Back to Mercedes-Benz for service
According to Roadtrek, idling charges the Roadtrek E-trek battery at a rate of 2000 watts at 24 volts @ 1000 RPM. On Friday, August 7th, we ran down the batteries from 85%/25 VDC to 20%/21 VDC to see if we could fully charge the batteries by idling. We started the test at 11:00 AM when the battery was at 85%/25 VDC. Then we turned on the battery disconnect, inverter, and AC with the temperature set at 60 degrees F. After one hour, the battery was at 65%/23 VDC. After two hours, the battery was at 50%/23 VDC. After three hours, the battery was at 20%/21 VDC and the CO alarm was beeping, indicating low battery, so we turned off the AC.
As a reminder, according to Roadtrek:
- Full charge…..25.5 volts
- Moderately depleted…..24 volts
- Adequately charged…..23.5 volts and above
- Minimum charge ……21 volts
After revving the engine and idling, we noticed that the battery did not display 100% as it should, but rather 83%/24 VDC. Karl moved it around the driveway, but the battery stayed at 83%/24 VDC. When the battery went down to 68%/23 VDC after 30 minutes of idling, we sensed something was wrong. Karl popped the hood and noticed right away the fan wasn’t spinning. He turned off the engine and took a closer look. Sure enough, it looks as though the belt had slipped off again.
It was late Friday afternoon, so we immediately contacted Mercedes-Benz to see if we could drop it off so they could take a look at it as soon as possible. Karl spoke to the same technician who had serviced the E-trek in May, who will look at it first thing Monday morning and change the oil as well.
Unknown, since we could not complete the test. To be continued…