It is spring and time to get the 07 Roadtrek ready for our spring trip. Last October I charged the 618ah, 12v, lithium bank to my monitor reset point with the shore charger and then just left it sit with the charger in "silent" mode where it would do a charge cycle if the voltage got down to 13.0v. It didn't run at all from October to about April one when I unplugged it. The monitor showed 68% SOC that I know is high because it doesn't see the battery parasitic loads. It was out in the sun for a while after that so went up some after that.
I don't do a full capacity test every year like Winston does so my information is not as accurate an indication of the battery condition, but enough to tell enough at this point.
Starting point was indoors at 67*.
Voltage was 13.13v
Battery SOC on monitor showed 69.9%
Cell balance between all 12 cells in the 3 batteries within .0001v
Charged off shore power to my arbitrary 80% full point where the charger shuts off
After 30 minutes the voltage was at 13.29v
After 30 minutes the SOC showed 94% so went up about 14% due to parasitic loss over the winter and charge efficiency now
After 30 minutes the 12 cells were within .0006v
After 15 hours the voltage was 13.26v
The state of charge at 80% as I reset it from 94%
Cell balance was within .0002v
These readings are essentially identical to what I got last spring so don't seem to have lost anything substantial to this point.
This is as expected as the batteries have been carefully charged and are not aged much yet. IIRC Winston said his behaved similarly in the early years.
I do expect to start losing capacity at about 7-8 years old as that seems to be where most well designed system start to age out.
Our batteries are getting very few alternator charges now and maybe 2 shore charges a year. The solar keeps up on most trips without any other charging and is set to hold in midrange SOC of about 50-70%.
Performance of the system has been as expected, except for the shore power inverter/charger failure last year. We use all AC power with the 3K inverter and never plug in. We use the microwave, Instant pot, curling iron, computer, device charging, TV, etc but don't run the air conditioning on batteries. We do have a compressor frig and average daily use is in the 50-80ah range unless it is very hot and then we can get to 100ah per day running 3 fans and frig using more power in the heat. There is 300 watts of solar on the roof.
I don't do a full capacity test every year like Winston does so my information is not as accurate an indication of the battery condition, but enough to tell enough at this point.
Starting point was indoors at 67*.
Voltage was 13.13v
Battery SOC on monitor showed 69.9%
Cell balance between all 12 cells in the 3 batteries within .0001v
Charged off shore power to my arbitrary 80% full point where the charger shuts off
After 30 minutes the voltage was at 13.29v
After 30 minutes the SOC showed 94% so went up about 14% due to parasitic loss over the winter and charge efficiency now
After 30 minutes the 12 cells were within .0006v
After 15 hours the voltage was 13.26v
The state of charge at 80% as I reset it from 94%
Cell balance was within .0002v
These readings are essentially identical to what I got last spring so don't seem to have lost anything substantial to this point.
This is as expected as the batteries have been carefully charged and are not aged much yet. IIRC Winston said his behaved similarly in the early years.
I do expect to start losing capacity at about 7-8 years old as that seems to be where most well designed system start to age out.
Our batteries are getting very few alternator charges now and maybe 2 shore charges a year. The solar keeps up on most trips without any other charging and is set to hold in midrange SOC of about 50-70%.
Performance of the system has been as expected, except for the shore power inverter/charger failure last year. We use all AC power with the 3K inverter and never plug in. We use the microwave, Instant pot, curling iron, computer, device charging, TV, etc but don't run the air conditioning on batteries. We do have a compressor frig and average daily use is in the 50-80ah range unless it is very hot and then we can get to 100ah per day running 3 fans and frig using more power in the heat. There is 300 watts of solar on the roof.
