(ET) PTO and low pack voltage

[john rieffel <rieffelj union edu>]

I vaguely recall that there is some circuit that prevents the PTO from
switching on with low pack voltages.  Is this correct?  My backup E-15
seems to lose PTO earlier than my original, and it seems that the
batteries still have plenty of juice in them.   (My alternate's Fuel
gauge also seems to read much lower voltages than my original - even
fully charged (confirmed by handheld meter) it never reads more than
1/3 into the green.  Could these two be related?

jr