FMA LiPos in an E-Maxx

I love racing my E-Maxx, if you can call it that. Over the past 3 years I’ve tried nearly every hop-up and performance enhancement I could find and now it is a serious custom race machine. But one thing really weighed it down, well two things, my two 7 cell 3300 battery packs. So when I had a chance to try the new FMA Direct Scorpion LiPo packs and chargers I was ready to experience cutting edge technology!

I’d heard about LiPo before but had not tried them because of safety concerns and because I wasn’t sure a system designed for a buggy or stadium truck would work in a dual battery, high voltage E-Maxx. Thankfully FMA Direct was able to deliver a product which was both safe and works fine in the E-Maxx. I used two 7.4v 1p2s LiPo packs and the Scorpion 2s charger. These packs are about HALF the weight of my 7 cell packs so just by using them I was dropping about a pound of weight from my truck. The FMA Direct LiPos fit with no problems in my E-Maxx and they were all pre-wired. They had two leads for the Low Voltage Cutoff (LVC) - this is a safety feature which cuts off the motor temporarily if the voltage in your packs gets too low. The LVC wires normally run between the Speedo and the Receiver, in the case of a dual battery E-Maxx, the LCV wires go from the receiver to pack A, then pack A to pack B, then pack B to the speedo. The power hooks up just like regular packs, matter of fact, the FMA LiPos come pre-wired with a Deans connector so for me it was plug and play. Charging was super simple, just plug the packs into the charger and watch the lights. They ultra fast charge up to 90% and you can take them off and run them. No need to wait for full charge if you don’t need the extra capacity.

Of course the big question is how do they perform - and what about the missing 2 volts (16.8v for 14 cells vs 14.8v for the Lipos!) Well, I’m happy to say that the performance was much better than I expected. The packs had more punch than anything I’ve ever seen or used. Expecting to miss the 2 volts, I geared up a bit...when I hit the track the speed was so intense, I actually geared it back the way I was running with my 14 cell packs. No radar tests were done, I was running the truck where I always do, Xtreme RC Racetrack, but I know my truck well - and it was quicker and faster than it was on 14 cells. I know that LiPo has an amazing capacity to delivery power and I suspect that standard cells just can’t feed the big brushless motor and speedo I have like the LiPos can. On top of that, with a full pound or more of weight missing, the motor didn’t have to work as hard to get up to speed. The truck is more agile, quick, and nimble. With that weight gone, that’s also less load and strain on the drivetrain and suspension components.

Thanks to great technological breakthroughs like FMA Direct’s Scorpion LiPo packs and chargers, we get enhanced performance from the same trucks we use today. Aside from my switch to brushless, I can’t think of a single upgrade which delivers the performance gain these LiPos do. The technology and capacity have reached a point were consumers can really reap the benefits without any extra effort or work.

I know lack of understanding held me back from trying LiPo. Now that I have, I want to let everyone know how great, easy and safe it is. If I can answer any questions, please feel free to post them here.

Thanks, and see you at the race track!

David Maffucci
(MacII)

Here you can see how much smaller the LiPo Pack is than the standard 7 cell pack.



A photo of the chargers and packs.



This is a shot of my truck with the LiPos and LVC all hooked up.



A simple block drawing I made of the LVC hookup. I had to use a futaba servo extension to make it all reach.



This is a shot of my first race with the LiPo packs. My truck is the Silver/Red/Black truck with yellow wheels. I started 4th, this is was taken seconds after the horn. The truck rocketed off the line. You can see the #2 truck, also a brushless E, couldn't get up enough speed to clear the double. I'm about to soar past him. The Revo behind me isn't quick enough to launch off the jump like my E....



Just a nice picture of my FMA LiPo powered Brushless E-Maxx soaring over the triple. Thanks to ForcePhotography for the action race shots!

[MetalMan]

Another happy member to the growing Lipo family! Glad you are pleased with them!

[gixxer]

dave,
good to see that you are happy with your lipo set. now I am sure you are going to be forcing that orange truck of the Gentry's to be getting some soon. also it looks like you guys change the track since dan and I visited earlier this year.

[Serum]

nice truck too!!

[rhylsadar]

hi
nice truck!
what motor are you using? looks like a feigao L size.
and what are the actual runtimes now with 6400mAh?
bye
rhylsadar

[Dafni]

Rhyl, he said he uses 1P2S. That would be 3200mAh for a 1P Scorpion pack. (assumed he had them in series, of course)

MacII, thanks for this detailed report. I am waiting for my own Lipos at the moment. I hope I won't be dissapointed.

Thanks for sharing!

[Serum]

Hi Rhylsader!

Long time no see! How are you doing? any news about your schulze controller? I'm curious what went wrong. it can't be the combination of the controller/motor..

a 4S1P pack, and it are 3200 cells, no 6400.
Those FMA packs use Kokam 3200 20C cells.

[rhylsadar]

hi
right i read that wrong. i thought it were 2 parallel. anyway i am still interested in the runtime. i read that some drive with 3200mAh lipos much longer than with IP 3800mAh. interesting. might be due to the better performance/weight ratio.

@serum
i have sent you some pn in the indy forum. some time ago...;)

bye
rhylsadar

[Serum]

Sorry? Indy forum you say?

I didn't read any pm from you Rhyl? last post was about the preformance of the 7XL on 16 cells. We didn't communicate about the broken schulze? I asked you, but i didn't get a reply? I guess it's living a happy life, somewhere in PM land.. ;)

[crazyjr]

Thanks MacII. I've been thinking about these batteries and charger and have heard nothing but good things about them everywhere, so this might be my Lipo's of choice when i take that step

[Papa]

Rats.... I can not see the pics... what gives?:M: I have the scorpion packs on my short list. I to am interested in what kind of runtimes you have been able to get. What is the motor speedo combo? Did you use a UBEC? How did you mount the packs? Thats enough Questions for know.:p

Thanks in advance, Finally someone that has actually used the Scorpions.:D
PAPA

[Dafni]

Too bad you can't see the pics, papa. Some nice action shots.
He uses an UBEC, and the batts were held in place by some zip-ties, 3 ties on each batt.
ESC looks like a Schulze, and the motor will be a Nemesis or Wanderer (can't tell due to the RCM heatsink)

DAF

[Serum]

Yeah, it are without a doubt the BEST pictures i have ever seen.. :p :L:

[Papa]

Any clue why I do not get the Pics? :M: :C: I found the action shots on Force photography. And now in the post reply, I see a naked shot?