Hey Guys, So I’m new to E Boards and have lately been using lipos on my board, but wanted a longer range and more reliable battery, so I’ve decided to make a lithium ion battery pack for my board and am planning on using the Panasonic NCR18650PF cells. My configuration will be 6s6p with a total of 36 cells and about a 390Wh rating. These cells are rated at 2900 mAh and 10A discharge rate. Here is the spec sheet. The cheapest place I can find them is from battery bro for a quote of 3.27 per cells for 50 cells, but with a 95$ shipping fee!!!
Cool! But I have one question for you… Do you know how much I can draw from my batteries? They are cell 18650. 12s4p. Max. discharge current: 20A Nominal capacity: 3000 mAh Nominal voltage: 3.6 V
So to find out how much ampere I can draw? Is the formel like this: Max amp * Parallell 20 * 4 = 80 Amp So my max is 80 Amp?
Yes, for battery packs it would be (Max amperage per cell) x (number of cells in parallel)= max amperage you can draw For these cells that are rated at 10A each, a 12s4p pack would be able to deliver 43.2v(3.6 x 12)nominal at 40Amps(10 x 4 cells in parallel). That’s should be plenty for most setups.
If you have batteries that are rated at 20A and are using 12s4p then you are correct that you could draw 80A
Thank you! I thought so
With the cell batteries you buy from there. Do you need to do capacity testing? Because that would be a pain in the ass to do… With 48 batteries Im gonna have in my board.
If they’re from a reliable source like battery bro you shouldn’t have to test them, just check all thier voltages and make sure they’re the same. @Sander
Cool! Hope so Im gonna order the LG one because it was one of the best new cells of 2015 and has the most capacity amps(3000mah, 20A). But they cost USD $4.38 per cell. So for 50 it is $219. And I have a trouble of finding trust worthy BMS sites. So if you could provide me with one that would be good
Remember that with 80A and about 50v that’s about 4000w of power that you most likely will never use (unless you’re building a 4wd going up a super steep hill). If it were me I would go with the cheaper cell like the one in this group buy that can deliver less current but still has a high capacity.
I have a limited place inside the board. And if I wanted to get the max distance and max speed I would need to have 12s. 12s is greater power and greater distance then 8s.
The board looks like this inside:
Its 8 batteries on the long side. 6 on the short side.
And just to point it out the motors are 2250 Watt Each.
Damnn thats a nice looking baord I agree with you about the 12s, im just saying you would be just fine using less expensive cells thats max current was 10A. It would still be the same configuration, 12s4p, and 95% of the capacity(515Wh which should get you over 25 miles and by that time your legs have already fallen off ) but it would be about $100 cheaper for the cells if you bought it from this group buy. Also remember that you motor will most likely never draw 2200 Watts. I have a 2200 watt rated motor and at peak power I draw 1200 Watts, cruising about 250-500.
where did you get that board ?
Haha, no I havent got it yet. I have 3d designed it in Fusion 360. I and my father are gonna make a foam cut of it. And then make a mold of it. Then make it into carbon fiber by laying layers. I can provide you with some schematic I made:
It will be 3cm thick board that goes 50km/h and goes >50km distance
I agree with what you say . But the specs of the Carvon 2.5V Hub Motor has recommended battery of 10s to 12s. And the wiring in the board will be easier with 12s because then I can wire all the batteries together then having a few extra batteries in 10s. And I saw a man on a youtube video testing out the amps of the motor of the carvon. It took like 10-25 amps straight and up a hill. And that was one motor… So it would have drawn around >50 amps. And I always likes to be on the safe side But I consider going down to cheaper batteries. But I have a budget, and with those batteries it wouldn’t matter if I had the expensive ones ;). And thanks about the comment of the board .
I wasn’t saying go down to 10s, 12s is great, and if that’s best for you, stick with it! I just thought using the cheaper batteries (with the same setup 12s4p) you could save around $100 and get the same performance. And remember with a single motor going up a hill it has to do all the work, so with two they would each be doing half and I bet you would never be pulling more than 40 amps. Also to be safe if you’re using a vesc you can limit the current draw in the programming. I completely understand if you wanna stay on the safe side with the higher amp draw batteries, but if you change your mind and wanna get the Panasonic ones, let me know and we could get them for pretty cheap
Also don’t forget wherever you’re getting your batteries from, they’re gonna charge shipping and its normally pretty expensive(from battery bro for 50 cells its $93)
I honestly want the panasonics. Because its cheaper. And I get more and in the VESC settings you can limit the amp draw from the batteries so that will not exactly be a problem So How much does it cost for the panasonics for 100 and 200 quanity?
but one problem it has 100mah less… So the distance will be a little differenet. Calculation with 3000mah cells: 3000 * 4 = 12Ah 12s * 3.7v * 12ah = 53,28km
Calculation with 2900mah cells: 2900 *4 = 11.6Ah 12s * 3.7v * 11.6ah = 51.5km
So it will be 1.78km difference
for 100 its $3.10 per cell with $132 of shipping and 3% credit card fee so $455.26, and for 200 its $2.95 per cell and $173 of shipping and 3% credit card fee so $785.89. How many cells would you want?
You’re correct about the distance difference but honestly for me after a 10km ride my legs are sore. I can’t imagine what a 50km ride would do Thus I don’t think 2 km will make too much of a difference\ for you because it would be physically very difficult to go on a 50km ride.