Battery Ah to CCA Calculator
Convert Battery Ampere-Hours (Ah) to Cold Cranking Amps (CCA) and vice versa.
Ah to CCA Calculator
Approximate Conversions
Results:
Calculated CCA: 0.00
Calculated Ah: 0.00
How to Use the Calculator
Convert Ah to CCA
- Select "Ah to CCA" using the radio button.
- Enter the Ampere-Hours (Ah) value in the input field.
- The Cold Cranking Amps (CCA) will be automatically calculated and displayed.
Convert CCA to Ah
- Select "CCA to Ah" using the radio button.
- Enter the Cold Cranking Amps (CCA) value in the input field.
- The Ampere-Hours (Ah) will be automatically calculated and displayed.
Reset
- Click the "Reset" button to clear all input fields and results.
- This will also reset the calculator to the default "Ah to CCA" mode.
How to Convert Ah to CCA and CCA to Ah
Use the industry-average 7.25 multiplier as a quick bridge between energy capacity and cold-cranking performance.
1. Capture Battery Details
Record the rated amp-hour capacity, chemistry (flooded, AGM, lithium), and intended use (starting vs. deep-cycle).
- Check if the rating is at 20-hour or 10-hour discharge.
- Note ambient temperature expectations.
2. Pick the Direction
Decide if you are estimating cranking performance from capacity (Ah → CCA) or inferring capacity from a published CCA value.
- Starting batteries: usually CCA first.
- Solar/RV banks: typically Ah first.
3. Apply the Formula
The calculator uses a 7.25 factor derived from typical automotive starting batteries.
- CCA = Ah × 7.25
- Ah = CCA ÷ 7.25
4. Validate & Adjust
Compare the estimate with manufacturer data, temperature derating, or load testing.
- High-performance batteries may exceed the ratio.
- Old or cold batteries may deliver less CCA.
5. Formula & Real-Life Example
Apply the 7.25 multiplier and sanity-check with field values.
- Formulas: CCA = Ah × 7.25, Ah = CCA ÷ 7.25
- Example (delivery van): 95Ah AGM battery ⇒ 95 × 7.25 ≈ 689 CCA, which matches the OE 700 CCA spec.
- Reverse Example (marine starter): 850 CCA outboard battery ⇒ 850 ÷ 7.25 ≈ 117 Ah of usable capacity.
Ah to CCA & CCA to Ah Chart
Approximate conversions using the 7.25 multiplier (values rounded to the nearest 5 CCA or 0.1Ah).
Ah → CCA Reference
| Amp-Hours (Ah) | Estimated CCA |
|---|---|
| 35 Ah (powersport) | ~255 CCA |
| 55 Ah (compact car) | ~400 CCA |
| 75 Ah (mid-size car) | ~545 CCA |
| 100 Ah (truck / RV) | ~725 CCA |
| 150 Ah (dual bank) | ~1,090 CCA |
| 200 Ah (large RV) | ~1,450 CCA |
CCA → Ah Reference
| Cold Cranking Amps (CCA) | Estimated Ah |
|---|---|
| 300 CCA | ~41.4 Ah |
| 450 CCA | ~62.1 Ah |
| 600 CCA | ~82.8 Ah |
| 750 CCA | ~103.4 Ah |
| 900 CCA | ~124.1 Ah |
| 1,100 CCA | ~151.7 Ah |
Always verify with manufacturer data when available—these conversions assume healthy 12V lead-acid batteries near room temperature.
Battery Ah to CCA FAQs
Quick answers to the most common conversion questions.
How to convert battery Ah to CCA?
Multiply the amp-hour rating by 7.25 to estimate the Cold Cranking Amps. For example, 80Ah × 7.25 ≈ 580 CCA. This ratio comes from typical automotive starting batteries and provides a fast sanity check.
How do you calculate CCA from Ah?
Use the formula CCA = Ah × 7.25. Plug in the amp-hour capacity at the standard 20-hour rate, apply the factor, and round to the nearest 5–10 CCA. For greater accuracy, consult the datasheet because plate design and chemistry affect the true CCA rating.
How many CCA is a 100Ah battery?
Applying the converter gives 100Ah × 7.25 = 725 CCA. Premium AGM or lithium starting batteries may advertise higher numbers, while older flooded batteries might deliver slightly less.
How many CCA is a 200Ah battery?
A 200Ah 12V battery equates to roughly 1,450 CCA using the 7.25 factor. Large deep-cycle banks often prioritize capacity over cranking amps, so check the manufacturer’s spec sheet if you intend to use them for engine starting.
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