Does E-revo chassis fit A123 cells?
 

Hey guys, I'm just getting my revo ready for season '09... aah yeeaa baby! ..... and I am trying to make the chassis fit either one or two 7s1p A123 packs, but I don't know if I can do it (a single 7s2p pack will fit however).

How big are the batteries compartments on the e-revo chassis? Can they fit a pack the width of a single M1 cell?

thanks

There is a picture complete with tray dimensions in a sticky in the E-Revo section of the Traxxas forums that should answer your question. But, my first instinct is to say no, it won't fit without mods.

my 2S2P's were too wide (by about 1/2" or so). But they fit length and height wise.

So in other words, it can't be done with 14 M1 cells... bummer.

Does a 4 cell stick pack of M1 cells fit? Like a double shotgun pack, two-by-two? I'm guessing 4 cells on each side like this is the max you can technically fit in it?

This would work great actually, if only a controller could handle the extra 3.3volts @ 26.4volts... has anyone experimented with the MMM on voltage capability? Because we all know the MM could do 35% more than rated! :yes:

I do need a new controller this year, what about the RX8? Can it handle 26.4volts?

The MMM is said to work on 7s a123. I haven't tried it myself though.

7S A123 = 6s Lipo in terms of fully charged voltage, which is really all that matters.

I think a double shotgun configuration would work, but you wouldn't be able to close the lid things on the battery compartments. There is probably an easy way to keep them from sliding out.

Yah, and 8s A123 is 28.8volts vs. 25.2volts for fully charged Lipo pack. I charge my A123 packs with 10amps @3.8volts to get a proper charge curve, and faster too; so that's 26.5volts momentarily... do you remember when people had issues with 6s and glitching on the Quark? Well I don't use the lipo setting on it, i use NiMH mode and I never have issues, even with 3.8volts/cell off the start...

I might just try connecting 8s up to the Quark and see what happens... :lol:

BrianG, do you remember what the voltage rating was on the Quark FET's?

Ooh ohh MetalMan remembers! 35v, same as the Mamba Max.

Did you ever add extra caps to the input of your Quark?

Which, the replacement Quark (whats his name) sold me? He already soldered two onto the input, I'm thinking of putting more if I run higher voltage... maybe 8 total? Or I might wip out the good ole' cap bank on the Quark "Monster" http://picasaweb.google.com/SethHuls...20641650999970

35v right! I forgot... well, unless the Quark has some kind of voltage shutdown from over voltage, this should work as long as I give it a good sized cap bank to reduce transients and spikes/back EMF from braking.

Ah yes, I forgot it was you who had the gargantuan cap bank! I think it should work fine LOL.

Thats the configuration my 2S2P's are in - 2x2.

Is that a brick, or stick pack?

nvm, got ya...

I finally found that Sticky you were talking about Brian... SuicideNiel did a great job on that one, thumbs up man! :rules:

According to the sticky, and if the measurements were done correctly, two M1 cells are 1mm (52mm), yes 1mm too wide for the compartment. (51mm)

Thiessen, you said 1/2 inch, I really am confused here now.... :neutral:

Then if I look at the lid, from what I can see another 8mm of headspace in itself. So, wouldn't 4s pack fit in each side? Am I making a mistake somewhere?

From what I remember the erevo compartments were not 51mm deep. A std 45mm wide pack was a decent fit, maybe 1-2mm spare. I doubt that 2 of the m1 cells side x side would fit with the door closed.

So maybe Suicideniel made the measurements INCLUDING the extra bit in the door head space.

But, just going by the normal revo chassis, and putting 2p pack on either side, the width seems right for being able to fit 2 cells in there, unless the transmission is wider than normal?

Does anyone HAVE an E-revo? If so, could get you to do a small favor and test fit 2 M1 cells side by side length wise with the truck?

Please and thank you!

I've tried running A123 cells in e-revo in all kinds of configurations. No go, unless you want to strap them in somehow without using the doors.

MMM work fine with 8S A123... look here......

http://www.rc-monster.com/forum/showthread.php?t=20899

I tried them in an E-Revo that was sitting in the hobby shop. So it likely had the foam on the inside. Remove the foam and you get to the 1mm difference. Then add on your wrapping material - likely another mm or two.

I think a pair of velcro straps in lieu of the door would work just fine - might be difficult to find a spot to attach the straps though.

Okay... so they don't fit with door, check. Velcro sounds like a not bad idea, and I'm sure if I did this I could find a way to attach the velcro to chassis.

Lucariel, that's good to hear it can handle 8s a123 pack, thanks for link... btw, your eagletree seems to be off as far as voltage reading, I see 25 volts, should be 26+volts.

Man oh man this bugs the heck out of me that Traxxas couldn't give a little extra head space for A123 packs... I wonder if A123 is ever going to come out with the prismatic (flat) cells?

BTW, Lucariel... is there a LiPo settings and a NiMH setting on the MMM? I'm assuming yes, but just making sure. Was there any issues running 8s? Glitching, stuttering?

i use 2s 2p a123 in my e-revo and the only thing i done was put some spacers between screws compartment boxes and boxes..
fit good, run great eaven being only 13.2 volts and durable and stable as a rock!!
i don´t exchange mine for lipos......

regards

was this with LIPO's or A123's?

crazyjr, if you are referring to the glitching issue, I mean 6s lipo packs with the Quark... I remember ppl having problems with it, but I think it's only when you use lipo mode on the Quark, NiMH mode is not prone to this issue.

timaneli, so you fit 2 cells wide pack in the boxes then. Well makes sense if you look at the 51mm measurement of the boxes, and 52mm of a 2 cell wide M1 pack. What kind of gap is in the bottom of the hatch/cover/door/lid (whatever you want to call it) Can it be filled in with some kind of sticky foam?

2s2p is 6.6V

He probably meant dual 2s2p, which would be 13.2v...

K well what all does a person need then to convert the normal revo 3.3 to BL e-revo? I know I need the chassis, what about the transmission (i want that), battery covers?, receiver box... does Mike carry any of this stuff?

Could I get a little shopping cart list of things I will need, just put in your two cents/knowledge....



"And anyways, you guys think you're smarter than me, and who knows, maybe you are. But what I know is when yer all grown up you gotta do illegal $#@! once in a while and have little bita fun and machurinate into a better person... and you know you're thoughts might be better than mine, but I have thoughts goin around in my head too about different thinkins and brain things you can use and doin different things... so F#$K off, and I think I know whats best for my daughter, and my thoughts and feelings of there own sometimes.... "

Ricky!

yes. i mean 13.2v at 4600mah.
is more then enough for small or regular tracks.
i run this cells with my hobbywing combo with 2350kv motor geared for 40mph.
is more then enough to smoke nitros if you know what i mean!!
i don´t think for a e-revo is needed more voltage and power then that, maybe more run time for packs!!
i run the car in this setup for 3 months with sucess without any thing break!!
the cells fit the compartments perfectly in size and is 4 cells for each pack wired in paralel and connect in series.

mah... 4s2p would be okay i guess, considering it's 2300kv motor (how big BTW?)

I have had my Revo since fall of 2007 I haven't broke anything either... except for suspension arm, my fault.

My Revo running 7s1p and 7s2p packs running 1512 Neu(1700kv) has plenty of power (~1300watts) and agility with the 1p pack... the 7s2p has noticeably more power(2500watts...theoretical) and punch but I don't like the feel of it compared to the 1p pack... too heavy and not as agile.

Well I made an 8s A123 pack and it doesn't work with the Quark... I plug it in and turn the switch, it makes an alarm beeping sound (obviously for over-voltage protection)

Well, I think I am going to get either some flightpower EON X30's, or the ThunderPower 40C packs... I am thinking more towards the TP packs however just because of the best voltage holding ability. I am sure they are both good choices.

I just need the E-revo chassis now... :yes: