Sorry to hear it — a deep discharge from a dead-short event (those burnt key contacts) is one of the nastier ways for a battery to go down, because the BMS often latches into a protection state and won't come back on its own.
Here's the honest situation with your 2019 Levo FRS (M1-50 / U1-style 700Wh pack on the original Brose 2.0 system):
Three flashing LEDs = a fault/protection code, not a charge state. On the Specialized packs of that era, a flashing pattern like that is the BMS telling you it's in a fault lockout — most commonly an over-discharge / cell-undervoltage lockout, exactly what a deep discharge causes. The cells reading good voltage doesn't clear it; the BMS has to be told the fault condition is resolved.
What actually unlocks it:
• If the BMS dropped into
deep-sleep / undervoltage lockout, the recovery is a specific wake/reset sequence done through Specialized's service tooling (the dealer-level diagnostic, not Mission Control / BLEvo). A consumer charger generally
will not wake a latched BMS — which is exactly what you're seeing: cells fine, no charge accepted.
• A genuine
Specialized Service Centre can read the BMS fault log and, in many cases, perform the reset/re-wake. This is the cleanest route and worth a call first.
The complication you should know about: the
1st-gen Levo/Kenevo packs had a safety recall issued 30 August 2022 —
@Zimmerframe flagged this on here (
→ view post). Because of that recall, some dealers are reluctant to service or "revive" these original packs at all, and a heat/short event (your burnt keys) is precisely the failure mode the recall was about. So even if the cells are healthy, a shop may decline to reset it on safety grounds. Don't take that personally — it's a liability thing, not your fault.
What I'd do, in order:
1. Ring a Specialized dealer, quote the recall, and ask if they'll read/reset the BMS.
2. If they won't touch it, a reputable independent battery rebuilder can sometimes reset or re-cell the BMS — but vet them, given the short history.
3. I'd be cautious about DIY-jumping the BMS awake; on a pack that's already had a thermal event, that's a real fire risk and not worth it.
I can't responsibly walk you through forcing the BMS open myself — on a post-short pack that's genuinely dangerous.
If you can tell me the exact LED colour/flash pattern and whether the charger LED does anything when plugged in, I can help narrow down which fault state it's in.
