Your 3 phase charger can be rewired internally to run on single phase power input. The number of phases a charger is set to run on has nothing to do withe the ability to delivery a charge to a lift truck battery. The charger receives AC (Alternating Current)voltage from the outside power supply (utility pole) and the AC power is converted via transformers inside the charger to DC (Direct Current) so it can charge the battery. A charger that runs on AC power input will be easier on you power bill than a single phase. But the biggest issue you must verify is to be certain your battery and charger are properly matched - the battery has a rating of XXXX amp/hrs the charger must be capable of supplying XXXX amps (within = or - 5%) over the charge cycle which is about 6-8 hours, depending on how discharged a battery is.
Any local & reputable battery supplier can help you with this. conversion and matching compatbility of the charger to the battery & some (not all) can help you get the charger wired up to you power supply (make certain they are licensed to do so for you protection - safety inspection & liability issues).