LiPo for new Mamba Max Rustler?

[botmund]

I do hope I'm not asking a question asked a thousand times already. I am thinking of buying the Rustler and basically the only thing that is a big question mark is the LiPo. Been to the LHS and the dimension of the battery compartment is 137-140mm long, 42-48mm wide and 26-30mm high. The variation is because of some plastics that could be "dremeld" off/away to make the compartment bigger.

edit:
I searched the forums already for an answer...

[JeffEmbracedDC]

Well, I'm not sure about the LiPos. Personally I decded against them for right now because I'm bashing and I don't want them to freakin explode if I hit something really hard.. haha. But the rustler - good choice. Very durable from what I have seen. A friend of mine picked one up about a week ago and we have been running it about 3 times a day since. We replaced the motor with a P2K and it keeps up pretty well with my FT B3/P2K. Also, good choice of ESC. I have been highly considering getting one of these over the past few weeks and just today decided against it. Unfortunately the area I have to drivs is just too small for a brushless system. I wouldn't even use it to half of its potential unfortunately. Once I get a better place to drive it I will very likely be picking a mamba max/5700 setup for my B3. Sorry, I don't know about the LiPos, but good luck.

-J

[trxcrazy345]

rustlers are a very good chose i don't know about lipo or brushless mines stock (not for long hehe)

[pjerry]

dude any 2cell maxamps pack will fit in the same space as a stick pack, plus they are only like $10 above high end ni-mhs. i use the 6000mah in my xxx-t mf2 4.5r brushless and i get around 15-20mins. of 50mph runtime

[pjerry]

as long as you watch your temps, and balance when you charge, lipo is actually safer and harder to make explode....the explosion is just much bigger :D

[botmund]

Just for the record, LiPos are safe when you handle them as supposed to.
:)

Thanks pjerry for your info, I have a MM 5700 and a 2S would make it kinda lame would it not? I think MaxAmps only have 2S for the Rustler.

I have two PolyRC 3700mAh 3S1P. Would it make the car to unstable to stick one of these down the hatch and have the other end sticking up?

[pjerry]

well maxamps makes tons of different lipos, 2cell all the way to 5/6cell, and no your car wouldnt be lame with only 2cells, it just wont be a blazing 45mph race truck, but you cant use lipos in roar rules if your racing against ni-mhs, which is fair, but everyone is afraid of lipos for some reason...... :confused:

[JeffEmbracedDC]

well maxamps makes tons of different lipos, 2cell all the way to 5/6cell, and no your car wouldnt be lame with only 2cells, it just wont be a blazing 45mph race truck, but you cant use lipos in roar rules if your racing against ni-mhs, which is fair, but everyone is afraid of lipos for some reason...... :confused:


I'm afraid of them.... just because everyone says that they're not very stable. I'd like to know if this is true o not. I mean, people usually charge them in a fiber explosion proof bag thing, right? like a lipo sock or something? I don't know. I know that with my nimh batteries I feel confident plugging my batteries in, walking away, and coming back 20 minutes later to check on them. From what I have read you'd need temp gauges, then some kind of failsafe electrcal cutoff, I don't know.. "If you drain them too far they'll puff up!" or "if you overcharge them they'll explode!" How much do you have to overcharge them? like do you have to overcharge them for like 3 too many hours at 6 amps? I mean obviously no one is stupid enough to charge a battery at 6 amps for like 5 hours.. I'm interested in them, but from what I have read they seem pretty volitile. Some people say if you crash too hard they'll like puff up and maybe explode. Well, I f that happened in my B3 or anything it would snap the battery brace and then the chassis from expanding. And then if it could explode I'd probably have some really screwed electronics, not to mention the car. Broken chassis, melted electronics, an probably other melted parts. These are all things I've read - obviously I have no idea how true this stuff is or how much of a problem it is. I'd really like to be set straight on these lipo things. I'd really like to get in to them when I get a brushless system as long as they're safe and stable and don't requie me to constantly keep them in bags with temp gauges and volt meters and whatever else hooked up to them. Anyway, thanks :)

-J

[tcolesen]

I'm afraid of them.... just because everyone says that they're not very stable. I'd like to know if this is true o not. I mean, people usually charge them in a fiber explosion proof bag thing, right? like a lipo sock or something? I don't know. I know that with my nimh batteries I feel confident plugging my batteries in, walking away, and coming back 20 minutes later to check on them. From what I have read you'd need temp gauges, then some kind of failsafe electrcal cutoff, I don't know.. "If you drain them too far they'll puff up!" or "if you overcharge them they'll explode!" How much do you have to overcharge them? like do you have to overcharge them for like 3 too many hours at 6 amps? I mean obviously no one is stupid enough to charge a battery at 6 amps for like 5 hours.. I'm interested in them, but from what I have read they seem pretty volitile. Some people say if you crash too hard they'll like puff up and maybe explode. Well, I f that happened in my B3 or anything it would snap the battery brace and then the chassis from expanding. And then if it could explode I'd probably have some really screwed electronics, not to mention the car. Broken chassis, melted electronics, an probably other melted parts. These are all things I've read - obviously I have no idea how true this stuff is or how much of a problem it is. I'd really like to be set straight on these lipo things. I'd really like to get in to them when I get a brushless system as long as they're safe and stable and don't requie me to constantly keep them in bags with temp gauges and volt meters and whatever else hooked up to them. Anyway, thanks :)

-J

LiPos are somewhat unstable, but their stability also depends a lot on how you treat them. Discharging them too far can easily cause them to puff up, and when they puff up, they are unstable (gases are released causing the cell to puff up). Overcharge can cause such damage that the cells will erupt in flames (I don't use the work "explode," from my experience it's more of an erruption). For example, I took an old Maxamps 2250mah cell that was long gone and hooked it up directly to my 12v 30amp power supply. It puffed almost instantly, and then "erupted" in flames. Let me know if you would like the link to this vid (PM me).
As far as what will cause the cells to burst into flames, I don't know that there's any real data on that. Keep in mind that there are many different brands of cells, and while the cells may be chemically similar, subtle differences in their makeup cause some to be less prone to catching fire than others.
The key to making sure that you don't have any problems is to make sure you're around when charging the packs, and if you see anything wrong with them, isolate them and keep tabs on what's happening. For example, if you see a pack that has puffed up, don't charge/discharge it, set it to the side and make sure it doesn't get any larger. Usually when these packs puff up once they are done for, but this can usually be prevented by using a proper LVC.

I've had several of my LiPo packs ejected from my cars, usually from the velcro battery strap ripping. No problems have resulted directly from these incidents, including no puffing. Even if they did puff up, I have confidence that they would not burst into flames.

The LiPo Sack is probably the fiber bag that you are talking about. I've seen them, but have no reason to use one. I make sure that my batteries aren't damaged (puffed/dented/crushed) before using them, since using them in a physically damaged state is just asking for trouble. All of my LiPo packs are sitting on my wood workbench right now, and I'm not charging them because I'm not there to monitor the charging process.

If you find that a Lipo pack is getting hot in a certain application, then it is being worked too hard, indicating that you need a pack that can handle more current. Generally the cells should be kept below 140 deg. F, but like I said, they shouldn't be getting that hot if they are the right cells for that application.

[botmund]

I have flown my airplane straight down in the ground smashing it to pieces twice, besides that crashes which destroyed part of the plane. It is a GWS SlowStick and the Tanic LiPo is sitting unprotected on the upper side of the stick. The same Tanic's has been in my Thunder Tiger 1/18th Stadium truck and that little car has had so many bad crashes and flips that I couldn't even count them. I am still flying/driving with the same LiPo's and have had no problems at all with them.


I crashed my HPI Sprint 2 that has a top speed of about 140km/h. One of my PolyRC packs got loose, that is the different cells moves a bit inside the shrink-wrap but again no problems. I've used that pack several times and will keep using it.

I shorted one pack and it had a burnt smell to it so I got rid of it.

Those I've spoken to myself that have experience of puffed up LiPos or getting a LiPo to burn have either charged an already puffed up pack just to save money or have drawn way too much amps from a pack thus causing it to puff.

My recommendation is to try LiPos. They are not dangerous of treated correctly.
I always keep them in a ceramic pot with sand underneath and I never charge them outside this ceramic pot.

Now, so not to hijack this thread. Any more info on a 3S LiPo for the Rustler?

:)

[botmund]

Bought the Rustler and used my PolyRC 3700mAh 3S1P LiPos. They fit perfectly into the Rustler after cutting away the aft wall (under the original ESC) in the battery compartment making the compartment longer.

I've had a few goes with the MM 5700 and it is a lot of fun for sure.

:D

[littlej72]

what is a safe capacity (spec) pack to use with a stock xl5 rustler, Im just looking for longer run times, I have 8.4v packs 4500mah I use in it now, great power run times are ok, What would be useable?

[tcolesen]

My recommendation would be anything that is rated to handle 80+amps continuously.

[littlej72]

I like the max amps packs, which would be good for a stock xl5 rustler? I may go mamba, but not yet. I see all this 2s1p etc, I guess its series paralel, etc. but what is useable?

[tcolesen]

You could use a Maxamps 2s1p 5000mah pack. On this page:
http://maxamps.com/products.php?cat=59

[guver]

That's the best lipo in my opinion as far as size goes. It will replace a subC and is a 1P

Knock the rating in half though.