Nissan Leaf BMS

Here we collect information about Nissans BMS.

Connectors

Credit goes to Wolftronix for figuring this out.

P4 24 pin				P3 32 pin				P6 16 Pin				P5 40 Pin
Pin	Cell	Cell	Pin	Pin	Cell	Cell	Pin	Pin	Cell	Cell	Pin	Pin	Cell	Cell	Pin
1	1		13	1	21		17	1			9	1	61	60	21
2	3	2	14	2	23	22	18	2	49	48	10	2	63	62	22
3	5	4	15	3	25	24	19	3	51	50	11	3	65		23
4	7	6	16	4	27	26	20	4	53	52	12	4	67	64	24
5	9	8	17	5	29	28	21	5	55	54	13	5	69	66	25
6	11	10	18	6	31	30	22	6	57		14	6	71	68	26
7	13	12	19	7	33	32	23	7	59	56	15	7	73	70	27
8	15	14	20	8		34	24	8		58	16	8	75	72	28
9		16	21	9	35	36	25					9	77	74	29
10			22	10	37	38	26					10	79	76	30
11	17	18	23	11	39	40	27					11		78	31
12	19	20	24	12	41	42	28					12	81	80	32
				13	43	44	29					13	83	82	33
				14	45	46	30					14	85	84	34
				15	47	48	31					15	87	86	35
				16	49		32					16	89	88	36
												17	91	90	37
												18	93	92	38
												19	95	94	39
												20	97		40

CAN Messages

Upon powerup the unit spits out messages that contain various useful info. After a while these messages stop and you have to send 50B#00 00 00 C0 00 00 00 to get it going again.

To get the individual cell voltages, first issue 79B#02 21 02 FF FF FF FF FF. You will receive the first reply looking like this: 7BB#10 C6 61 02 0E C9 0E C0.

Now send 27 times 79B#30 01 00 FF FF FF FF FF and you get 7BB#21 0E C0 0E C2 0E C0 0E. It is one index byte and 7 data bytes. So after 28 messages you will have collected 98 words (16-bit) of data. Every other message it stretches over to the next message. The first and the last byte are unknown so we discard them. That leaves us with 97 Words. It looks much like Word 1-96 are the 96 individual cell voltages and word 97 is the total pack voltage.