Ford think Extended range Lithium battery packs

Does anyone know if converting a Ford think to Lithium requires any mods for the 12V DC converter to operate? I just installed a 72V 60Ah pack (built in BMS) and as soon as I turned the key to the on position, a poof came from under the hood. After checking the DC converter with a DMM, I’m getting 79V coming in but nothing coming out. Curious if the battery blew the converter. For context, I just purchased this Think so I’m not sure if the converter would have gone out with OEM style batteries.