Nissan Leaf (gen 1) voltage range.

SolarDavid

New Member
C6F40023-000D-4481-AB98-DBA08BD76EEA.jpegHi Everyone.
I’m new-ish to solar power and new to this forum.

With help from a few friends, I have set up my home with solar power, powered with Nissan Leaf(Gen 1) batteries.
Was hoping you can share some ideas on the best range of voltage to keep my batteries in, to extend their life-time/cycling capacity.

I have set up my charge controllers to charge the modules up to 8v max, and shut at 7.5v.
Does that sound like a good range?

(I have set up my batteries in packs of 8 modules, 64v total/pack). My goal is to extend the life time of the batteries for as long as I can.

Should I go alter the range of charging to the battery’s?

Thanks
Dave
 

ereams65

Solar Addict
If this is the completed install, can we safely assume you're not using a BMS? If that's the case, to be both the safest for your home, and to answer your OP question, a BMS is recommended.
 

OffGridInTheCity

Solar Addict
Hi Everyone.
I’m new-ish to solar power and new to this forum.

With help from a few friends, I have set up my home with solar power, powered with Nissan Leaf(Gen 1) batteries.
Was hoping you can share some ideas on the best range of voltage to keep my batteries in, to extend their life-time/cycling capacity.
These are lithium-ion technology arranged in 2s1p per metal container - e.g. 2 lithium-ion cells in series. Each lithium-ion cell will have a standard 18650 / lithium-ion voltage range of 3.0v -> 4.2v. Typically, 3.5v-3.6v is the discharge curve knee - so that's the practical cut-off voltage as there's no power/benefit in discharging down to 3.4v or 3.3v kind of thing.

Read this Battery University page - https://batteryuniversity.com/article/bu-808-how-to-prolong-lithium-based-batteries - for insight into long life vs voltage ranges. Here's the chart (near the bottom of the page) that I built my system toward - I'm shooting for the 75-25% SoC line.
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I have set up my charge controllers to charge the modules up to 8v max, and shut at 7.5v.
Does that sound like a good range?
These have 2s1p lithium-ion cells. So 8v / 2 = 4.0v/cell. This is great for long life. Shut-off at 7.5v / 2 = 3.75v/cell. Typically the discharge curve knee is more at 3.6v or 3.55v - so you could go a little lower but its not wrong.

(I have set up my batteries in packs of 8 modules, 64v total/pack). My goal is to extend the life time of the batteries for as long as I can.
If you do 7 modules you'll have a 14s ltihium-ion battery - which is typicall for 48v nominal and will give you the largest range of compatible equipment to choose from.

Strongly suggest you get a BMS!!! Batrium makes specific 'mons' (monitors) for leaf modules - https://support.batrium.com/article/122-leafmon that bolt on nicely. Here's a youtube from Batrium showing how it works:

I run 2 Batriums and can help answer specific questions if you get that far :)

Should I go alter the range of charging to the battery’s?

Thanks
Dave
 
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