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Thread: thoughs on packs

  1. #1
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    Default thoughs on packs

    Im looking for thoughts on running packs in P setup.

    Im comparing a single 4s 10,000mah pack versus two 4s 5,000 mah packs wired in parallel? What are the pluses and minuses?
    Steven Vaccaro

    Where Racing on a Budget is a Reality!

  2. #2
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    Potentially better weight distribution on a 2P setup, but depends on hull configuration.
    Better economy on a 2P setup, for those with budgets and no sponsors anyways
    faster charging on 2 separate packs

    Less resistance on the 1P configuration
    Vac-U-Tug Jr (13mph)

  3. #3
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    first the obvious...less connections with one pack compared with 2 connectors on each of the two packs with total 4 connectors. Then on esc side also a parallel connector is needed. So more moves to connect two batteries vs one and as well as charging. Then to my understanding two packs being shared is less stressful to the batteries compare to one. Also, with two packs you can play around with positioning or placement inside the boat for better balance compared to one ...this can be crucial in making the boat run more stable. Also, if size matters then obviously a single 4S 10000mah is physically larger than two 4S 5000mah. Then with two packs you have to make sure both packs are equal , meaning you can’t just slap one one brand new 4S battery and the other is a battery with many cycles. So both batteries must have equal IR( internal resistance) otherwise the weaker battery will not perform as good as the better battery and drain , heat up faster.The esc will also benefit because I believe power draw from two batteries is better than from one

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    Quote Originally Posted by Bp9145 View Post
    first the obvious...less connections with one pack compared with 2 connectors on each of the two packs with total 4 connectors. Then on esc side also a parallel connector is needed. So more moves to connect two batteries vs one and as well as charging. Then to my understanding two packs being shared is less stressful to the batteries compare to one. Also, with two packs you can play around with positioning or placement inside the boat for better balance compared to one ...this can be crucial in making the boat run more stable. Also, if size matters then obviously a single 4S 10000mah is physically larger than two 4S 5000mah. Then with two packs you have to make sure both packs are equal , meaning you can’t just slap one one brand new 4S battery and the other is a battery with many cycles. So both batteries must have equal IR( internal resistance) otherwise the weaker battery will not perform as good as the better battery and drain , heat up faster.The esc will also benefit because I believe power draw from two batteries is better than from one
    Thanks. My thought is on getting rid of all the wire and connections. Its a mono, so i can still move the battery forward and backward as needed.
    Steven Vaccaro

    Where Racing on a Budget is a Reality!

  5. #5
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    What Im finding with 10,000mah packs is the c ratings are much lower. Im wondering if they are more inline with being accurate than the 5000mah packs.
    Steven Vaccaro

    Where Racing on a Budget is a Reality!

  6. #6
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    What I’m understanding is that these bigger packs are used in drones requiring long flights for arial photography and these particular drones do not have high amp draws thus lower C ratings. With fe boats with high amp draws we can stack, parallel , series multiple smaller packs with high C ratings. Also, whether smaller or bigger boats we can play around with battery configuration where drones like to keep the weight down so they can have longer flight times

  7. #7
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    Quote Originally Posted by Bp9145 View Post
    What I’m understanding is that these bigger packs are used in drones requiring long flights for arial photography and these particular drones do not have high amp draws thus lower C ratings. With fe boats with high amp draws we can stack, parallel , series multiple smaller packs with high C ratings. Also, whether smaller or bigger boats we can play around with battery configuration where drones like to keep the weight down so they can have longer flight times
    That makes sense, thanks!
    Steven Vaccaro

    Where Racing on a Budget is a Reality!

  8. #8
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    Quote Originally Posted by Steven Vaccaro View Post
    What Im finding with 10,000mah packs is the c ratings are much lower. Im wondering if they are more inline with being accurate than the 5000mah packs.
    No it is just different tech in the cells, there is a compromise in cell design between power density and energy density. If you design for the power density you get cells like the Turnigy Panther 75C cells with a tiny IR that are hella powerfull but weigh 630g for a 4s 5000mAh pack, and if you design for the energy density you get cells like the Redzone 20C cells that have a much higher IR but weigh only 560g for a 5300mAh 6s pack.

    I mention the Redzone packs as being at the energy density end as like the panthers they are cutting edge cells, and are what we race with in Naviga if we don't run energy limiters, and our racing is 6 minutes in duration so we pull an average of 10C and a 20C marketed pack is about the least we can get away with. As Bp9145 alluded to, big multirotors are the biggest consumer of packs significantly over 5000mAh in the hobby area and they are after 20 min flights, nearly all hovering, which is only 3C, so I am not surprised you are finding that most very high capacity cells are of a lower C rate than you are used to, but I expect that you will find that their weight per capacity is lower too.

    You can turn the energy density vs power density compromise from a line into a triangle by adding cost, technology marches on and both energy density and power density have improved massively since LiPos came out, and is continuing to improve, so there are older LiPos sitting on shelves, and cells still being made on old production lines without the latest tech, which can't possibly compete with the latest cell tech in performance and has to be sold at a cheaper price to have a place in the market, as these large packs are expensive it is not uncommon to use older tech cells in them to bring the price down, so you may find big packs without particularly good energy or power densities, but with a good price per capacity.

    Pick your poison, like anything else in boating there are compromises to be made, and the best cells for me may probably won't be the best cells for you.
    Paul "tug Killer" Upton-Taylor, Cat lover.
    FastElectricBoats.co.uk

  9. #9
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    Thanks for the info. Im thinking I might be better off with paralleling packs.

  10. #10
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    Quote Originally Posted by NativePaul View Post
    No it is just different tech in the cells, there is a compromise in cell design between power density and energy density. If you design for the power density you get cells like the Turnigy Panther 75C cells with a tiny IR that are hella powerfull but weigh 630g for a 4s 5000mAh pack, and if you design for the energy density you get cells like the Redzone 20C cells that have a much higher IR but weigh only 560g for a 5300mAh 6s pack.
    Where can I find these RedZone packs?
    What other high energy density cells do you know of?

    Revo 435, 40C ,5000 Mha, 3s cells come out to 158 Wh / Kg.
    Revo 420, 40C, 3300 Mha, 6S cells come out to 146 Wh / Kg.
    Revo 420, 70C, 5000 Mha, 3s cells come out to 122 Wh / Kg.
    I did the calculation with just the stated data, not anything measured.
    Cheetah, Super Rio, (Mod) Starship (Mod and sold),

  11. #11
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    This might seem like silly reasoning but some of my cell combos multi-task. For instance, a set of cells that gets raced in P mono on Friday might do double duty in a P sport on Saturday. Not all races allow that but it's a nice option. Same thing depending on which race I'm heading to. One race might not even have P mono but does have P sport. I don't have to buy more cells. A 10,000 mah chunk isn't fitting in a hydro of any kind. A nice 4s5k single pack can work in P hydro (rigger) too with the right setup. A 10k brick?.......single application.

    All that said.......cells that multi-task don't hold up as long for obvious reasons. Especially at my house.
    Noisy person

  12. #12
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    Stop teaching Tyler to Arc weld with lipos.
    Nortavlag Bulc

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    I will tell you about the boat race packs used or seen used a lot.

    Redzones (Fullymax's retail batteries) are available on the RCFactory website but it is a PITA to navigate if you don't know Chinese, you have to purchase by email, and postage isn't cheap, so unless I want a lot I would buy from Ecomaster

    Tenshock are available from the Tenshock website, and have a number of dealers in Europe too.

    RoaringTop sell them too and advertise 230Wh/kg.

    We have added the option of electronic limiters to our rules to level the playing field, so redzone and roaringtop also sell limiter batteries that are more of a compromise between power density and energy density, so if you want very high energy density the ones marked limiter are not the ones to go for.
    Paul "tug Killer" Upton-Taylor, Cat lover.
    FastElectricBoats.co.uk

  14. #14
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    Running 2P even with identical total mah always provides more effective power.
    This has proven to be true in several different race set-ups.
    Team HRB USA / Pro Marine
    NEU Motors / Rico Racing/ Castle Creations
    2018 IMPBA FE High Points "National Champion"

  15. #15
    Noahoscar986 Guest

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    Found Dear?

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