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  1. #1
    RC Competitor
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    Batteries in parallel then in series to esc

    Anyone tried this?
    Lets just say 4x 3s 5000mah 50c gens ace batteries. Wire two batteries in parallel on each side of the boat. Then run them to the esc which is wired for series from the factory. This would give you 6s 10,000mah 50C with 500amp max discharge current. Would this work or is that overkill?

    Kinda new. Would like pros and cons. Asking because these gens ace batteries are pretty cheap and ive always had good success with them.

    And whats the difference if i did that with 4x 2s 5000mah 50c batteries. Would this way give me any faster speeds then just 2x 2s 5000mah 50c in series?

    Keep reading post that the battery doesnt push power to the esc, but the esc draws power from the battery as needed. If this is the case why did my feilun ft011 (stock battery 4s 2200mah 30c) act real funny with a 4s 50c battery and when i went back to stock battery or (sometimes used) 3s 3700mah 30c the boat acted fine?
    Last edited by BburlTM41; 05-01-2017 at 10:11 PM.

  2. #2
    RC Turnbuckle Jr.
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    You will experience slightly more power as the batteries will hold better voltage under load.

    Let's say you draw 100amps. With one pair of packs, your voltage may be 4.0v/cell under that load. With both packs, as the amp draw is split, it may hold 4.1v/cell, so you'll get more voltage which means more wattage with means more power.

    However, this will very likely be offset by the added weight which will add more drag as the boat will sit lower in the water.

    The added weight will make the boat more stable though (assuming it doesn't overload it).

    Lastly is heat. You have to make sure your system can handle it. Assume with a normal battery, the system heated from room temp to 110* in 10 minutes. You run it for double, what does it heat to now? 130? 140? What's acceptable to you? According to spec? I used to have a setup in a E-Revo that would run for 40 minutes at race pace on a race track. Yes. 40 minutes! The system never got above 110*F.

    Small disclaimer - I don't own a M41 (yet - considering one) but all this is general electric RC principle.
    BP stands for Brushless Powered - LMT1940/7 CF G2R

  3. #3
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    Thanks for the response. Tried searching this on google and couldnt really find what i was looking for. Debating to do this setup, maybe not with 5000mah batteries, maybe something less, or wire the esc for parallel and get 2x 6s batts that are 8000mah. Just 2x 3s 5000mah in series just doesnt seem like a lot of run time to me.

    Maybe its best to just get more pairs of batts and once one set is done, let the boat chill inbetween runs because you brought up a good point about temperature, didnt think about that. My esc and motor stay real cool from being water cooled but the batts just sit there and with a closed canapoy theres no air flow so the batts just kinda sit in there and bake. But with 2x 3s 5kmah batts at the end of the run the batts feel cool for the most part, they might get slightly warm so my idea may work at 10kmah

  4. #4
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    Would the amp output of 500 from the batteries be too much?. How does that work. I hear the esc takes power from the battery as needed. But also hear the battery pushes its full power to the esc. Which is true?

  5. #5
    RC Turnbuckle Jr.
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    It's not about pulling or pushing. It's about balance.

    When you apply throttle, the batteries flow electrons to the motor through the ESC to the motor. Partial throttle basically has shorter periods of connection. Full throttle connects as much as possible (the ESC has to switch phases as your motor rotates).

    A battery that doesn't have enough power will drop in voltage trying to supply the current it needs to balance the system. As the voltage drops the differential becomes less and less current is required to bring the system to balance. So eventually it levels out. A weak battery will result in less power because the effective voltage will drop which hurts the wattage.

    A good battery doesn't have the issue and can supply all the current needed while maintaining voltage. Similarly, having two batteries in parallel doubles the effective current capability of the batteries.

    Basically, your batteries can never be too good. But, even if you have a super capable ESC, if you over gear your vehicle (prop too big/aggressive for boats), you'll always be able to melt your motor no matter how good your ESC or batteries are.
    BP stands for Brushless Powered - LMT1940/7 CF G2R

  6. #6
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    Thanks for clearing that up.

  7. #7
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    Be sure If you're getting a battery it should be 30c rating or higher, Boat draws more power than RC Cars which will end up frying your batteries, boats are more on load with the propellers directly to the water so the amp. Load is different, That's why everytime you do a lipo with just 25c or lower the battery will puff because of the insufficient load that could give.
    Sharing is the best thing to do on EARTH legally.

  8. #8
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    I feel like my boat is faster with traxxas 25c over my gens ace 50c. Any idea why that is tho? I dont own traxxas batteries, i used a friends once

  9. #9
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    you cannot say that you feel it, put a gps in the boat then you will know the exact speed between them. Maybe your other batteries need more discharging.
    Sharing is the best thing to do on EARTH legally.

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