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Part of my reason for doing that is I am tired of hearing the usual banter that batteries are more expensive than the grid. That may be true in many cases. It all depends on where you are standing. Of course that implies understanding the total cost of ownership of batteries and the rate structure. .......
I got a lot of good ideas from that video. I would have done some things differently but most of those are style or process issues. I will articulate them below in an effort to add to the knowledge base about pack assembly.
I agree sanding the battery terminals and connecting buss bars is important. I do that with 3M non conductive material that tends to leave less grit. I blow off the terminal threads anyway to make sure there is nothing on the inside threads. I also use NoAlox to prevent any oxidation or other reactions between the aluminum and copper. I only use it on the conducting surfaces and not on the threads. I have traditionally used copper buss bars that are a lot of work. I read on another forum that someone used Aluminum buss bars and they would have to be sized accordingly because Aluminum has less current carrying capacity than copper. I am going to research resistance before I make a decision. I also notice that he used studs and nuts. That may be because of the different thickness of his connection pieces and so he could make sure the studs had as much thread connection as possible. In my past pack assemblies I have just used two different length bolts depending on the thickness of the pieces being joined.
The orientation of the prismatics is an issue that the Nissan Leaf modules don't seem to care about since they are in the car horizontally. I have always mounted my prismatics with the terminals up since the ones I have used in the past always had a bleed valve. I will do more research before I decide but there are a lot of advantages to having them horizontal especially in a cabinet. The first one is that one could use different length buss bars for all the series connections. That is what Nissan does with the pack in the Leaf. I know it was a pain making buss bars but my hydraulic crimper is also a pain and time consuming and doing all those interties seems uneccessary when you could use one buss bar across the middle because the distances are all small. Another advantage of that horizontal mounting of the batteries is that the terminals are accessible. That make it easy to check the nuts and measure voltage if you are getting erratic readings from your BMS. Depending on the layout it could also mean you would not need longer interconnects between rows of vertically mounted cells. There are challenges about strapping the cells whether they are horizontall or vertical but I will deal with that if it comes up at inspection. I still might need to wait a year to make the correct assessment of my capacity needs so I have some time to think about those details.
As I mentioned earlier, I have only used prismatics in plastic cases. I did notice that he used plastic separators and insulated his cabinet. i will be interested what the manufacturer recommend or if there is any detectable voltage between the case and either of the terminals.
btw - here is another YT that leverages this cell form factor in a Craftsman cabinet. https://www.youtube.com/watch?v=xlxM-BcIxWE
I agree sanding the battery terminals and connecting buss bars is important. I do that with 3M non conductive material that tends to leave less grit. I blow off the terminal threads anyway to make sure there is nothing on the inside threads. I also use NoAlox to prevent any oxidation or other reactions between the aluminum and copper. I only use it on the conducting surfaces and not on the threads. I have traditionally used copper buss bars that are a lot of work. I read on another forum that someone used Aluminum buss bars and they would have to be sized accordingly because Aluminum has less current carrying capacity than copper. I am going to research resistance before I make a decision. I also notice that he used studs and nuts. That may be because of the different thickness of his connection pieces and so he could make sure the studs had as much thread connection as possible. In my past pack assemblies I have just used two different length bolts depending on the thickness of the pieces being joined.
The orientation of the prismatics is an issue that the Nissan Leaf modules don't seem to care about since they are in the car horizontally. I have always mounted my prismatics with the terminals up since the ones I have used in the past always had a bleed valve. I will do more research before I decide but there are a lot of advantages to having them horizontal especially in a cabinet. The first one is that one could use different length buss bars for all the series connections. That is what Nissan does with the pack in the Leaf. I know it was a pain making buss bars but my hydraulic crimper is also a pain and time consuming and doing all those interties seems uneccessary when you could use one buss bar across the middle because the distances are all small. Another advantage of that horizontal mounting of the batteries is that the terminals are accessible. That make it easy to check the nuts and measure voltage if you are getting erratic readings from your BMS. Depending on the layout it could also mean you would not need longer interconnects between rows of vertically mounted cells. There are challenges about strapping the cells whether they are horizontall or vertical but I will deal with that if it comes up at inspection. I still might need to wait a year to make the correct assessment of my capacity needs so I have some time to think about those details.
As I mentioned earlier, I have only used prismatics in plastic cases. I did notice that he used plastic separators and insulated his cabinet. i will be interested what the manufacturer recommend or if there is any detectable voltage between the case and either of the terminals.
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