Just a bit confused - Nissan Leaf Solar battery set up
- Thread starter Erzferz
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Ampster
Renewable Energy Hobbyist
Perhaps your BMS was set to LFP instead of NMC so that is what misled you and never allowed your batteries to get a full charge. Or, as you said, you have never charged your batteries. Did you read the manual on the BMS?
Just trying to figure out how to add power to this system so I can continue to try and set everything correctly, should I buy a trickle charger? Or just plug in the inverter, and turn it on, see if that will charge the system, I am just worried the voltage of my cells are quite low and something in my system could be damaged.
Any direction for this would be so helpful.
Any direction for this would be so helpful.
Ampster
Renewable Energy Hobbyist
No worries, your cells are already quite low. If you do not put a load on them you should be able to charge them. Set your BMS to the correct voltage for your cells and charge from solar or a power supply. You have six modules connected in a configuration that your BMS will see as four cells. The max voltage should be 4.15 per cell. Reread this thread, the correct advice is all here. Some time ago someone told you to charge your pack. That seems to be the advice that was not followed before putting a load on your batteries. The BMS misled you because it was set for a chemistry that was not the chemistry you are using. Those Nissan Leaf modules are NMC.
Ok, I really appreciate the help here, I honestly spend a lot of time rereading this thread and others, trying to understand more. It feels like maybe I just don't know what to ask or where to look for the right answers most of the time.
I will go try to set and save the parameters for the BMS to charge each cell to 4.15. and the system to 16 and the chemistry to NMC
But this also leaves me with another question I asked before and am not sure i understand anymore now.
How does one get these numbers or values? each Nissan leaf module is supposed to be 7.6v, but now i am setting each cell to 4.15v- wouldn't that mean these cells would never be charged?
And if each is 14.15 would that then mean my batteries need to reach atleast 16.6v to be fully charged?
If i set these parameters in the BMS do i still have to top balance my cells? Do i need to buy a cell balancer to do this?
I will go try to set and save the parameters for the BMS to charge each cell to 4.15. and the system to 16 and the chemistry to NMC
But this also leaves me with another question I asked before and am not sure i understand anymore now.
How does one get these numbers or values? each Nissan leaf module is supposed to be 7.6v, but now i am setting each cell to 4.15v- wouldn't that mean these cells would never be charged?
And if each is 14.15 would that then mean my batteries need to reach atleast 16.6v to be fully charged?
If i set these parameters in the BMS do i still have to top balance my cells? Do i need to buy a cell balancer to do this?
Ampster
Renewable Energy Hobbyist
The chemistry determines the voltages. Researching the chemistry which you have, will give you the numbers. Nissan Leaf modules can be confusing because they consist of two pairs of cells in series. You need to be clear about whether you are talking about when you use a term. The cells level, the module level or the pack evel. The chemistry will determine the cell level voltage for any battery of the same chemistry. The 7.6 number you may have seen is the nominal value which translates to 3.8 per cell nominal voltage. Nominal voltage is like the resting voltage of a cell after it is charged.
I am not sure I understand why you think charging a cell to 4.15 volts would mean anything other than what it does. That translates to 8.3 volts per module and to 16.6 volts per pack.
Yes that is exactly what that means if you are referring to the entire pack? What are you referring to when you say, "each"? The pack, the module or the cells?
The parameters in the BMS are the points where you want something to happen to protect your individual cells. There are many settings, but most of them apply to cell level voltages. You will also need to set your charger to a voltage setting for the pack.
Your cells are probably well balanced so lets only worry about that if your BMS is telling you that there are big differences between the cells.
Thank you Ampster, That does clarify a few things for me. I didn't have any idea honestly that battery chemistry played such a role.
As foolish as it may sound I have been reading about and researching trying to understand so many little parts of this for longer than I want to admit. Electricity scares me to a degree, my personal electrical knowledge prior to this project was zero. Admittedly I was completely naïve to what any of this system would really entail when I took it on.
I have felt fairly overwhelmed by the immense information that's out there, and the lack of knowledge on my own part.
Although at least somethings are making a bit more sense, but I'm curious about a few things still,
That first number should be able to represent how many Ah total my entire pack has, Total Battery Capacity was preset for 100Ah so 100000mAh.
The number above is just a general one, but I have somewhere just over 46ah in each of the six battery modules- if I use exact numbers multiply by the number of modules wouldn't that give me my actual AH total, that I could input there?/ Is everything i do not change to exactly match my battery, will that then just go along with whatever I do change and set, or should I be figuring out every setting on here to be exact?
These are all the values I have just gone through and changed.
And after i finalize and save that i will go hook up, turn on the inverter, change the charging parameters to, Lithium user battery and it says in its manual the highest setting range is 15.5v- I am just curious is this is going to make my batteries lack a full charge?
I really appreciate the help all, thanks again
As foolish as it may sound I have been reading about and researching trying to understand so many little parts of this for longer than I want to admit. Electricity scares me to a degree, my personal electrical knowledge prior to this project was zero. Admittedly I was completely naïve to what any of this system would really entail when I took it on.
I have felt fairly overwhelmed by the immense information that's out there, and the lack of knowledge on my own part.
Although at least somethings are making a bit more sense, but I'm curious about a few things still,
That first number should be able to represent how many Ah total my entire pack has, Total Battery Capacity was preset for 100Ah so 100000mAh.
The number above is just a general one, but I have somewhere just over 46ah in each of the six battery modules- if I use exact numbers multiply by the number of modules wouldn't that give me my actual AH total, that I could input there?/ Is everything i do not change to exactly match my battery, will that then just go along with whatever I do change and set, or should I be figuring out every setting on here to be exact?
These are all the values I have just gone through and changed.
And after i finalize and save that i will go hook up, turn on the inverter, change the charging parameters to, Lithium user battery and it says in its manual the highest setting range is 15.5v- I am just curious is this is going to make my batteries lack a full charge?
I really appreciate the help all, thanks again
Ampster
Renewable Energy Hobbyist
I would set the start balancing voltage at 4.0 volts, trigger at 4.2 and release at 4.1. Do you have a spec sheet for those modules to check what they recommend the max voltage should be to verify my recommendation? That way you can own it.
The percentage charge numbers tell your BMS what percentage to report and the current entries are for the wrong chemistry, which is why you thought your battery was full when it was empty. Full is 4.2 volts when charging and resting at 3.9. and empty about 2.75 volts to be safe. Find a discharge chart and fill in your guess where 60 40 and 20 might be. The battery is stupid, it will not "fall in line" based on what values you set.
Again, a discharge chart will tell you what charging your cells to only 3.875 volts per cell (15.5 divided by 4) could be as low as 50 to 60 percent of your capacity. It all depends on how your charger is configured and how long it continues to charge after it reaches 15.5 volts. That may be a setting in you charger. It is usually called absorb setting and be adjusted by time or amperage. You should spend time reading your inverter manual to see if you can charge to a higher voltage somehow or you will not be getting much capacity out of your batteries.
The percentage charge numbers tell your BMS what percentage to report and the current entries are for the wrong chemistry, which is why you thought your battery was full when it was empty. Full is 4.2 volts when charging and resting at 3.9. and empty about 2.75 volts to be safe. Find a discharge chart and fill in your guess where 60 40 and 20 might be. The battery is stupid, it will not "fall in line" based on what values you set.
Again, a discharge chart will tell you what charging your cells to only 3.875 volts per cell (15.5 divided by 4) could be as low as 50 to 60 percent of your capacity. It all depends on how your charger is configured and how long it continues to charge after it reaches 15.5 volts. That may be a setting in you charger. It is usually called absorb setting and be adjusted by time or amperage. You should spend time reading your inverter manual to see if you can charge to a higher voltage somehow or you will not be getting much capacity out of your batteries.
Ampster
Renewable Energy Hobbyist
Ill reach out to where I bought the Nissan modules tomorrow and see if I can get a discharge chart from them.
Ill also call renogy to see if someone can help me get more in depth with this inverter. I see it has USER option up to 15.5 and ill hope higher. Under its Maximum utility charging says 65A witch if supplied at 1080W would be 16.61V. But like you had said maybe there is some absorption mode that will charge higher, or for long enough - i did see a mention for absorption charge at14.4/14.8
My solar charge controller from EPever says it is ok to program it up to 17v so that should ideally be capable of topping off the batteries.
I will likely have to see if there is a way to shut off the renogy over voltage protection, if it cannot go above 16vdc +- .3vdc.
Am I almost better off trying to find and use a 24v programmable inverter?
Or different battery bank set up all together?
This is really eye opening thank you so much.
Ill also call renogy to see if someone can help me get more in depth with this inverter. I see it has USER option up to 15.5 and ill hope higher. Under its Maximum utility charging says 65A witch if supplied at 1080W would be 16.61V. But like you had said maybe there is some absorption mode that will charge higher, or for long enough - i did see a mention for absorption charge at14.4/14.8
My solar charge controller from EPever says it is ok to program it up to 17v so that should ideally be capable of topping off the batteries.
I will likely have to see if there is a way to shut off the renogy over voltage protection, if it cannot go above 16vdc +- .3vdc.
Am I almost better off trying to find and use a 24v programmable inverter?
Or different battery bank set up all together?
This is really eye opening thank you so much.
Ampster
Renewable Energy Hobbyist
I think it was mentioned earlier that the voltage of 2 Nissan Leaf modules is hard to work with. Only you would know what you have invested and what it would be easier to start over with.
Either change out the batteries for a 12 Volt system to use your existing inverter and or charge controller. A 24 volt inverter would mean a new BMS and reconfiguring your batteries. Based on the difficulty you have had in the past 45 days I think that could be more confusing. Only you can answer that question.
Yes, though even with that information I believed just having USER options for the components would let me adjust that, and only now am I really understanding how difficult these batteries are to work with, there are so very few components that can function on the voltages these produce.
I just read a bit into using a "buck converter/ boost converter" to obtain the actual voltage I need - This also seems like an increasingly complicated route to go.
Just got off the line with Renogy- thats the end to the USER parameters,15.5V is the max. And there is no way to turn off overvoltage protections so this inverter wouldn't even work when my battery pack was fully charged.
Not quite sure how I want to go about this yet.
Would you or anyone have any recommendations for Lithium batteries I could wire up with the 4s BMS I have?
If I was to use regular Lithium Iron Phosphate it should be somewhere just over 14V to fully charged, this would be ok for just about everything in lithium mode compared to these Nissan Modules that need very specific programming for everything.
If I'm not mistaken my total battery pack as is would be capable of somewhere around 270AH capacity. Based on 46AH a module.
Ill start trying to look into other types of batteries out there but it would be ideal if I could find ones to create a battery pack with at least 200AH or more capacity.
I just read a bit into using a "buck converter/ boost converter" to obtain the actual voltage I need - This also seems like an increasingly complicated route to go.
Just got off the line with Renogy- thats the end to the USER parameters,15.5V is the max. And there is no way to turn off overvoltage protections so this inverter wouldn't even work when my battery pack was fully charged.
Not quite sure how I want to go about this yet.
Would you or anyone have any recommendations for Lithium batteries I could wire up with the 4s BMS I have?
If I was to use regular Lithium Iron Phosphate it should be somewhere just over 14V to fully charged, this would be ok for just about everything in lithium mode compared to these Nissan Modules that need very specific programming for everything.
If I'm not mistaken my total battery pack as is would be capable of somewhere around 270AH capacity. Based on 46AH a module.
Ill start trying to look into other types of batteries out there but it would be ideal if I could find ones to create a battery pack with at least 200AH or more capacity.
Ampster
Renewable Energy Hobbyist
There are several threads about EVE, Lishen and CALT batteries in that range of Ahrs. A good starting point would be Amy at Luyuan. I had used Nissan Leaf modules in a 48 volt configuration for years with none of those issues. It is just the difficulty of integrating them into products that work at 12 volts nominal. I bought EVE LF280 cells but they may be in shorter supply than when I bought. As far as size, since you have the opportunity, now would be a good time to think about your needs in terms of capacity. I find it easier to think in terms of Watts and Watthours instead of Amps so get comfortable with the terms.
These are all really good recommendations and extremely helpful. I have found a number of things using some of your direction incredibly clarifying.
I think for right now, I will go with other batteries for this system, I need it running.
Though its very interesting seeing how these Leaf Modules get used for a lot of 48v systems, even adding another leaf would use a 14s setup in series and would be easier to use for something along those lines, out of sheer curiosity how many modules were you running in that set up you mentioned?
I have not entirely made any decisions but I did check into a lot of the cells you suggested and really liked the EVE LF280 cells, though from what I can tell they tend to take a bit of time to ship overseas.
It does seem like the many of the most affordable batteries on the market are overseas. This is huge- what an interesting online market place to explore.
I think two terminal batteries seem so much easier for me to wrap my head around as well. And frankly reading about and watching standard LFP batteries wired with a BMS actually makes sense to me! (For the most part)
Another type of cell that actually caught my eye as well were these Fortune Cells mentioned by Will Prose. They have quite a slick appearance, although not nearly as cost affordable. It did get me thinking though, my 4s BMS would be great for either 4 cells or even 8 cells where I have them setup in 4 pairs of two parallel cells.
Everyone here has been very helpful, with everything on this thread, especially because being "just a bit confused" was clearly an understatement.
Haha Very sincere thanks to all, I think to avoid being entirely off topic, and to make things more concise, I will begin a different thread in the near future with whatever cells I decide to go with.
I think for right now, I will go with other batteries for this system, I need it running.
Though its very interesting seeing how these Leaf Modules get used for a lot of 48v systems, even adding another leaf would use a 14s setup in series and would be easier to use for something along those lines, out of sheer curiosity how many modules were you running in that set up you mentioned?
I have not entirely made any decisions but I did check into a lot of the cells you suggested and really liked the EVE LF280 cells, though from what I can tell they tend to take a bit of time to ship overseas.
It does seem like the many of the most affordable batteries on the market are overseas. This is huge- what an interesting online market place to explore.
I think two terminal batteries seem so much easier for me to wrap my head around as well. And frankly reading about and watching standard LFP batteries wired with a BMS actually makes sense to me! (For the most part)
Another type of cell that actually caught my eye as well were these Fortune Cells mentioned by Will Prose. They have quite a slick appearance, although not nearly as cost affordable. It did get me thinking though, my 4s BMS would be great for either 4 cells or even 8 cells where I have them setup in 4 pairs of two parallel cells.
Everyone here has been very helpful, with everything on this thread, especially because being "just a bit confused" was clearly an understatement.
Haha Very sincere thanks to all, I think to avoid being entirely off topic, and to make things more concise, I will begin a different thread in the near future with whatever cells I decide to go with.
Ampster
Renewable Energy Hobbyist
I ran six modules mostly because of the even number of modules I had on hand. My inverter could have handled seven but instead of buying more modules, I converted to new LFP cells.
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