Building a 18650 EV Pack, 300A - Product Recommendations?

[evchris]

Building an EV battery pack from 2000+ of a leading brand of 18650 li-ion cells, available at a good rate.

So far, the plan is to use a 6S20P layout per module, with 18 modules in total = 108S20P
Nominal pack totals: 400V, 250Amax, 24kWh

For the module BMSs, 6 readings each(1 reading for each 20P).
This would require a board of 4.1Vmax 300Amax per string, or 25.2Vmax 300Amax total per board.

So, the question is
Where can you buy a 6S BMS/shuntedPCB capable of 25.2V 300A?

Thanks in advance

 

[okashira]

Interesting, what 18650's?
Seems like model S cells.
18 6s chinese mosfet BMS's sounds like a disaster.

 

[Nobuo]

This is what I found. 6S li-ion BMS are not easy to find. Are You thinking on another configurations?

3S 300A

http://aliexpress.com/item/3S-11-1V...-constant-current-300A-pulse/32292350434.html

10S 200A cont

http://aliexpress.com/item/10S-36V-...scharge-current-suitable-10S/32222383431.html

13S 200A cont

http://aliexpress.com/item/13S-48V-...-suitable-13S-lithium-battery/1894364010.html

20S 150A cont

http://aliexpress.com/item/60v-20S-...t-150a-peak-200A-Russia-free/32240942981.html

24S 200A cont

http://aliexpress.com/item/24Series...harge-current-suitable-24S-li/1896122133.html

 

[jateureka]

The BesTech D170 (40 MOS) can do 300A, according to their web site.
http://www.bestechpower.com/222v6spcmbmspcbforli-ionli-polymerbatterypack/

I have not used these myself, but there is discussion on this vendor and the BMS in this thread here http://www.endless-sphere.com/forums/viewtopic.php?f=14&t=50207

I am also looking for a high current BMS for my Leaf battery module pack that I am trying to add to my Zero. I need 14s and 220A nominal 450Ap.

 

[evchris]

Are there any BMS units capable of 300A maximum, at a decent price - not from china?

 

[Nobuo]

No matter what supplier do you choose for the BMS. 90% are made in china. I'm sure there are BMS made in USA and EU but it's hard to verify. If anyone can help I'm interested too in sources for high quality BMS

 

[pm_dawn]

Why do you want a BMS with current control.
You already have a perfectly good current controler in the motor controller/inverter.
Use that instead.
Less stuff to carry the current......
Use the throttle input or if you have some kind of BMS input, like on the Zero, I guess you could actually tap right into the inverter.
Much better solution imo.

/Per

 

[jateureka]

Are there any BMS units capable of 300A maximum, at a decent price - not from china?

Sure, depends what you call decent. Most are the 'on cell' type LVD/HVD PCB with CAN bus back to a main control PCB and the current is monitored by a hall-effect current sensor rather than a shunt resistor. I looked in to Batrium, Orion, ZEVA and CleanPower Minibms for use with my Nissan Leaf battery pack at 14s2P and prices started at about $500 AUD.

There is info on re-using the Nissan LEAF BMS so may be worth looking at also. IF you go this route then make sure you get the contactor module as it contains the current sensor. Some info here http://forums.aeva.asn.au/topic4278.html

 

[jateureka]

Looks like the Nissan Leaf BMS is only good up to 96 cells, so you'd need to use two.

 

[999zip999]

Headways No. They have a history of uneven cells and trying to weed out a cell in a big pack ? Start with a more problem free cell. Kiriako you are reading a spec. sheet. We talked about this months ago remember. How many big packs of headway cells have you build. Plus do you have an extra pair of sense wires to monitor your pack to see if in perfect balance. Remember this is bigger then a single series 12s pack running @ 30amps for a bike and hauling some extra weight.

 

[Ohbse]

Mate you are in the wrong path regarding battery cells sellection.

You better start exploring the world of 38120 Headway or larger cells.

Could not disagree more. Straight off the mark the specific energy density is 105wh/kg vs 235wh/kg, that alone is clearly a deal breaker and clearly enough to dismiss your opinion completely. Secondly the 'advantage' of larger individual cells in reducing cell count is not much of a benefit in the real world as you need an additional 18 cells to make up the pack voltage (which is probably chosen specifically to maximise power density with the available controller/motor combination). Vastly increased weight and volume, additional complexity of cell monitoring and cell reliability an order of magnitude lower than high end 18650's. Great recommendation!