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  1. #1
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    Comparing Two LiPos Need Advice

    I am getting ready to order two SPC LiPo batteries (2S) and I have it narrowed down to two choices. I need advice as to which battery would be best.

    I mainly run on the track (for fun) with the standard VXL brushless system that came with my Slash 4x4.

    Battery #1: 6000 mAh 30C

    Battery #2: 8000 mAh 20C

    I am confused because, although I want a high mAh rating, I have come to understand that a 30C at 6000 (180) would provide better performance than a 20C at 8000 (160). Would one have more punch and the other have more run time?

    Also, the 6000 mAh is a Hard Case, which I am not sure is necessary. The price is comparable. What performance characteristics will I notice and which is the better choice? Thanks.

  2. #2
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    Hard case is well worth while IMHO, I have puffed a soft case that was well wrapped up - impact damage from a jump.

    I doubt there is much real world performance difference between 160 and 180, it is only the std VXL motor.

  3. #3
    Marshal Dadx2mj's Avatar
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    I have used several of the SPC 2s 8000 mah packs and they are awesome and provide incredible run times. That being said for your application running on the track I would opt for the new 2s 6000 mah pack. The draw back to the 8000 mah is it's size and weight. The pack is pretty big and heavy and as I have learned the extra weight effects the handling of the truck. I switched back to the SPC 2s 5000 mah pack just before the new 6000 mah packs came out. I still get plenty of punch and 30+ min run times out of the 5000 mah packs. I am hearing really good reviews of the new 6000 mah hard case packs.
    BlindMan Racing
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  4. #4
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    I love hard case LiPo's. They just look more "finished" and professional. Soft packs look rigged, IMO. I have both types though, and they both work equally well, I just prefer the finished package of the hard case.

    Like dad said, I would go with the 6000mah packs as well. I would do it for the hard case and pack size. And although you probably won't notice a real world punch difference between the two, the overall higher discharge rating is better on paper.
    Turbo in the front, groceries in the back.

  5. #5
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    get the smaller 30c
    Paul
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  6. #6
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    Although not SPC batts, I have tried several 2s lipo's mostly from C***a, Comparing my 8000mah/12c/2s and a 6500/30c/2s. Performance wise they drive the same. Drag race they are the same, the 8000 does last considerably longer. If there is a fraction more punch with the 30c?? its hard to see

    Al
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  7. #7
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    Run Time Estimate

    Thanks for all the great advice guys. One more question...what kind of run time (ballpark) should I expect from the 30C 6000 packs? (35-40 mins??)

  8. #8
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    Track time will be close to an hour. I am light on the throttle and managed 1:15 runtime with one of the 6000 packs.. THIS IS NOT TYPICAL.. DO NOT EXPECT THIS... you'll be in the 50 minutes to an hour area if you are practicing... as for races.. I have a guy running one in his Jammin SCRT10 with MMP/Neu 1412 1.5D and through the 10 minute main, he was clearing the quad with no problems where as with his 5000 packs (various brands) by the end of the main its more of a triple/single than a quad...
    Slash 2wd w/ Novak
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  9. #9
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    Quote Originally Posted by rc77
    I'm confused, so he is experiencing less power on his lipo overtime? After what amount of time does his 5000 start to experience less power? Also this is consistent amongst many different brands of batteries?
    I think he was comparing the 6000mAh (right before the part of his post that you quoted) to 5000mAh .

    I have heard that with hard case LiPo's, you can't tell when they start to puff. Is this really an issue?
    ◄▲▼► SUMMIT ●○●○● 2 RUSTLER VXL's ●○●○● MERV ◄▲▼►

  10. #10
    RC Turnbuckle Jr.
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    LiPo packs show a power loss over time when used, very similar to a good quality, matched Nimh pack of similar capacity. The statement that LiPo does not lose power is just an internet myth.

  11. #11
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    Smile

    Quote Originally Posted by Jakey
    LiPo packs show a power loss over time when used, very similar to a good quality, matched Nimh pack of similar capacity. The statement that LiPo does not lose power is just an internet myth.
    +1 on this

    4.2v cells are like NiMH hot off the charger, except they stay that way for days instead of minutes. Over the rest of the discharge time you certainly lose power.

    Dropping a fresh pack in always puts a fresh smile on my face!

  12. #12
    RC Turnbuckle Jr.
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    Let me rephrase, I was not talking about packs after being stored, but as just mentioned above, fresh off the charger.

  13. #13
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    Either way, what you said is true... I meant to both agree and add on top of what you'd stated. Maybe I wasn't clear, I often have that problem.

    Regardless of the initial state of the packs (fresh or rested), as long as they are charged and at room temperature, a decent LiPo or good NiMH will lose performance over it's discharge period.

    When hot off the charger, NiMH has some "extra pep in it's step". LiPo doesn't need to be hot off the charger to have some extra pep in it's step... it just sits around at 4.2v for days or weeks, and while it doesn't take long for it to drop to 4.1/4.0v once you start discharging it, that initial bit is very peppy.

    That's all I was trying to say, sorry for any confusion!

  14. #14
    RC Turnbuckle Jr.
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    No confusion, sounds good to me.

  15. #15
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    Just did some parking lot racing, kid was running stk nimh packs and the 8000mah/12c/2s out lasted both of them and part of a 2s and finally died at 1hr,15min

    Al
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  16. #16
    Marshal ksb51rl's Avatar
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    Quote Originally Posted by SaddleSC
    I am getting ready to order two SPC LiPo batteries (2S) and I have it narrowed down to two choices. I need advice as to which battery would be best.

    I mainly run on the track (for fun) with the standard VXL brushless system that came with my Slash 4x4.

    Battery #1: 6000 mAh 30C

    Battery #2: 8000 mAh 20C

    I am confused because, although I want a high mAh rating, I have come to understand that a 30C at 6000 (180) would provide better performance than a 20C at 8000 (160). Would one have more punch and the other have more run time?

    Also, the 6000 mAh is a Hard Case, which I am not sure is necessary. The price is comparable. What performance characteristics will I notice and which is the better choice? Thanks.
    I just did a comparo (in a side-sloped large,vacant parking) of three SPC batteries in a stock 4s4. Velocities were recorded by a Garmin eTrex Vista, WAAS enabled.

    4s4 Speed Run Results

    Stock Gearing (13/54)
    8K / 12C = 29.8 mph
    8K / 20C = 31.1 mph
    6K / 30C = 31.5 mph

    Mod. Gearing (16/54)
    8K / 12C = 34.0 mph
    8K / 20C = 36.8 mph
    6K / 30C = 37.8 mph

    Notes:
    1. 8K / 12C is 22 months old & has been abused (I've learned a lot since then.)
    2. 6K / 30C was on it's first run.
    3. 8K / 20C is somewhere in between.

    I have no idea about the runtime of the 6000. I haven't had enough time to play with it. I don't even have a very accurate idea of the 8000s runtimes. I'm typically running with other people, and that means stoppages for conversations about RC and sundry other topics, trying new terrain and tricks, fixing whatever happens to break, finding parts that I or somebody needs, etc. ad nauseum. A hardcase is not a big deal to me, but I have seen a few softcase LiPos bite the dust (in E-Revos, no less) because of impacts.

    Maybe you should get both!
    Last edited by ksb51rl; 06-01-2010 at 12:24 AM.

  17. #17
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    Quote Originally Posted by rc77
    I was really only interested in this part of his comment:



    Yes, I am infering that there is a difference in power from minute 1 to minute 9... ALl of the packs my racer uses with the exception of the new 6000 go from being powerful enough to easily clear the quad at the beginning of the race to being questionable if he could clear it by race end.. so at the end, he usually ends up jumping triple, single instead of the whole quad. but with the new 6000 pack, he didnt have that "wonder if i can make it" feeling and was still jumping the complete quad at the end of the race... in other words, not enought loss of power for him to feel it...

    Im a capable driver.. I dont crash alot... but i'm not FAST.. and my friend.. he is fast.. he is one of the best locally... and placed in the top 12 or so out of 53 trucks at the last major event here which was dominated by Ryan Cavaleri won his way up from teh C main to just miss the last bump spot in the B main.. all drivers in A main were factory sponsored with one exception... one of the operators of the track here.. LOL.. SO, my friend.. he is kind of my test bench.. he's a great measuring stick for new batteries, motors, etc... hes very good, fast and consistent... so his results are easily repeated during testing.

    Hope that cleared things up for you a bit.. LOL
    Slash 2wd w/ Novak
    Rusty w/ Castle

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