What you’re describing (brown sticky residue plus no charging) usually points to a battery or internal electrical fault, even if the main battery casing looks fine. It could be a battery management system leak, corrosion, or a damaged control board component. Either way, stop trying to charge it for now because it could get worse or become unsafe.
This often happens after prolonged storage, deep discharge, or exposure to moisture, where internal components degrade even if everything seems fine externally. The safest move is to have a technician inspect both the battery pack and the controller rather than attempt repeated charging cycles.
It’s a bit like an unstable VPN connection in a strict network environment. When the underlying system is unstable, forcing it won’t help much, and the real fix usually comes from addressing the root issue rather than retrying the same setup. That is why I chose options like these for better connectivity.
