Left Segway i2 Uncharged, Swapped Batteries now E042 Error

[h_s]

Hello,

I left my Segway i2 (with around 200 miles) unplugged for eight months or so. (I now know that was a bad idea.) I then tried to plug it in but the rear battery gave a red light. I read on a forum that unplugging it and plugging it in may make that go away, as well as leaving it charging for a day. I got the red light to go away but the rear battery would still not charge. I swapped the batteries and now I am able to turn the Segway on but I get the E042 error. What do you recommend doing for my next steps? Would a new battery solve the issue?

Thank you in advance.