Forum

Can you wire BMS in parallel for a higher discharge amp  

  RSS

EmpireofKings
(@empireofkings)
Street cred = 10 mAh
Joined:12 months  ago
Posts: 2
05/06/2018 3:28 pm  

Hello,

I have a 4s 13p 18650 battery pack. The cells are sony vtc4, and i am using the vruzend v2 kit. The pack is being built for a hexacopter we are building. According to my calculations the hexacopter will need approximately 500amps continuously at full throttle. Problem is, I only managed to find some 4s 100amp BMS. Is it possible i could wire Six of those BMS in parallel to allow a 600amp max continous discharge from the battery pack ? If not, whats the recommendation from the community ? My university professors havent been much help. So any advice will be greatly appreciated.  


ReplyQuote
Micah (Vruzend Rep)
(@admin)
Street cred = 5 Ah Admin
Joined:2 years  ago
Posts: 484
29/06/2018 8:47 pm  

Yes, that is possible. BMSs can be used in parallel, just usually not in series for higher voltages.


ReplyQuote
MattyLada
(@mattylada)
New Member
Joined:11 months  ago
Posts: 1
04/07/2018 12:16 pm  

Hi..i am a new user here.In my case, this happens because my battery pack can only deliver a continuous 30A for a 12 mile ride. I can set the max to 200A and draw up to 105A, but only for a very short trip. My battery (specifically the cell capacity) is the weak link in my system.My next battery will be a higher capacity (Ah) battery with higher capacity (e.g. 3000mA) cells, but I will still use two 36V batteries in series.


ReplyQuote
rdhoke
(@rdhoke)
New Member
Joined:10 months  ago
Posts: 1
11/07/2018 1:26 am  

18650s are not that great at High amp output in quick bursts. That is the reason that all commercial quads copters use Lithiom polymer. I know they are more expensive but you would probably be better to look into LiPoly for your quad. 


ReplyQuote
Daniel Miksa
(@danmixanet-com)
Street cred = 10 mAh
Joined:1 year  ago
Posts: 2
17/02/2019 11:14 am  

Got any videos or wiring diagrams on how to wire in parallel ?


ReplyQuote
Micah (Vruzend Rep)
(@admin)
Street cred = 5 Ah Admin
Joined:2 years  ago
Posts: 484

ReplyQuote
Daniel Miksa
(@danmixanet-com)
Street cred = 10 mAh
Joined:1 year  ago
Posts: 2
24/02/2019 8:15 pm  

Thanks.  I was actually looking for how to wire bms  in parallel.  Got and tutorials on that?  Or advice?

 

Thanks


ReplyQuote
Micah (Vruzend Rep)
(@admin)
Street cred = 5 Ah Admin
Joined:2 years  ago
Posts: 484
25/02/2019 9:18 am  

Ah sorry, I thought you meant the cells. For the BMS, you just duplicate the connections. So you install the second BMS as if the first wasn't even there.


ReplyQuote
Ebikeidiot
(@ebikeidiot)
New Member
Joined:2 months  ago
Posts: 1
05/04/2019 1:28 am  

Hello, so I'm "building" my own electric bike. Not fully just ordering parts that are already built. But my controller draws 32 amps I believe. A 48v 1500w controller. My BMS is only a 30amp BMS. What is the best option for me? Will the BMS hold up? Or if I connect another exact same battery in parallel will the BMS amperage double,so then it's a 60amp BMS? All your help would be appreciated!


ReplyQuote
Mike5hocks
(@mike5hocks)
Street cred = 10 mAh
Joined:2 months  ago
Posts: 4
26/04/2019 5:45 pm  

Would you write balance wires and charge to, or just negative bms wire and discharge wires, then wire the BMS's discharges together


ReplyQuote
Mike5hocks
(@mike5hocks)
Street cred = 10 mAh
Joined:2 months  ago
Posts: 4
26/04/2019 5:45 pm  

Would you write balance wires and charge to, or just negative bms wire and discharge wires, then wire the BMS's discharges together


ReplyQuote
Mike5hocks
(@mike5hocks)
Street cred = 10 mAh
Joined:2 months  ago
Posts: 4
26/04/2019 5:46 pm  

Cause you prob dont wanna us 2 chargers on same battery, or is that ok to


ReplyQuote
Mike5hocks
(@mike5hocks)
Street cred = 10 mAh
Joined:2 months  ago
Posts: 4
26/04/2019 8:51 pm  

I spelled funny up there, but was asking if you leave charger wires and or balance wires disconnected on 2nd BMS? Or can we charger from both bms's at same time, and charge battery twice as fast.


ReplyQuote
Micah (Vruzend Rep)
(@admin)
Street cred = 5 Ah Admin
Joined:2 years  ago
Posts: 484
04/05/2019 9:32 am  
Posted by: Ebikeidiot

Hello, so I'm "building" my own electric bike. Not fully just ordering parts that are already built. But my controller draws 32 amps I believe. A 48v 1500w controller. My BMS is only a 30amp BMS. What is the best option for me? Will the BMS hold up? Or if I connect another exact same battery in parallel will the BMS amperage double,so then it's a 60amp BMS? All your help would be appreciated!

It would not be advised to run a single 30A capable battery (BMS) with a 32A controller. You generally don't want to even get too close to the BMS limit. For example, a 20A controller would be great for a 30A BMS, so you leave some safety factor.

One solution would be to do what you suggested, use two batteries in parallel. That way together they could support 60A, but on a 32A controller they would both be providing only 16A, which is well below their 30A limit.


ReplyQuote
  
Working

Please Login or Register