Yes, interestingly. Earth X Battery. Can't imagine how this would affect things though, as nominal bus voltages haven't changed.
This may be a good place to start ... my guess (without any research or knowledge of your setup) is that swapping battery types is throwing off your calibrations .. Lithium (especially LiFE) are different animals. They act like a traditional battery but are very different. LiFE (lithium iron phosphate) for example hold a constant voltage until it's fully discharged then drops off radically.
If you still have your old battery or a similar one, maybe hook it up and see what the readings show.
Hope you find the issue!