# BMS for Nissan Leaf cells



## sunworksco (Sep 8, 2008)

What are you installing the batteries in?


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## rockd (Mar 10, 2014)

This will be for a dump charging application - I plan to charge the batteries with something like a Manzanita PFC50 or the EMW 25kW Charger. In this type of application, I'm hearing some conflicting information:

No BMS
MiniBMS
Full blown BMS (Orion, Elithion)

I'd love to hear more opinions (even thought I'm sure the topic has been beaten to death before)


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## palmer_md (Jul 22, 2011)

rockd said:


> I'm hearing some conflicting information:
> 
> No BMS
> MiniBMS
> Full blow BMS


That sounds about right. This is pretty much the state of affairs around here, you'll get answers across the board. It's really up to your comfort level and how you plan to use it.


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## sunworksco (Sep 8, 2008)

See this EVTV video about Leaf batteries.

http://youtu.be/oZuu4YMhXI0


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## Caps18 (Jun 8, 2008)

How likely is it that these cells will drift apart from each other?

If they are balanced to start with, will you even need one as long as you don't over charge?


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## Elithion (Oct 6, 2009)

rockd said:


> Hi All,
> 
> I'm getting 20 Nissan Leaf cells delivered (total of 10kWH). What BMS would you recommend? Has anyone tried to use an Elithion or Orion with them in the past?
> 
> ...


No, not the Lithiumate Lite: it's only for prismatic cells, and your cells are pouch.
1399.03
You'd need 


The Lithiumate Pro with pouch cell boards (part number PO0000-26/3-M0000/0.5-10-000/0000-K),
Or the Orion BMS for 24 cells the Thermistor expansion module , a current sensor, 20 thermistors and a CanDapter (sorry, I don't know the part numbers).
The difference is that:


The Lithiumate is distributed (only one cable from the master to the cells, one cell board mounted on each cell measuring voltage and temperature of each cell)
The Orion is centralized (21 wires and 20 thermistors from the master to the cells)
Other than that, they are both sophisticated digital BMSs, appropriate choices for those cells, and cost about the same.


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## frodus (Apr 12, 2008)

I think if you dump charge, you're going to want to AT THE VERY LEAST monitor those cells. 25kw is a lot to dump into those cells quickly, and the cells may have more pronounced unbalance at the top and bottom.

Even if you don't believe in balancing, you can set both the Lithiumate and Orion up such that they won't ever balance, but they will warn if a cell goes high or low or overtemp.


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## nobrush (Jan 23, 2014)

frodus said:


> I think if you dump charge, you're going to want to AT THE VERY LEAST monitor those cells.
> 
> What do you mean by dump charge? I'm hoping to convert over my Geo to Leaf batteries but don't understand this term.


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## frodus (Apr 12, 2008)

Dumping a charge from one battery into another battery.


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## Roy Von Rogers (Mar 21, 2009)

I don't understand the dump charge reasons. Do you have a need for fast charge ? Otherwise just charge the vehicle with a good charger, your just converting twice.

Now if your charging the pack with solar cells I could see doing this, but to charge a pack, with a regular charger, just to dump in to another pack doesn't make sense, unless of course you need to charge your EV at shorter intervals (faster).

Whether to top or bottom balance will be your last concern, for if your doing a dc to dc charge, there are other things to consider. The dumping pack should be about 50% larger in capacity, you will also need to consider the voltage of the dumping pack, for that will determine how fast you will charge the receiving side, and since the only control will be on/off at the pack you charge, and if the amperage is considerable, there will be a limit of how much capacity you will be able to impart, for at high amps, the voltage will rise quickly, and the limiter will shut the charging process of, before pack is full.


As you can see, you will need to do some careful balancing of how big the dump pack needs to be, versus the pack that's getting charged.

Roy
Roy


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## EVfun (Mar 14, 2010)

rockd said:


> I'm hearing some conflicting information:
> 
> No BMS
> MiniBMS
> Full blown BMS (Orion, Elithion


I would like to point out Leaf batteries are NOT the LiFePO4 batteries that we have collective experience with on this list. The best way to manage Lithium Manganese cells may be different than Lithium Iron Phosphate cells.


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