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Bms for Nissan Leaf batteries 8-cells Module.

Kahungo

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Jan 10, 2022
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Hi, I am looking for ideas on setting up an off grid battery bank, I have 12 modules of Nissan Leaf 8-Cells batteries and was planning to have them set on 24V as I already have a 24V outback inverter and Flexmax80 to charge the battery bank. I have been reading and looking BMS to go on this battery bank with no luck or not knowing which BMS Would work with 24V configuration of the batteries. Anyone with any idea? I would appreciate
 
When you say 24 volts do you mean four modules ( eight cells)? That would be 32 volts or more. Does your Outback inverter handle that voltage?
I have used and Overkill Solar BMS for a 12 volt system and they make a 24 volt BMS (8S) that can be adjusted for the voltage of that chemistry. If you are literally saying 24 volts or six modules then you need a 6S BMS and that is more difficult.
 
If you're talking Gen2 like this https://www.egmcartech.com/parts/Ni...-Module-Lithium-Ion-0-5-kWh_144072727672.html (also relevant if you talking Gen1)
1641871464432.png

These are lithium-ion - e.g. same voltage range as 18650 lithium-ion / 4.2v max and 3.0v typical min. Each unit is 2s. To make a 24v nominal range battery you would use 3 and 1/2 (e.g. use center tap of the 4th unit) to get 7s. 7 units can be used to make a 7s2p config.

7s / 24v ....
4.2 * 7 = 29.4v max
3.0 * 7 = 21.0v min Discharge knee is likely 3.4v-3.5v - so 3.45v * 7 = 24.1v min as a practical matter.

If you use 4 in series - that's 8s which is higher than normal 24v range equipment.
4.2 * 8 = 33.6v max - This is what @Ampster is warning about.
3.0 * 8 = 24.0v min Discharge knee is likely 3.4v-3.5v - so 3.45v * 8 = 27.6v min as a practical matter.
 
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Look at a Batrium core bms. I think they may have some special stuff for leaf batteries. (Or maybe it is now just the K9 for the cell monitor).
Probably looking at Batrium Core, Shuntmon, and leafmon or K9.

Good luck!
 
24V is the system or battery bank configuration. The batteries are 2 module packed as one module, with 8 cells total. Each module is about 16.2V. The whole battery pack is 12 pieces of double modules. Where can get Overkill BMS? If I figure out how to arrange the battery bank to 24V system then could know what Kind(in configuration) of BMS do I have to get, or get the BMS then configure the battery arrangement according to the BMS.
I have attached the photo of how the modules looks like.
 

Attachments

  • aesc-new-battery-module-specs.png
    aesc-new-battery-module-specs.png
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If you're talking Gen2 like this https://www.egmcartech.com/parts/Ni...-Module-Lithium-Ion-0-5-kWh_144072727672.html (also relevant if you talking Gen1)
View attachment 79168

These are lithium-ion - e.g. same voltage range as 18650 lithium-ion / 4.2v max and 3.0v typical min. Each unit is 2s. To make a 24v nominal range battery you would use 3 and 1/2 (e.g. use center tap of the 4th unit) to get 7s. 7 units can be used to make a 7s2p config.

7s / 24v ....
4.2 * 7 = 29.4v max
3.0 * 7 = 21.0v min Discharge knee is likely 3.4v-3.5v - so 3.45v * 7 = 24.1v min as a practical matter.

If you use 4 in series - that's 8s which is higher than normal 24v range equipment.
4.2 * 8 = 33.6v max - This is what @Ampster is warning about.
3.0 * 8 = 24.0v min Discharge knee is likely 3.4v-3.5v - so 3.45v * 8 = 27.6v min as a practical matter.
 
They looks like the attached photo
 

Attachments

  • Battery.th.png
    Battery.th.png
    345.8 KB · Views: 11
If you're talking Gen2 like this https://www.egmcartech.com/parts/Ni...-Module-Lithium-Ion-0-5-kWh_144072727672.html (also relevant if you talking Gen1)
View attachment 79168

These are lithium-ion - e.g. same voltage range as 18650 lithium-ion / 4.2v max and 3.0v typical min. Each unit is 2s. To make a 24v nominal range battery you would use 3 and 1/2 (e.g. use center tap of the 4th unit) to get 7s. 7 units can be used to make a 7s2p config.

7s / 24v ....
4.2 * 7 = 29.4v max
3.0 * 7 = 21.0v min Discharge knee is likely 3.4v-3.5v - so 3.45v * 7 = 24.1v min as a practical matter.

If you use 4 in series - that's 8s which is higher than normal 24v range equipment.
4.2 * 8 = 33.6v max - This is what @Ampster is warning about.
3.0 * 8 = 24.0v min Discharge knee is likely 3.4v-3.5v - so 3.45v * 8 = 27.6v min as a practical matter.
I have 12 Modules.
 
If you're talking Gen2 like this https://www.egmcartech.com/parts/Ni...-Module-Lithium-Ion-0-5-kWh_144072727672.html (also relevant if you talking Gen1)
View attachment 79168

These are lithium-ion - e.g. same voltage range as 18650 lithium-ion / 4.2v max and 3.0v typical min. Each unit is 2s. To make a 24v nominal range battery you would use 3 and 1/2 (e.g. use center tap of the 4th unit) to get 7s. 7 units can be used to make a 7s2p config.

7s / 24v ....
4.2 * 7 = 29.4v max
3.0 * 7 = 21.0v min Discharge knee is likely 3.4v-3.5v - so 3.45v * 7 = 24.1v min as a practical matter.

If you use 4 in series - that's 8s which is higher than normal 24v range equipment.
4.2 * 8 = 33.6v max - This is what @Ampster is warning about.
3.0 * 8 = 24.0v min Discharge knee is likely 3.4v-3.5v - so 3.45v * 8 = 27.6v min as a practical matter.
They are 8.1V
 
Look at a Batrium core bms. I think they may have some special stuff for leaf batteries. (Or maybe it is now just the K9 for the cell monitor).
Probably looking at Batrium Core, Shuntmon, and leafmon or K9.

Good luck!
Thanks. I Appreciate
 
They are 8.1V
They are actually 2 separate lithium-ion cells of 4.05v each in series in that container - the center tap let's you access each individual cell in the metal container. Each cell (individually) will have a sense lead to any BMS you choose. The Batrium system has 'bolt on' leafmons that are convenient - here's a Batrium info page w/youtube showing details

You could also do the K9 form of Batrium but you'll need to run the sense leads to each cell instead of bolting on leafmons. :)
 
Last edited:
If you're talking Gen2 like this https://www.egmcartech.com/parts/Ni...-Module-Lithium-Ion-0-5-kWh_144072727672.html (also relevant if you talking Gen1)
View attachment 79168

These are lithium-ion - e.g. same voltage range as 18650 lithium-ion / 4.2v max and 3.0v typical min. Each unit is 2s. To make a 24v nominal range battery you would use 3 and 1/2 (e.g. use center tap of the 4th unit) to get 7s. 7 units can be used to make a 7s2p config.

7s / 24v ....
4.2 * 7 = 29.4v max
3.0 * 7 = 21.0v min Discharge knee is likely 3.4v-3.5v - so 3.45v * 7 = 24.1v min as a practical matter.

If you use 4 in series - that's 8s which is higher than normal 24v range equipment.
4.2 * 8 = 33.6v max - This is what @Ampster is warning about.
3.0 * 8 = 24.0v min Discharge knee is likely 3.4v-3.5v - so 3.45v * 8 = 27.6v min as a practical matter.
 

Attachments

  • Battery.th.png
    Battery.th.png
    345.8 KB · Views: 2
They are actually 2 separate lithium-ion cells of 4.05v each in series in that container - the center tap let's you access each individual cell in the metal container. Each cell (individually) will have a sense lead to any BMS you choose. The Batrium system has 'bolt on' leafmons that are convenient - here's a Batrium info page w/youtube showing details

You could also do the K9 form of Batrium but you'll need to run the sense leads to each cell instead of bolting on leafmons. :)
Thanks. I appreciate
 

Attachments

  • Battery.th.png
    Battery.th.png
    345.8 KB · Views: 2
If you're talking Gen2 like this https://www.egmcartech.com/parts/Ni...-Module-Lithium-Ion-0-5-kWh_144072727672.html (also relevant if you talking Gen1)
View attachment 79168

These are lithium-ion - e.g. same voltage range as 18650 lithium-ion / 4.2v max and 3.0v typical min. Each unit is 2s. To make a 24v nominal range battery you would use 3 and 1/2 (e.g. use center tap of the 4th unit) to get 7s. 7 units can be used to make a 7s2p config.

7s / 24v ....
4.2 * 7 = 29.4v max
3.0 * 7 = 21.0v min Discharge knee is likely 3.4v-3.5v - so 3.45v * 7 = 24.1v min as a practical matter.

If you use 4 in series - that's 8s which is higher than normal 24v range equipment.
4.2 * 8 = 33.6v max - This is what @Ampster is warning about.
3.0 * 8 = 24.0v min Discharge knee is likely 3.4v-3.5v - so 3.45v * 8 = 27.6v min as a practical matter.
 

Attachments

  • Battery.th.png
    Battery.th.png
    345.8 KB · Views: 1
If you're talking Gen2 like this https://www.egmcartech.com/parts/Ni...-Module-Lithium-Ion-0-5-kWh_144072727672.html (also relevant if you talking Gen1)
View attachment 79168

These are lithium-ion - e.g. same voltage range as 18650 lithium-ion / 4.2v max and 3.0v typical min. Each unit is 2s. To make a 24v nominal range battery you would use 3 and 1/2 (e.g. use center tap of the 4th unit) to get 7s. 7 units can be used to make a 7s2p config.

7s / 24v ....
4.2 * 7 = 29.4v max
3.0 * 7 = 21.0v min Discharge knee is likely 3.4v-3.5v - so 3.45v * 7 = 24.1v min as a practical matter.

If you use 4 in series - that's 8s which is higher than normal 24v range equipment.
4.2 * 8 = 33.6v max - This is what @Ampster is warning about.
3.0 * 8 = 24.0v min Discharge knee is likely 3.4v-3.5v - so 3.45v * 8 = 27.6v min as a practical matter.
Any ideas on configuring this modules? I have 12 modules of this type, they're 8.1V
 

Attachments

  • Battery.th.png
    Battery.th.png
    345.8 KB · Views: 1
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