How much will the solar panels replenish “moderately depleted” batteries?
On Tuesday we determined that the Roadtrek E-trek solar panels do not keep the batteries “topped up.” According to Roadtrek, “moderately depleted” batteries are 24 VDC. (see Roadtrek E-trek Solar Test I ) We want to see if it is possible for the solar panels to return them to a “fully charged” status, which is defined at 25.5+ VDC. Since the inverter displays only whole numbers, we will use 26 VDC as being fully charged.
On Wednesday morning, August 5th at 7:00 AM the battery was at 87%/25 VDC. We started the AC to drain the battery. When we checked the battery at 8:00 AM the battery was at 82%/24 VDC. By 10:30 AM the battery was at 68%/23 VDC, so we turned off the AC, battery disconnect, and inverter.
By 12:00 PM the battery was at 82%/24 VDC. At 2:00 PM the battery was at 84%/24 VDC. At 5:00 PM the battery was at 85%/25 VDC.
We continued logging the battery strength on Thursday. At 7:00 AM the battery was at 83%/24 VDC. By 11:00 AM the battery was at 84%/25 VDC. The battery strength peaked at 3:00 PM at 88%/25 VDC and then started to go down. According to Roadtrek, 25 VDC is considered “adequately charged.”
The Roadtrek E-trek solar panels can recover the batteries to an “adequately charged” status (23.5+, but will not reach “fully charged” status (25.5+) by solar alone.