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LTC4015 not charging

Category: Hardware
Product Number: LTC4015

Dear technical team,

I am running some test for an own designed PCB using LTC4015. Everything looks fine, but the system is not able to charge batteries.

SYSTEM SPECS:

1) 12 cell lead acid configuration.

2) VIN = 29V

3) Rsnsi = Rsnsb = 3 miliohm

4) Stand by batteries voltage = approximately 26V

I am trying to run a charge test routine setting a voltage charge of 27.8 and a max current of 1A. Below I pasted the 74 register data for the LTC4015:

Address Hex Dec/Eng Unit
1 0x0 0
2 0x0 0
3 0x0 0
4 0x0 0
5 0x0 0
6 0x0 0
7 0x0 0
8 0x0 0
9 0x0 0
10 0x0 0
11 0x0 0
12 0x0 0
13 0x0 0
14 0x0 0
15 0x0 0
16 0x0 0
17 0x0 0
18 0x0 0
19 0x0 0
20 0x10 16
21 0x2F 47
22 0x0 0
23 0x0 0
24 0x0 0
25 0x0 0
26 0x2 2
27 0x1A 26
28 0x889 2185
29 0xFFFF 65535
30 0x0 0
31 0xFFFF 65535
32 0xFFFF 65535
33 0xFFFF 65535
34 0xFFFF 65535
35 0xFFFF 65535
36 0xFFFF 65535
37 0xFFFF 65535
38 0xFFFF 65535
39 0xFFFF 65535
40 0xFFFF 65535
41 0x0 0
42 0x8 8
43 0x1518 5400
44 0x0 0
45 0xFFFF 65535
46 0xFFFF 65535
47 0x0 0
48 0x0 0
49 0x0 0
50 0x0 0
51 0x0 0
52 0x200 512
53 0x0 0
54 0x0 0
55 0x0 0
56 0x0 0
57 0x22C7 8903
58 0x4239 26.08 V
59 0x44D9 29.05 V
60 0x44C6 29.01 V
61 0x21 0.016 A
62 0x67 0.05 A
63 0x3609 39.9 °C
64 0x2A70 9893 Ohm
65 0x0 0 Ohm
66 0x1 1
67 0x88C 2188
68 0x2 1 A
69 0x22 27.89 V
70 0x2F 8 A
71 0x4235 16949
72 0x0 0 A
73 0x0 0
74 0x1 1

Based in the status, system indicates a state of "absorb_charge", but power is not delivered. The measured voltage on the board is the same voltage reported for telemetry (shown in previous table)

During development phase, some I2C registers were written randomly. After that I re write them. For that reason some register has the value 0xFFFF. However I understand that registers are not used in lead acid mode.  

Thanks in advance