Hey mate, sorry for slow reply. I have been plagued with issues. We could not resolve, so now i have a fully independent system and just leave the 2 batteries for crank only, i do not use any auxiliary ports now.
Short summary-
- Secondary (factory-fitted) battery consistently healthy, holding ~13.3V and recharging normally.
- Primary battery began showing reduced SOC over time, no longer holding above ~80%, now capped at ~70% or below.
- Charge rate remains low (1–4A) even at low SOC, indicating the vehicle's charging system isn't recognising the deficit.
- Battery voltage drops immediately after external charging — surface charge only, not holding a true full charge.
- External smart charger (direct connection, 24hr+ cycles) provides the only meaningful improvement, temporarily lifting voltage to ~12.9V.
- After any normal use, battery returns to sub-70% SOC and will not recover through driving alone.
- Dealer swapped battery positions with temporary improvement — issue returned within weeks.
- Issue has been raised with dealer on multiple occasions but we cannot resolve.
- Functional impact is significant — reduced auxiliary power availability and roughly 50% reduction in useful off-road/away hours.
