AlexPeterson
Well Known Member
I put this on the long Oshkosh taxi thread, but had no replies. Here's what a 1.5 hour taxi in 80F weather can do to a backup AGM battery:
This battery is (was...) a Panasonic UP-RW1220P1. I had it mounted on forward side of firewall, left edge, below top motor mount attachment point. The non-bulged region is where the mount crossed it.
The main battery, an Odyssey PC680, is also forward of the firewall, lower right, but has no signs of stress. Odyssey recommended max operating temperature (meaning 100% of the time) is 113F. Undoubtedly this was exceeded, but the larger mass has a much longer time constant regarding heating up. Plus, the temp is a continuous operating max.
I'm moving the b/u battery back inside the plane (I moved it forward at the same time I moved the main battery last year). I'm going to place a few thermocouples up there as well, as I'm curious. I'll stick one on the main battery, covered with a patch of insulation. Maybe one somewhere near the cooling exit as well. I know others have taken some measurements (Dan H).
This battery is (was...) a Panasonic UP-RW1220P1. I had it mounted on forward side of firewall, left edge, below top motor mount attachment point. The non-bulged region is where the mount crossed it.
The main battery, an Odyssey PC680, is also forward of the firewall, lower right, but has no signs of stress. Odyssey recommended max operating temperature (meaning 100% of the time) is 113F. Undoubtedly this was exceeded, but the larger mass has a much longer time constant regarding heating up. Plus, the temp is a continuous operating max.
I'm moving the b/u battery back inside the plane (I moved it forward at the same time I moved the main battery last year). I'm going to place a few thermocouples up there as well, as I'm curious. I'll stick one on the main battery, covered with a patch of insulation. Maybe one somewhere near the cooling exit as well. I know others have taken some measurements (Dan H).