Batteries 4S 2650 MAmp batter vs 3S

N4RF

New Member
Ijust got my hands on a 4S 2650M battery and have been told its too large for a plane that is expecting a 3S. The plane is an Horizon Pulse 15e with a 40Amp ESC and a B15BL Outrunner motor 880KV.

If this truly is too large a battery then what may be my options.

I actually came across this site after watching a Youtube video done by the site that discussed the size requirements. It didn't mention that extra size would be bad, just that it would help all that much.

I'm relatively new to the hobby (1.5 years) and still struggling with the electronics side.

Thanks
 

Tony

Staff member
More than likely it's not the size or weight of the battery that is the issue, but the voltage. a 3s pack is 11.1 volts nominal whereas the 4s pack is 14.8 nominal. Or fully charged, 12.60 and 15.54 respectively. Going that much over can and will burn up ESC's and motors if they are not rated for them.

If the plane will handle that kind of voltage, then the size could also be an issue if the battery compartment is pretty small. a 4s1p pack will have an extra cell which will cause it to be larger in size as well as heavier.

What video did you watch? The Matching Motor, ESC & Battery video?
 

N4RF

New Member
Yep, I think that was the one. Posted back in 2011, I think. So, would boosting the ESC to a higher amp help? There were a number of formulas givenand I still have to run through them.

I'm sensing that I may have to sell the 4S and still with the 3Ss that I have but wanted to check option first.

- - - Updated - - -

By the way, how'd you make out in the ice? Central MD got a drizzel which still can't be driven on but will at least melt faster.
 

Tony

Staff member
Raising the amp rating will not help (not for this matter anyway). You would need to verify the max voltage for the ESC and the motor and if they are only rated for 3S, then you would have to upgrade both of them.

I would just stick with the 3S for now. Just make sure the battery that you are using can withstand the amps that the motor is pulling (per the calculations I stated in the video). Just remember, a higher MAH and Higher C rating will cause the battery pack to be larger and heavier. Mah more so than the C rating.
 

Smoggie

Well-Known Member
N4RF,

As Tony says, you would need an ESC capable of 4S operation. The standard ESC I wouldn't be happy with on 4S because it has a linear mode BEC which struggle on anything more than 3S. Other than the ESC you should be ok if you fit a slightly smaller prop to keep the amps down. The standard Pulse uses a 12x8 so you would need to go to something like a 11x6 prop. The motor should be ok on 4S as long as you prop down.

Whenever you change setup like this always test the plane with a wattmeter to make sure amps are within limits.

The battery will also weigh more which will increase the weight of the plane and possible effect the CG too, I dont have a Pulse so dont know how well it would cope with the weight.
 
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Admiral

Well-Known Member
My experiences with increasing power well above the recommended suggests that you look at the air frame as well, will it handle the extra speed and power?
I have torn wings and control surfaces off with a need for speed, now a days I fly mainly Helicopters & Quads but keep the fixed wings that I do fly close to standard.
 

rjhenry

Member
N4RF,
If it's any help I have that plane too. I use a Pulse 3300 3s and a pulse 3700 3s (they were out of the 3300 when I got the 2nd pack). The plane fly's grate on 3s with plenty of power, my timer is set for 6 min. and my packs come back at 3.8 v per cell, but you can easily get 10 or 11 min. flight times (I just like my packs to come down at storage charge but that's just me ) lol. Not sure what your goal is but you don't need 4s in that plane.
 

N4RF

New Member
Thanks, Henry. It's my first real acrobatic plane so my purpose is to learn. Flying a straight line would help ....... ;)

Ultimately, I'd love to get into pattern flying.
 

rjhenry

Member
I'm Shure you'll like the plane, just don't do what I did. It flew so nice I got a little over confident and flew a perfect 100 foot loop in 99 feet lol so I'm on my seconded one.
Oh and one other thing, the canopy "WILL" come off in flight. You need something to hold it down I use a Velcro strap about the middle of the canopy. Rubber bands work but I've seen them still come off. There's at least 5 guys at my club that have a Pulse E15's and I've seen it come off every single one, so strap it down. other than that it's a grate plane
 
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