Battery setup lipo or others


#1

Hey guys what batteries are you guys running and what do you think is best. I was going to run 2 8s 10000mha lipos but is that the best or is there a better solution than running those lipos. Thanks in advance.


#2

Hey Dan! Lipos are a good option but not the best in my opinion. Your pack will only have 10,000mah of capacity assuming you use them in series so that will only give you 5-15min of ride time which is not a lot. I’m personally building a battery pack from 18650 lithium ion cells. Using these cells, you can customize the capacity and voltage of your pack to your needs. Building a high capacity pack 12s 40,000mah will cost only slightly more than cheap lipos (hobbyking) while being much safer and more durable. I hesitated a long time between lipo and li-ion and I finally went with li-ion even though I’m budget conscious haha! I got my cells from jehugroupbuy.com which offers a great deal on Sony VTC6 cells right now especially if you are in the US. Hope this helps!!


#3

Should you be able to post a photo of you setup because I can’t find anywhere how to build a back that is specific to our needs because I’ve been wanting to do a 18650 pack but just don’t know how to calculate all that and ya I’m in Colorado so I might just buy from that site


#4

Should you be able to post a photo of you setup because I can’t find anywhere how to build a back that is specific to our needs because I’ve been wanting to do a 18650 pack but just don’t know how to calculate all that and ya I’m in Colorado so I might just buy from that site


#5

Well, at first design your setup, look for a matching ESC + Motor (+gearbox) combo with right KV at the propeller.
Then you know at which voltage you want to run your system. Most people here use 12S since it will get really fast much more dangerous running higher voltages. But you can also use any other series combination… @Alexandre uses 8S, some other 13 or 14S.
If you know the voltage you got the series count of your battery pack. Make sure your ESC is able to work with that.
Then I would do some rough calculations about the runtime. E.g. if you plan on foiling with ~1,5kW and 1h run time, then you need a ~30Ah @12S pack, @8S it would be ~50Ah.

And then you can have a look on packs available and if you cant find any you have to consider either make one by your own or buy a custom one or just connect some smaller ones till they fit your expectations.

If you consider packs available I would have a look into E-scooter battery packs, they got around 50V-60V and 20-60Ah. Cost >500€ and have a decent BMS + charger. So you dont touch the batteries, just connect them and they work (Apple Solution, easy but somewhat pricey).

Second. you build I by yourself: really dangerous if you dont know what you do. I would not recommend building a battery by yourself if you dont have any experience. Also a >1kWh pack would be a really expensive lesson if you do any mistake (alone the bare cells will be >300€). Also you will need a fitting BMS and charger, otherwise it is quite hard to not damage the cells during high amp discharge. (maybe cheapest solution, but only if you know exactly what you do and you only order the right parts, any mistake at a big battery pack will easily result in fire and damage of many 100€)

Last solution, adding up small batteries till they fit. Usually using Lipo packs of 3S, 4S or 6S. Well, you can do that, but I would still recommend a BMS (at least for charging) and you will have similar problems as with the self build pack, only in other dimensions (you dont have to take care of every single cell, but of the whole 3S,4S or 6S pack with connections, attachment and stuff). For testing this might be the best solution since it is the easiest one and you can first try a cheap 10Ah battery and later buy more packs to have a 30Ah battery. Still you can make many expensive mistakes.

Last but not least, cylindrical cells (like 18650) are told to be “safer” than lipos. But this only applies if you use them right. Any unprotected 18650 (we only use unprotected cells since protected ones are limited at output power and much much more expensive) can be the same fire starter like a lipo pack. Also what is somehow more important, 18650 have much more voltage sag than lipos (at same capacity).

So tl,dr:
Make sure what voltage you need 2x 8S = 16S which is way higher than usual on this forum. Then what capacity you want to have.
Consider getting a expensive but fitting ready made pack the first time, than making some expensive mistakes and buying a expensive ready made pack afterwards.


#6

Unfortunately, my battery pack isn’t completed yet; the cells are still in the mail. However, if you have any basic questions I might be able to help as I am still learning about how to build these packs.


#7

What do you think about this pack


#8

well, since it is a E-Bike pack, it only has a BMS good up to 30-50A continuous. If you have a super optimized board+foil+propulsion this might work. More likely you will need up to 80A to get up foiling, and then still you might need 50A cont.
So it could work, but why not look for scooter batteries? They are more like 2-4kW output power. So you wont run them at maximum rating all the time…


#9

Can anyone point me in the right direction to build my own pack as to like planning and arranging the batteries and how to achieve 48v with how to calculate ah and how to properly connect everything so it doesn’t go BOOM. thanks in advance.


#10

to get 48v using 18650 you need 13s , 4.2v /cell will go down to 3.7-3.6v during application
try to discharge 5A /cell so 10P for a 50A application, when using 0.15mm nikel strip if using on spot welder (best)
for runing time a 3A capacity cell will not give you 3A when discharged at 2C, probably more like 2A (depending of quality) if you don’t go below 3.3v, so match the number of cells to get 20min or 40 min of riding
at the end you need bush bar (copper,) to wire the batterie cables

look at endless forum battery build to get some idea