What do you mean by "boosting the battery output voltage"?
A 44V open-circuit panel will be rated at a Vmppt of about 30V, meaning that when the current from the panel is such that the Panel voltage drops to ~30V (~ 8A for a 250W panel), the power out of the panel will be maximum. This would require a switch-mode charge controller that accepts inputs from ~24V to ~48V while delivering ~14V to your single battery.
Doing this brute force using a linear regulator would dissipate lots of power as heat in the regulator (will require a huge heat sink), and you will be wasting more than half of the available panel power.