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)

Pictures...
 

http://www.visionarycomputer.net/rc/size.jpg

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

http://www.visionarycomputer.net/rc/charge.jpg

A photo of the chargers and packs.

http://www.visionarycomputer.net/rc/maxx.jpg

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

http://www.visionarycomputer.net/rc/lvc.jpg

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

http://www.visionarycomputer.net/rc/quick.jpg

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....

http://www.visionarycomputer.net/rc/air.jpg

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

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

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.

nice truck too!!

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

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!

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.

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

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.. ;)

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

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

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

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

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?

I have got no idea Papa.. Are you using IE or another type of browser? perhaps a webaccelerator or anything like that..

IE, with XP, not sure what accelerator is? DSL connection. HAte that:mad:

Very strange.. I'm not able to upload them at this moment..

But they sure are BEAUTIFUL! :p no, it are pics of the nude car and some flying by pics..

Mike G has only one "main" win over me this year. He has been the underdog all season but he has been coming on strong at the end. I think he wants his revenge from the points series. We both will be going to the Barn this weekend to duke it out.

XRC has had 4 layout chages this year. The current layout is super fast with a real large double and a super large triple...it's a fun end of season layout, not too technical...lots of WOT.

The motor is a Feigao 10L. Run time, well, these are 3200's and I've not pushed them. So long as they can run 5 mins +30 seconds at top speed, I'm happy.

Speedo is a Schulze 18.97KWF, Motor is a 10L, yes, I use a UBEC, when you see the pix, you can see the mounting but in short, three ZIP ties.

I'm not sure why you can't see the pix, I'm hosting them on my site...if you want to go to the directory itself visit:

http://www.visionarycomputer.net/rc/

Thanks for the answers it sounds nice. I take it you make 5 minutes no problem. At our track I will have to do 10 minute mains with the Nitro Monsters, I am thinking I am gonna need the 2s2p scorpions @6400Mah.

AH HA... I went to your site directory, thanks. Nice shots, two chargers, interesting what power supply is that? :D

Thanks. Two chargers b/c I want to be able to recharge between rounds. It worked great this past Sunday. I have a CE 23 Amp Power Supply. I think it was about $140...got it at XRC.

And on the 10 mins...yeah, the 6400's should give you that and then some. I've not tried them myself, maybe soon.

Hey Papa. I have IE and XP and i have no problems with the pictures

Serum. If by upload, you mean put on your computer, i have no problems there either

MacII. Nice action pics of a very nice truck

Yeah, i ment uploading them to my webspace.. Only problems i have got is with photobucket.. (sometimes)

I dunno what the deal is. Maybe my security settings are too high? Seems like there have been a few threads where the pics have been missing. No red x's, just not there.

Sorry for the hijack. My issue with the Scorpions is having to save my pennies. Spendy but worth it I am sure.

try rightclick the pics and use the 'show picture' option..

perhaps that makes a difference.. it's more of a multimedia setting than a security setting if you ask me.

I don't have a pic to click on. right click in the thread does not give "show picture" option?

I'm running ta pair of Scorpion 6400s in my TXT-1 and getting 25-30 minutes with bashing and top speed runing.I've got a 10L/9918 combo an Emaxx tranny locked in second gear.You should have no problem outlasting the nitro crowd.

Cool, good loooooong run times. I have a lehner 1940/6 w/9918, Gmaxx single speed, strobe slipper,and UE VBS. I am psyched to finally run this thing.:cool: Just a few more pennies and I'll be ordering them up.

I have a pair of the 6400 mah scorpions myself, but haven't gotten the chance to test them on the track lately due to the weather. i plan on racing this weekend with MacII, though, so it should be a good time. I will probably use a 1930/8 motor with the 4s Lipo packs(1940/7 maybe, depending on if I can get the gearing where I need it).

http://www2.towerhobbies.com/cgi-bin...?&I=LXKLK8&P=7

Thats the one aye? whats with all the plugs? do you just use the deans plug and leave the rest?

for the price of two of those you could get 5 pairs of 7 cell ib3800's, and 5 pairs of ib3800's would last longer than those packs, but for racing they would be good cause they have long run times so you wouldnt need to pit in. but i'll just stick with normal batteries, i only bash.

The Deans lead is your power plug, that goes into your speedo. The White plug which kind of looks like a Tamiya Plug (but is not) is used only for charging, you plug it into the charger. The two radio plugs go between the speedo and reciever for a sinlge battey setup or see my diagram (2nd post of this thread) for a dual battery setup.

that is an error on the towers site, they are no 60A, but 120A continiously...

crap.. 14.8X120=a rough 1800 watts.. that should do the truck Mike..

So do you think the performance of these packs will be up to par?

No doubt.

Rule no1 with BL the maxx power the motor can deliver is the power that the batteries can deliver minus the losses..

a normal 18 pack (good cells) are able to pop out 1800 watts as well, though the 18cell packs weight more... and it seems that lipoly's are the best when it comes to HUGE current peaks..

Thanks for the info MacII,

I've been waiting to get Kokam Lipo's for a looooong time...

I've been keeping an eye on FMA's site for prices on the skyvolt packs. I went there yesterday and saw that they have dropped thier prices around 15-20% on most of thier new stuff like the skyvolts and scorpians etc.

So, I went a little crazy and spent $500 on a 6s charger, 5s skyvolt pack, both the charge protection and discharge protection modules, the DPM Led/speaker and the charger extension. Now I remember I needed to get the Impads for my pack and a power supply...

The reason I didn't get the scorpians is that they only come in 1p2s packs. I did not want to settle for sets of 2s so I went with the skyvolts. The cells are the same so they should perform just as well.

I will have to start another thread when I have data on my setup and performance.

Due to the lower internal resistance of the Lipo packs, they should get better runtimes then a comparable mah nimh pack.

I run against the nitro's as well and have to last through a 12-15 min A main. My GP3300's could easily last through a 15 minute main so I'm certain the Kokams can handle it.

Thanks again for the info.

Please do start a new thread about your experiences too. I think my favorite part of this hobby is the sharing we all do. What works, what doesn't how we can make our race days (and bash days too) just a little more fun and rewarding. Keep fighting the good fight against the Nitro trucks.