Newbie questions about Nitro to Electric switch
02-06-2010, 12:07 PM
#1
Newbie questions about Nitro to Electric switch
Been debating about switching from nitro to electric in my RC8T. my main question is regarding batteries, mainly the pros and cons of Lipo batteries vs. standard NiMH batteries. Im not getting too serious about racing and my main concern is value for the money and run-time for each.
I was looking at the Mamba Monster 1/8th Scale Brushless setup so what would be the best batteries to run with that??
Also.....what else would be recommended to go with that setup besides motor, ESC and batteries??
I was looking at the Mamba Monster 1/8th Scale Brushless setup so what would be the best batteries to run with that??
Also.....what else would be recommended to go with that setup besides motor, ESC and batteries??
02-06-2010, 01:18 PM
#2
You're nor going to be competitive or happy trying to run NiMh with a MMM type setup. That pulls too many amps for NiMh if you're serious about running your RC8T. Lipo outclasses NiMH as far as amps, voltage, runtime and weight. The number of cells you would need would be weight and size prohibitive. A MMM setup would start at 4S (16.8v) or higher depenbding on the motor kv you select. You'll get 20+% more runtime from lipo that you would with NiMh and more consistent performance from lipo.
The only other thing you'd need is a good lipo capable balancing type charger.
The only other thing you'd need is a good lipo capable balancing type charger.
02-06-2010, 05:57 PM
#4
which mAH & C rating is subjective question. the C rating indicates discharge rate. the higher gives u more punch but sacrifices the run time.
my suggestion for 4S use the same battery from same 2 x 2S from manufacturer of same rating for optimum performance.
my suggestion for 4S use the same battery from same 2 x 2S from manufacturer of same rating for optimum performance.
02-07-2010, 06:02 AM
#5
Like this?..... http://www.hobbyking.com/hobbyking/s..._hardcase_pack
02-08-2010, 08:43 PM
#6
I would suggest anything over a 5000mah with a min. C rating of 30C. If the C rating is to low to support the amp draw that a brushless system can pull you will kill the batteries due to heat or create a dangerous situation due to the lipos being overworked.
I found a great deal on some 5000mah batteries that are rated at 30C on ebay. I have purchased them for the exact same setup and run two of them for a total of 14.4 nominal volts. Running two of these would give you a 4S setup!
http://cgi.ebay.com/ws/eBayISAPI.dll...=STRK:MEWAX:IT
I have had great luck with these and the price is great. I have purchased from this seller many times as well, but it will take up to 3 weeks for them to arrive.
Just always make sure you motor is not getting crazy hot and pulling crazy amps due to load or overgearing. That can cause the lipo to be overworked.
Hope this helps
I found a great deal on some 5000mah batteries that are rated at 30C on ebay. I have purchased them for the exact same setup and run two of them for a total of 14.4 nominal volts. Running two of these would give you a 4S setup!
http://cgi.ebay.com/ws/eBayISAPI.dll...=STRK:MEWAX:IT
I have had great luck with these and the price is great. I have purchased from this seller many times as well, but it will take up to 3 weeks for them to arrive.
Just always make sure you motor is not getting crazy hot and pulling crazy amps due to load or overgearing. That can cause the lipo to be overworked.
Hope this helps
02-09-2010, 08:11 AM
#7
Runtime is mainly capacity (mah) of the lipo. The C rating is the discharge capability like a 5000mah 30C lipo has a continuous discharge of 5000/1000 x 30 = 150amps. The motor is what sets the amps needed and if the lipos can't produce that currnet, they will run hot and not last long - lipos do not like to be overheated.
You want slightly more battery than your setup needs - that usually insures a cool running setup (with correct gearing). 30C should be plenty, 20C may be borderline, 15C is too little. I'd get the 30Cs.
You want slightly more battery than your setup needs - that usually insures a cool running setup (with correct gearing). 30C should be plenty, 20C may be borderline, 15C is too little. I'd get the 30Cs.
02-09-2010, 09:56 AM
#9
Correct, it is more around the ability of the batter to deliver the current. Think of it as a higher C rating is a larger pipe to deliver the power and smaller C rating smaller pipe.
When you have a demand that exceeds the C rating of the battery, you work the battery to hard and limit the power/amp draw the motor has the ability to pull form the battery.
In the case of where you have an abundant amount of C rating in a batter say 30c+ then if feels as though it gives you more bunch but in reality you are meeting the amp draw the motor requires.
In a small amp draw setup a high C rated batter will provide no addional punch verses a lower C rating that still meets the required amp draw (pipe size...)
Example going from a 30c battery to a 50c battery will offer no real benefit in a light to medium amp draw setup say under 120 - 150 amps.
Just my -98 cents worth.
Hope this helps
Hope this helps
When you have a demand that exceeds the C rating of the battery, you work the battery to hard and limit the power/amp draw the motor has the ability to pull form the battery.
In the case of where you have an abundant amount of C rating in a batter say 30c+ then if feels as though it gives you more bunch but in reality you are meeting the amp draw the motor requires.
In a small amp draw setup a high C rated batter will provide no addional punch verses a lower C rating that still meets the required amp draw (pipe size...)
Example going from a 30c battery to a 50c battery will offer no real benefit in a light to medium amp draw setup say under 120 - 150 amps.
Just my -98 cents worth.
Hope this helps
Hope this helps
02-09-2010, 10:02 AM
#10
Further Example:
Stock Traxxas Slash, I have a 4000mah 15c battery that runs great, if I install a 30c battery I really do not notice much performance gain due to the stock brushed motor cannot pull alot of amps.
Traxxas Slash VXL (Brushless System) the same 15c battery greatly limits the performance because it cannot provide a big current to support the amp draw (To small of pipe...) and heats the 15c battery up quickly due to it being overworked... However the 30c battery privided the needed amp draw and propels the vehicle much faster and does not overwork the battery. This gives the impression that the battery privided more punch but actually was just able to meet the amp draw (Pipe Size) needed for that application.
Stock Traxxas Slash, I have a 4000mah 15c battery that runs great, if I install a 30c battery I really do not notice much performance gain due to the stock brushed motor cannot pull alot of amps.
Traxxas Slash VXL (Brushless System) the same 15c battery greatly limits the performance because it cannot provide a big current to support the amp draw (To small of pipe...) and heats the 15c battery up quickly due to it being overworked... However the 30c battery privided the needed amp draw and propels the vehicle much faster and does not overwork the battery. This gives the impression that the battery privided more punch but actually was just able to meet the amp draw (Pipe Size) needed for that application.
02-10-2010, 05:47 AM
#11
OK so since I'm a total electric newbie (I've always had nitro) help me out here...... How can you run 2 2S batteries together at the same time?? Wire them together somehow? Or would I just be better off getting a 5000+ mAh 3S and call it a day?
Like I said, I'm a NOOB so help me out
Like I said, I'm a NOOB so help me out
02-10-2010, 08:02 AM
#12
They make both series and a parallel connectors. Connectinmg 2 batts in series doubles the voltage - using a pr of 2S lipos in series makes them equiv to a 4S of the same capacity (mah).
Running them in parallel doubles capacity, but keeps the voltage the same. Running a pr of 2S 5000mah lipos in parallel for example you still have a 2S combination, but now you have 10,000mah. Running in parallel is usually done to increase run time, running in series is usually for higher voltage.
My HPI Savage Flux runs a pr of lipos in series for the higher voltage - my Traxxas Moini E-Revo runs a pr of lipos in parallel for increased run time.
Running them in parallel doubles capacity, but keeps the voltage the same. Running a pr of 2S 5000mah lipos in parallel for example you still have a 2S combination, but now you have 10,000mah. Running in parallel is usually done to increase run time, running in series is usually for higher voltage.
My HPI Savage Flux runs a pr of lipos in series for the higher voltage - my Traxxas Moini E-Revo runs a pr of lipos in parallel for increased run time.
02-13-2010, 07:02 AM
#13
OK so my budget is tighter than I thought and the Novak setups are looking good for the price......any issues with these??
http://www.amainhobbies.com/product_...otor-Combo-65T
http://www.amainhobbies.com/product_...otor-Combo-65T
02-24-2010, 06:32 AM
#14
They make both series and a parallel connectors. Connectinmg 2 batts in series doubles the voltage - using a pr of 2S lipos in series makes them equiv to a 4S of the same capacity (mah).
Running them in parallel doubles capacity, but keeps the voltage the same. Running a pr of 2S 5000mah lipos in parallel for example you still have a 2S combination, but now you have 10,000mah. Running in parallel is usually done to increase run time, running in series is usually for higher voltage.
My HPI Savage Flux runs a pr of lipos in series for the higher voltage - my Traxxas Moini E-Revo runs a pr of lipos in parallel for increased run time.
Running them in parallel doubles capacity, but keeps the voltage the same. Running a pr of 2S 5000mah lipos in parallel for example you still have a 2S combination, but now you have 10,000mah. Running in parallel is usually done to increase run time, running in series is usually for higher voltage.
My HPI Savage Flux runs a pr of lipos in series for the higher voltage - my Traxxas Moini E-Revo runs a pr of lipos in parallel for increased run time.
Also was wondering if 20C would be enough for that MM setup??
02-24-2010, 08:57 AM
#15
You can do that - run two lipos in series as long as they are the same size and C rating and have about the same useage history. They should be near same voltage when you 1st connect them. You could also run a 2S and a 3S for a 5S equiv, again as long as they're the same mah and C ratings, etc.
Not sure on the 2650, but Castle orig advised 25C as a min to run the Sav Flux which is 2200kv. They've recently started saying 30C is min. This is impacted by weight - heavier the RC is, the more amps needed to get it going. Flux weights ~12lbs (no batts) if yours is similar weight, guidelines should be applicable, if you're lighter, than may be abkle to use lower C rating. I would rather be safe than sorry though. If batts aren't up to the task, it will smoke the esc.
Personally, I wouldn't use 20Cs.
Not sure on the 2650, but Castle orig advised 25C as a min to run the Sav Flux which is 2200kv. They've recently started saying 30C is min. This is impacted by weight - heavier the RC is, the more amps needed to get it going. Flux weights ~12lbs (no batts) if yours is similar weight, guidelines should be applicable, if you're lighter, than may be abkle to use lower C rating. I would rather be safe than sorry though. If batts aren't up to the task, it will smoke the esc.
Personally, I wouldn't use 20Cs.
