Allex
100 MW
This is LiPo thread, but ok we can do a comparison.
I agree that lipos are modular, and you can easily connect them how you like it. But you can do the same with cylindrical cells, but this will requeire some work preparing them in modules with connectors.
As for space and weight here are some calculations(please correct me if I am wrong).
If we take one of the best 18650 in terms of energi density (Sanyo GA 3,6V 3,5Ah) we get that you can fit:
GA 12.6Wh 18x650mm total: 16.54CC 0,76Wh/cm3
0,76Wh per cubic centimeter
Then we can take the new and popular Multistar High Capacity 4S 8000mAh we get that you can fit:
MS 118,4Wh 142x49x43mm total: 299.194cc 0,4Wh/cm3
0,4Wh per cubic centimeter
I had to count above several times because the figures differs by a lot! You can almost fit twise as much energy in the same space.
How about Wh/kg?
GA:
12,6Wh/45g=0,28wh/g or 280Wh/kg
Multistar Lipo:
118.4Wh/643g=0,184wh/g or 184Wh/Kg
Same thing here, you get 96Wh more or less for each kg
And its is up to you to decide weather it is worth to carry 2kg of 560Wh or 2kg of 368Wh
But lets take those popular hard case packs, they are really horrible in terms of power density and you can almost compare them to Lead acid when taking 18650 into account
http://www.hobbyking.com/hobbyking/store/__26801__Turnigy_5000mAh_4S1P_14_8v_20C_Hardcase_Pack_UK_Warehouse_.html?strSearch=turnigy%20hardcase
These babies have 0,268wh/cm3 or 140Wh/Kg
So if you want a 1000Wh battery, the question would be weather it is ok for you to carry those 7Kg of cardcases or could it maybe be better to invest in 3,6kg of 18650?
But of course, if the price your main concern, then go for lipo, or?
What about USD/Wh?
Hardcase is about 2,9Wh/USD 345Bucks for 1000Wh (you need connectors and cables to connect them)
GA is about 2,52Wh/USD 398Bucks for 1000Wh (but then you need spot welder[soldering iron works fine, my pack still works perfectly after a year] and nickel strip)
Again guys, please correct me if I am wrong here somewhere!
I agree that lipos are modular, and you can easily connect them how you like it. But you can do the same with cylindrical cells, but this will requeire some work preparing them in modules with connectors.
As for space and weight here are some calculations(please correct me if I am wrong).
If we take one of the best 18650 in terms of energi density (Sanyo GA 3,6V 3,5Ah) we get that you can fit:
GA 12.6Wh 18x650mm total: 16.54CC 0,76Wh/cm3
0,76Wh per cubic centimeter
Then we can take the new and popular Multistar High Capacity 4S 8000mAh we get that you can fit:
MS 118,4Wh 142x49x43mm total: 299.194cc 0,4Wh/cm3
0,4Wh per cubic centimeter
I had to count above several times because the figures differs by a lot! You can almost fit twise as much energy in the same space.
How about Wh/kg?
GA:
12,6Wh/45g=0,28wh/g or 280Wh/kg
Multistar Lipo:
118.4Wh/643g=0,184wh/g or 184Wh/Kg
Same thing here, you get 96Wh more or less for each kg
And its is up to you to decide weather it is worth to carry 2kg of 560Wh or 2kg of 368Wh
But lets take those popular hard case packs, they are really horrible in terms of power density and you can almost compare them to Lead acid when taking 18650 into account
http://www.hobbyking.com/hobbyking/store/__26801__Turnigy_5000mAh_4S1P_14_8v_20C_Hardcase_Pack_UK_Warehouse_.html?strSearch=turnigy%20hardcase
These babies have 0,268wh/cm3 or 140Wh/Kg
So if you want a 1000Wh battery, the question would be weather it is ok for you to carry those 7Kg of cardcases or could it maybe be better to invest in 3,6kg of 18650?
But of course, if the price your main concern, then go for lipo, or?
What about USD/Wh?
Hardcase is about 2,9Wh/USD 345Bucks for 1000Wh (you need connectors and cables to connect them)
GA is about 2,52Wh/USD 398Bucks for 1000Wh (but then you need spot welder[soldering iron works fine, my pack still works perfectly after a year] and nickel strip)
Again guys, please correct me if I am wrong here somewhere!