Battery Health 101 · 1 / 9 · The idea
Why SOH isn't the whole story
'State of health'
is not health.
One number can't describe a living system.
SOH is one input, not the verdict
2 / 9 · What SOH measures
State of Health · SOH
87%
usable capacity ÷ original capacity
SOH = remaining capacity, as a percentage
3 / 9 · The blind spots
Power & resistance
how hard it can push
Safety trend
cells drifting to fault
Thermal history
heat it has seen
Cell balance
weakest-cell risk
Charge habits
fast / deep cycling
Future trajectory
where it's heading
One number, six blind spots
4 / 9 · Same number, different battery
Pack A · 87% SOH
Healthy
- Full power
- Runs cool
- Cells balanced
Pack B · 87% SOH
At risk
- Power sags
- Runs hot
- High resistance
Identical SOH can hide very different health
5 / 9 · The safety gap
→
⚠️
One cell drifting
toward a fault
→
🚫
SOH can't see it
capacity ≠ safety
Capacity says nothing about safety
6 / 9 · A snapshot, not a forecast
SOH reads the dot. It can't tell you which branch comes next.
SOH is today — not tomorrow
7 / 9 · What real health takes
Many signals, read together and projected forward — into one score.
Many signals, read together
8 / 9 · One weak signal can't hide
The worst signal should set the tone
9 / 9 · The takeaway
SOH is an input.
Health is the score.
BattHealthScore™ combines every signal into one predictive number — inside EVCare.
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