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  1. #1
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    Mamba Monster... LiPo's and broken parts. Help.

    I drive a Slash 4x4, which I love, but my old man bought me a Brushless E-Maxx Mamba Monster for my son and myself to bash with. Ive already rebuilt the front end twice, now with RPM's... It's been quite a learning experience.

    I have 6, 2S 5000 MAH LiPo's and two 3S 4000 MAH LiPo's that I run in my Slash. I tried running two, 2S LiPo's in my son's E-Maxx and I think it killed one of them. I do have the Castle Link and I did reprogram it to tune back the punch control and set it to the correct LiPo mode... (I did whatever the program said for 2S, maybe I should've left it on "auto-LiPo"?). Maybe it was a bad battery, or maybe I didn't charge them correctly, but now I'm afraid to run them. Do I need a bigger battery for my E-Maxx? What kind of charging should I use? Always balance? I have a Venom pro charger plus, and I love it.

    Any recommendations on other commonly broke parts that I should keep around?

    OHH, I almost forgot. I know the Castle setup is NOT waterproof. That said, if I wanted to waterproof it, what could I do? And in stock trim, am I okay to drive in the snow....? I'd imagine if it's not waterproof, that would mean no snow either... Any info would be great.

    Sorry for such a long post!! I hate leaving details out, lol!

  2. #2
    RC Turnbuckle Jr. 87 GN's Avatar
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    You leave the ESC set on auto lipo..Then when you turn on the truck count the second set of tones, that is the number of cells. What is the C rating of the 5000 mAh.. The MMM needs a min of 120 amps.

    No you can not drive in snow, snow is water.. You can't get the ESC wet with out water proofing it, Youtube on how to..VOIDS warrenty..

    Edit what did you set the LVC at, should be 3.4 jmo...
    Last edited by 87 GN; 10-19-2011 at 09:47 PM.
    Would you go flip my truck back over??

  3. #3
    RC Turnbuckle Jr.
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    1) Refer to this to setup the Mamba Monster ( MMM ) esc for maximum performance:
    CASTLE LINK GUIDE

    3.4v per cell is prefered for the LVC setting, you can easily adjust the auto-lipo voltage so it wont require further tweaking once set.

    2) Yes, what is the C rating on all those lipos you were using- mah capacity on it's own means nothing really. The MMM requires atleast 120amps, you determine that by multiplying the C rating by the capacity / 1000, eg:-

    20c x 5000mah / 1000 = 100amps > not good enough

    30c x 5000mah / 1000 = 150amps > much better

    3) Always balance-charge, always store your lipos at ~3.8v per cell if you dont plan to use them for more than a few days, always charge them according to their charge rating- 1c, 2c, 5c etc ( where C equals the mah capacity / 1000 ). For a 5000mah lipo a 1c charge would be at 5amps, 4000mah = 4amps, 5200mah = 5.2amps etc etc, slower is fine, faster is only fine if they are rated for it & your charger / PSU can handle it. You almost sound like you aren't sure what settings you were using, I'd want to be certain you know what you are doing if you are feeling nervous about charging lipos- read up on them.

    4) spare driveshafts, spurs & pinions, bumpers and skids, turnbuckles maybe & rod ends- the usual kinda parts that tend to suffer from a front impact, heavy landing or cartwheel. A couple complete spare diffs wouldn't be a terrible idea either- hit up ebay.

    5) Plasti-dip & liquid latex are commonly used for waterproofing esc- the former being preferable really as it is less likely to peel off so easily. It will be a warranty void so think carefully about it- most guys dont have too much trouble with snow if it's fairly firm and they cover the chassis with a shower cap or one of the covers from ebay ( search for "E Revo Summit 1:10 protective cover" , they can make emaxx ones on request I believe ), but you don't want to be choking the esc with soft snow as it will melt down inside the casing and pose a real risk of shorting it out.

    Many guys just use a brushed system for driving in winter, you won't be able to put the power down all that well anyway with a BL system, you'll just bury the truck upto it's axles or spin out unless you have snow chains or spiked tires to get grip.

    More reading material:

    Emaxx 101:
    EMAXX FAQ

    Lipo, LVC, Brushless & Battery charger/charging guides & purchasing links:
    TUTORIALS

    Refer to this to find parts, upgrades, batts & chargers etc:
    USEFUL LINKS

    And direct from CastleCreations ( the esc manufacturers ):
    MMM FAQ

    Driver's ED Manual

    LED warning light meanings
    Last edited by ArmyofDarkness; 10-19-2011 at 11:43 PM.
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  4. #4
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    I cannot thank you guys enough, plenty of stuff to read while I'm at work today

    I run ******* 7.4v 2S 5000MAH 40c LiPo's. Couldn't beat the price, plus I enjoy wiring them up, I like to do things myself.

    If my math is correct, that should be more than okay to run in my E-Maxx...?

    In regard to the C-Link tuning, the truck was already set to auto-lipo, but when i read the description within the program it suggested I run it at 6.0 lipo mode or something, ill have to run it again to see exactly, cant remember off the top of my head. Really the only thing I changed was the punch control, just trying to make it easier for my son to drive. Maybe ill run the higher gearing... The acceleration is insane, even with the stock Nimh batteries.

    Thanks for all the help, I cannot thank you enough!

  5. #5
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    Can anyone explain what percent power increase I would get from a 5000mah 20c 3s battery vs a 5000mah 20c 2s?

  6. #6
    RC Turnbuckle Jr.
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    @Northed- ignore the default recommendations, trust your emaxx God; 3.2 - 3.4v per cell is all you need to worry about regards LVC settings- you can adjust the auto-lipo setting, or you can enter the total voltage manually ( based on voltage per cell x number of cells ). The options and exact menus you will see in the castlelink will depend on which firmware version you have loaded on the esc- v1.24 or lower, v1.25 or higher- I have 2 versions of the castlelink guide on my website to account for that, so check under the software tab in the castle link program when you next connect the esc to the pc.

    @stealth13- 50%, since 3 is 50% larger than 2- maths is fun isn't it?

    Ofcourse, that isn't so much 'power', that is just pure voltage- power is measured in Watts, and is the sum of volts x amps. However, that doesn't take into account the effect simply adding more voltage has on the setup- you get more speed, but you also get more current draw if you run the same gearing, so temps will increase and runtime may not, or atleast not as much as you might expect since there is greater current draw that drains the batteries faster, even though there is more power ( watt-hours ) in the circuit...

    You really need to take the time and study all those tutorials I keep posting, all this stuff is explained in noob-friendly language to help people make informed choices & decisions when it comes to setting up their truck and choosing batteries etc.

    I'll shoot you a PM about your lipo charging issue.
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  7. #7
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    @army, what would 40c vs 20c do then?

  8. #8
    RC Turnbuckle Jr.
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    It wont 'do' anything within the context of your original question; the C rating ( discharge rating ) is just an multiple of the mah capacity, as in how quickly the cells can be discharged before the voltage bottoms out and the cells puff up like lithium filled balloons.

    A higher C rating only means the pack will have greater punch and will be stressed less for any given load ( current draw )- it doesn't effect the total amount of 'power' the batteries have, since that is purely a sum of the capacity multiplied by the voltage, to give wattage or watt-hours.

    Knowing how much current a motor needs or wants typically is the critical thing, if the batteries cannot supply that current fast enough due to either lack of capacity or too low C rating, then the batteries will suffer and so will the esc in many cases ( the dreaded ripple-current that is caused by excessive voltage-droop ). If the capacity is large enough, and the discharge capability high enough, then the battery will be able to supply all the current the motor wants to draw and you don't have to worry about stressing out any of the components in the system. That's why a 30 or 40c 5000mah lipo is needed for a BL emaxx or erevo etc, and why a 20c will struggle, or a 30c 3000mah lipo will struggle too.
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  9. #9
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    snow-

    Shower Cap




  10. #10
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    How were your temps with that shower cap on there. Were you running 4s or 6s ?

  11. #11
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    I run both 4S & 6S

    Temps were fine, but when it's below freezing outside you can hardly feel your fingers after 1 pack.

    I like snow bashing when the snow is just right, but i like to spend the winter months building now

  12. #12
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    My 5000mah 2s are 20c. So they are having issues you think?

  13. #13
    RC Turnbuckle Jr.
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    Quote Originally Posted by stealth13 View Post
    My 5000mah 2s are 20c. So they are having issues you think?
    Have you been checking the temps on the lipos as you run them- if they run warm then yeah, they are struggling.
    As I explained above & in your other thread, your batteries are not of sufficient spec to run the MMM system; you are voiding your warranty in actual fact & if your esc were to die, castle will inform you in very stern terms that you MUST run better batteries in future or you will be liable to pay non-warranty repair/replacement fees for any other damage to the replacement esc. Not an issue if it's older than 12 months really, but castle provide more than enough info & literature to help people understand what batteries they should be running; ignore it at your peril ( ergo, read those links I keep posting, or enjoy living in ignorance.... ).
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