Ok lets try and fill you guys in with some data.
the Batteries as I understand it are 3.75v cells and there are two types of cells I have.
1 Cell as 15v capacity of 4 cells at 3.75v x 4 = 15v I will call this the large battery
the next battery is a 1/2 battery and it just that.. 2 cells made up of 3.75v = 7.5v
I have in total 4 large batteries
and I have 2 1/2 batteries
My calculations using the wha rating all 6 batteries give me 8kw
1/2 a pack ... 2 large 1 of the 1/2 batteries gives me 4kw
I hope to run the cityel on the one half
and the mini el on the other half
The amp hour rating for the large battery is 108ah and the 1/2 size battery 55ah
there is a circuit board on the battery but I would ignore that.. as i feel that it would be more hassle than it is worth..
I will need to some how get a BMS made up so that the discharge cuts the power when it gets to 3v per cell and the same the other way when it charges to 4.1v or a max of 4.2v
I understand the basics needed on paper to protect and prolong the life of the batteries
but sadly that is where my knowledge stops.. I feel if any one has an ideas how I can go forward that would really help.. I think I need to get a simple BMS that I can connect up and monitor each cell..
Now... there is a small issue but i think it's best ignored in favour of I think others have had the same problem..
I said there are 4 cells to a large battery that is correct ... how every they are in series? ( I hope I got that right ) there are in fact 3 smaller cells to each bigger cell... so to make up one cell of the 4 in the large battery... there are infact 3 small cells.. to that one..
so to be really accurate there are 12 small cells to one large battery.. I think to monitor all 12 cells on one BMS would start to over complicate things and I am best just ignoring that and going for a BMS that monitors the 4 larger cells to 1 large battery...
does that make sence?
Cooling.. well I could add fans but I think being as it's a small car with open air to the batteries and really not needed but .... I could add fans later if when working I can see that I need to keep the temp down..
take a look at this listing to show you more details.. this is for the large battery .. I have 4 of these..
it shows the spec and you can see from the one photo that the battery is formed of 12 smaller cells..
http://rover.ebay.com/rover/1/710-5...0001&campid=5338536215&icep_item=293734777987