BMV 712 smart monitor with progressive dynamics smart charger (PD4060). Only the coach battery connection, no temp or starter battery connected.
Lead acid 6V batteries.
Typically low usage, 1-5 AH, no usage higher than 5 AH.
Sometimes we have boondocked for a week or two and run the generator to charge when the battery got low. Often we are plugged into shore power.
I am seeing several readings that don't look accurate at all:
1) After boondocking 2-4 days depending on SOC, I run the generator to charge the batteries.
The BMV 712 shows running around 93/94 SOC and then instantly jumping to 100% state of charge. With lead acid I expect the SOC to take a very long time to top off (hours), not just jump to 100% instantly. What is going on here?
2) The SOC does not match the consumed amps or the voltage charts.
I understand the voltage drops when there is a load on it, yet our load is small so I would expect a small voltage drop.
I brought these up to the dealer early on and was told don't worry about it, you have low Ah usage so the battery lasts longer with that then it would if you used higher Ah usage - it is not a straight line. So trust the SOC.
Over time, these discrepancies seems worse.
Our battery is now showing signs it is failing which is unexpected for it's age (roughly 2 years old). I am concerned we have relied on the SOC following the dealers instructions when we should not have been.
Some examples:
2A)
80% SOC, current -3.1A
Consumed Ah -61 / 210 (71% left)
Voltage 12.26V (just above 60% in charts for lead acid)
2B)
62% SOC, current -1.3A
Consumed Ah -116 Ah (45% left)
Voltage 12.33v (65% roughly in charts for lead acid)
2C)
83% SOC, current -.3A
Consumed -52 Ah (75% left)
Voltage 12.73V (100% SOC in charts)
2D)
90% SOC, current -2.5A
Consumed -31 Ah (85% left)
Voltage 12.43V (below 80% SOC in charts)
2E)
95% SOC, current -1.3A
Consumed -18AH (91.4% left)
Voltage 12.37V (70% SOC in charts)
2F)
99% SOC, current -0.5A
Consumed -5 AH (97.6% left)
Voltage 12.58V (below 90% SOC in charts)
2G)
93% SOC
voltage current -1.1A
24 (of 210) consumed AH (would be closer to 88% SOC)
12.13 voltage (closer to 50% on charts).
Thanks for your help.
