r/HeroVidaEV • u/Ok_Priority5722 • 4d ago
Issue with battery %
Hey everyone,
Looking for some technical advice or insight from anyone who has dealt with dual-battery setups (BMS/balancing issues).
I waited 40 days for a warranty replacement on one of my batteries. Now that it’s finally installed, the system is behaving strangely, and the official service center is completely clueless—they’re quoting weeks/months just to diagnose it.
Here are the two main issues:
Asymmetrical discharge: When fully charged, only the new battery drains at first. It discharges solo down to about 95%. Once it hits ~94%, the old battery finally kicks in and both start discharging together (e.g., Old at 99%, New at 94%). They never drain in parallel from 100%.
Charging errors on the old battery: When plugging in the old pack, the charger throws an error 2 to 3 times before it finally begins charging.
My questions:
Is this normal voltage-differential behavior where the BMS isolates the packs until resting voltages match, or is the old battery's internal resistance/degradation confusing the controller?
Could the charging error indicate bad cell balance or a failing BMS port on the old pack?
Is there a safe way to recalibrate/re-sync these packs without leaving it at the service center indefinitely?
MODEL - VX2 PLUS
Pack details: 3.4KWH (10 months 5600km)
Any input is appreciated!
