Inverter/charger stuck in "bulk" and never finishing

A charger that stays in bulk stage indefinitely and never progresses to absorption/float is either seeing a load that's still pulling more current than the charger can overcome, or the battery itself has a problem preventing it from reaching the voltage threshold to transition stages. Try disconnecting all loads temporarily and see if it progresses — if it does, you've found a load issue; if it still won't transition, the battery or charge settings need a closer look.