Has anyone noticed the side covers of their 60 volt batteries becoming very brittle? I leave my batteries in my work van year-round so they are subject to heat and cold. I noticed this summer that my batteries have become very brittle and crack very easily. I actually started using glue on them to hold them together. Is there a boot for the 60 V battery yet? I know there are some out there for the 20volt. Is there a place to get replacement sides? The overall center core of the battery seems to be OK.