends on your terrain. That little motor can burst about 55 to 60a under stall. Mostly it won't get above 15a.

bent70 · 07-01-2008, 01:06 PM

I tossed it on the watt meter with a tenergy 6cell 3800 pack still in car. I was getting 3-6 amps and from binding the tires and making the slipper slip I peaked at 17.8 amps @ 96watts.

JohnRobHolmes · 07-01-2008, 01:22 PM

The watt meter will average the current requirements over one second intervals. The higher bursts will happen in the 1/10th second range, and will not be caught by a standard wattmeter. I still recommend a pack with at least 25a continuous.

bent70 · 07-01-2008, 05:48 PM

Ok, thanks for the input.
Now my only problem is finding a lipo that will fit my dimensions..
3.5"L x 2"W x 2"H that is more than 1200mah.

Tanis · 07-01-2008, 07:07 PM

Holmes has what you need

http://holmeshobbies.com/product.php...&cat=10&page=1

bent70 · 07-01-2008, 07:47 PM

I just ordered some chinese 30c 3s 1500's...reviews looked good, but I'll see for myself. Dirt cheap and yes I know you get what you pay for, although its worth a little for experimenting.
Those are new on Holmes' site....mabey if these don't work out.

07-01-2008, 09:49 AM	#1
bent70 Pebble Pounder Join Date: May 2005 Location: san francisco Posts: 193	lipo c rating recomendation I am running a mm/ bm9 combo and would like to know what c rating I can get away with? I was looking at some cost effective 3s 8c lipos and was wondering if I am safe with that low of an amperage overhead. The bm9 is really no bigger than a 400 size motor...I just don't know how many amps it draws.

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

07-01-2008, 09:52 AM	#2
JohnRobHolmes owner, Holmes Hobbies LLC Join Date: Nov 2004 Location: Volt up! Gear down! Posts: 20,290	I would get a pack of at least 25a continous, but it really depends on your terrain. That little motor can burst about 55 to 60a under stall. Mostly it won't get above 15a.

07-01-2008, 01:06 PM	#3
bent70 Pebble Pounder Join Date: May 2005 Location: san francisco Posts: 193	I tossed it on the watt meter with a tenergy 6cell 3800 pack still in car. I was getting 3-6 amps and from binding the tires and making the slipper slip I peaked at 17.8 amps @ 96watts.

07-01-2008, 01:22 PM	#4
JohnRobHolmes owner, Holmes Hobbies LLC Join Date: Nov 2004 Location: Volt up! Gear down! Posts: 20,290	The watt meter will average the current requirements over one second intervals. The higher bursts will happen in the 1/10th second range, and will not be caught by a standard wattmeter. I still recommend a pack with at least 25a continuous.

07-01-2008, 05:48 PM	#5
bent70 Pebble Pounder Join Date: May 2005 Location: san francisco Posts: 193	Ok, thanks for the input. Now my only problem is finding a lipo that will fit my dimensions.. 3.5"L x 2"W x 2"H that is more than 1200mah.

07-01-2008, 07:07 PM	#6
Tanis Keep it real Join Date: Jun 2006 Location: Yakima,WA Posts: 6,532	Holmes has what you need http://holmeshobbies.com/product.php...&cat=10&page=1

07-01-2008, 07:47 PM	#7
bent70 Pebble Pounder Join Date: May 2005 Location: san francisco Posts: 193	I just ordered some chinese 30c 3s 1500's...reviews looked good, but I'll see for myself. Dirt cheap and yes I know you get what you pay for, although its worth a little for experimenting. Those are new on Holmes' site....mabey if these don't work out.

Sponsored Links

RCCrawler Forums

Thread: lipo c rating recomendation