Maybe... the current won't be as clean as a dedicated power supply. We did this in the old days when using NiCads.. they were a lot less fussy than delicate LiPo batteries.

Best advice is to contact the maker of your charger.. they will probably not recommend it if using such a power source would damage the charger or cause it to malfunction.

You can get a new or used power supply in the neighborhood of $40-$50. I have had some over the years that have gone through several generations of chargers..

Good luck!

Jerome