VRLA / AGM Lead-Acid State of Health Calculator
SoH screening for VRLA / AGM Lead-Acid from age, cycles and DoD — chemistry-specific fade rates built in.
Sealed lead-acid is cheap and safe but shallow — design around 50% DoD and expect ~500 cycles; float life, not cycles, kills standby units. This SoH screen is pre-set to VRLA / AGM Lead-Acid fade characteristics — cycle rating, calendar fade and DoD sensitivity — so the estimate reflects how this specific chemistry ages rather than a generic battery curve.
SoH = 100% − cycle fade (20% × EFC ÷ rated cycles) − calendar fade (4.0%/yr for Lead-acid (VRLA/AGM)). Screening model — a measured capacity test (see the capacity-test tool) always beats an estimate.
Engineering estimate from published standards and typical equipment data. Site conditions, equipment datasheets and measured data govern the real result — confirm with a qualified engineer.
Use the free VRLA / AGM Lead-Acid State of Health Calculator online — SoH screening for VRLA / AGM Lead-Acid from age, cycles and DoD — chemistry-specific fade rates built in. Runs instantly in your browser: no signup, no upload, mobile-friendly.
About VRLA / AGM Lead-Acid State of Health Calculator
Sealed lead-acid is cheap and safe but shallow — design around 50% DoD and expect ~500 cycles; float life, not cycles, kills standby units. This SoH screen is pre-set to VRLA / AGM Lead-Acid fade characteristics — cycle rating, calendar fade and DoD sensitivity — so the estimate reflects how this specific chemistry ages rather than a generic battery curve.
How to use VRLA / AGM Lead-Acid State of Health Calculator
- 1Confirm the chemistry (the application default is pre-selected).
- 2Enter the battery's age, cycling rate and typical depth of discharge.
- 3Read estimated SoH, remaining cycles, and years until the 80% threshold.
Why use VRLA / AGM Lead-Acid State of Health Calculator?
- ✓Combines cycle wear and calendar aging — the two clocks every battery runs on
- ✓Chemistry-specific rates: LFP, NMC, lead-acid and more, not a generic curve
- ✓Depth-of-discharge stress modeled with the inverse-power law real datasheets follow
- ✓Years-to-80% forecast for replacement planning
Frequently asked questions
What does state of health (SoH) actually mean?+
SoH is today's usable capacity as a percentage of nameplate: a 100 Ah battery measuring 85 Ah is at 85% SoH. It declines through cycle wear (energy throughput) and calendar aging (time and temperature). 80% is the conventional end-of-life for most applications — usable, but with shrinking margins.
How accurate is an estimated SoH versus a real test?+
Estimation from age and usage lands within ±5–10% for typical duty — good for planning, not for warranty claims. A measured capacity test (full discharge at rated current) is the ground truth; use the estimate to decide when testing is worth the effort.
What degrades batteries fastest?+
Heat above 35°C (roughly doubles aging per 10°C), deep discharges (100% DoD can cost 3–4× the cycle life of 50% DoD), sustained full charge (calendar aging accelerates at high voltage), and fast charging when hot. Address the top one in your duty and lifespan visibly improves.
Is the VRLA / AGM Lead-Acid State of Health Calculator valid for my exact battery model?+
It uses chemistry-class parameters (cycle rating, calendar fade, DoD exponent) typical of quality cells. Premium cells beat the defaults somewhat; bargain cells underperform them. For fleet decisions, calibrate against one measured capacity test and the model tracks well after that.
Embed VRLA / AGM Lead-Acid State of Health Calculator on your website
Want VRLA / AGM Lead-Acid State of Health Calculatoron your own site? Paste this snippet into any HTML page — it's free, with no API key or sign-up. The tool loads in an iframe and keeps working exactly as it does here.
<iframe src="https://tooljolt.com/tools/agm-state-of-health-calculator" width="100%" height="640" style="border:1px solid #e5e7eb;border-radius:12px;max-width:680px" title="VRLA / AGM Lead-Acid State of Health Calculator — ToolJolt" loading="lazy"></iframe>Related tools
Related Energy tools
Rooftop Solar Calculator — Rajasthan
Estimate yearly kWh and bill savings from a rooftop solar system in Rajasthan using local irradiance (5.8 kWh/m²/day) and tariffs.
● LiveRooftop Solar Calculator — Gujarat
Estimate yearly kWh and bill savings from a rooftop solar system in Gujarat using local irradiance (5.6 kWh/m²/day) and tariffs.
● LiveRooftop Solar Calculator — Maharashtra
Estimate yearly kWh and bill savings from a rooftop solar system in Maharashtra using local irradiance (5.3 kWh/m²/day) and tariffs.
● Live