After our E-trek was returned to us on October 2nd, we performed some follow-up testing detailed below and summarized in Etrek-Battery-Log-October
Test #1 (10/3/15)
In our post titled Welcome Home, E-trek! we discussed the charging by driving test we did the day after the E-trek was returned to us (October 2nd, 2015). While the battery did charge on the drive, we experienced a malfunction with the Webasto resulting in a fault message of six red pulses. According to the Webasto manual, this indicates “overheating or exceeding gradient water temperature.” The remedy was to turn off the Webasto for 5 seconds, then turn it back on, which worked.
The 70-mile round trip charged the battery from 86%/25 Volts to 96%/26 Volts, so the charging while driving is working. We also verified that the serpentine belt was secure.
Test #2 (10/4/15)
Since the nights were starting to get cold, we wanted to test the effect of the Webasto heater to make sure we could run it without draining the batteries. On Sunday, October 4th, we turned on the Webasto (heat with hot water production) at 6:15 AM. At that time the battery was at 86%/25 Volts. We checked it periodically, and after five hours, it was at 85%/25 Volts.
The Webasto appears to have a minimal effect on the battery life, and is probably being offset by the charging provided by the solar panels.
Test #3 (10/5/15)
Monday was just a periodic battery check to see if the solar panels were working. The battery was at 87%/25 Volts at 7AM. By 11AM the battery was at 90%/25 Volts, and by 4PM the battery was fully charged at 94%/26 Volts.
The solar panels are now properly charging the batteries.
Test #4 (10/6/15)
Tuesday we decided to test the battery charging by idling. At 7AM the battery was at 89%/25 Volts. We left the engine idling for about an hour, which should be enough time to restore the batteries to 26 Volts, which according to Roadtrek is “fully charged.” After stopping the engine, the battery was at 98%/27 Volts.
The charging by idling was successful.
Test #5 (10/7-8/15)
Our final test was to plug in to shore power to see if the batteries would (1) charge to 100% and (2) if the solar panels could maintain the batteries. Before we plugged into 20 AMP shore power, the battery strength was at 89%/25 Volts (7AM). By 9:45 AM the battery was at 95%/26 Volts, but after that it fell to 91%/25 Volts at 11:45 AM and never got above 92%/25 Volts. We checked the connection and left it plugged in overnight; however, it was still at 92%/25 Volts at 7AM on the following day.
Charging by shore power increased the battery to 98%/26 Volts by 11:30 AM. After unplugging from shore power, the battery strength % started decreasing; however, it did maintain 26 Volts, which according to Roadtrek is “fully charged.”
All of the results of our latest round of testing are detailed in Etrek-Battery-Log-October.