Yes. Depending on charge voltage and how charged they actually are before you start, how long at CV and how long at float. And depending on how long they were discharged for and how deeply and depending on how quickly you are with your measurements! And depending on how accurate the meter is. And how long they were in a discharged state before recharging. Remember that many cheap meters can be a few tenths of a volt out...
So the charger could have been charging the batteries @ 28.8 but then went to a lower voltage or float @ 26.4. Then possibly the surface charge would be lower than actual battery charge level (depending on multiple other factors). Ok, I see how the surface charge could be higher or lower than actual charge. Thanks
The main reason I was worried about the 26.4v surface charge was because the documentation said you need to bring your batteries to full charge 28.2v to keep sulfates from building up. But it seems I have no way of knowing the actual charge level.
Thanks for sharing your time and knowledge.