You could use, but may be the charging is low.
3,5 hr is OK.
Newly Bought Soundcore Motion+
That sounds slow so probably it’s giving 5V 1A which is the safest default USB charge. The speaker wants 5V 1.65A so a 5V 2A charger would be faster.
Other chargers you own may do 5V 2A so try others. I’d not recommend buying a charger just for this need but example Anker charger doing 5V 2A is