Funny this came up today . I was going ot post about this if I had a chance. I spoke to parent company of Energie Cycles in Vegas. The tech I spoke to estimated starting at 300 for 10 amp and up to 500 or more for maybe 16 amp , depending on a few items. He had not specifically done a Stormer. He was looking at the web to gather as much info as he could while we spoke.
Based on the BMS still being good and saw the shape but has not seen the inside, including the cells. He will send a Haz Mat shipping label or as I suggested if I can remove the old cells before supping the case would be better. Site is blocked at work so best i can do is post this phone number, 888-546-9419
ask the questions, may get a different phone number. I spoke to a tech that was their Haz Mat and battery tech , didn't get his name , nice guy , eager , give them a call and report back for all
. I told him I was not in a hurry . I have a few batteries and also n not sure I will use this until out of warranty, just to be sure but so far the best I have found and a great start
from another thread , has the correct info