SignatureSolar has stated things in regards to warranties/service exchange methods previously, regarding open vs closed loops.
Remember, this thread? You made a few posts in it yourself. Granted, they were talking about 3rd party open loop batteries in that situation, but any chargers other than the inverter are likely to not be in the loop of the inverter and battery and thus relying on "open loop" methods.
I find it best to have everything laid out in the open warranty wise, to avoid gotchas and take backs later.