08 · Chemistry
AGM vs lead-acid vs lithium
Four chemistries cover the entire passenger-car market: flooded lead-acid, EFB, AGM, and lithium. They differ on lifespan, price, weight, charge speed, and cold performance. The cost-per-year column at the bottom is the buying decision most guides skip.
Comparison Table · 8.1
The full spec sheet
Flooded Lead-Acid
SLI- Lifespan
- 3 to 5 yrs
- Price
- $80 to $150
- Weight
- 30 to 50 lbs
- CCA
- Good
- Maintenance
- Periodic on non-sealed
- Vibration
- Fair
- Charge
- Slow (8 to 10 hr)
- Self-discharge
- 5% / month
- Cold perf
- Drops sharply below 20°F
- Warranty
- 12 to 36 mo free
- Best for
- Standard cars without start-stop
- Cost / year
- $22 / yr
EFB
Enhanced Flooded- Lifespan
- 4 to 6 yrs
- Price
- $90 to $160
- Weight
- 30 to 50 lbs
- CCA
- Good
- Maintenance
- None (sealed)
- Vibration
- Good
- Charge
- Moderate (6 to 8 hr)
- Self-discharge
- 3% / month
- Cold perf
- Better than lead-acid
- Warranty
- 24 to 36 mo free
- Best for
- European start-stop systems
- Cost / year
- $25 / yr
AGM
Absorbent Glass Mat- Lifespan
- 4 to 7 yrs
- Price
- $120 to $300
- Weight
- 30 to 50 lbs
- CCA
- Very good
- Maintenance
- None (sealed)
- Vibration
- Excellent
- Charge
- Fast (3 to 5 hr)
- Self-discharge
- 1 to 2% / month
- Cold perf
- Good
- Warranty
- 24 to 48 mo free
- Best for
- Start-stop, heavy electrical loads
- Cost / year
- $30 / yr
Lithium (LiFePO4)
Li-ion- Lifespan
- 8 to 10 yrs
- Price
- $400 to $800
- Weight
- 8 to 15 lbs
- CCA
- Excellent
- Maintenance
- None
- Vibration
- Excellent
- Charge
- Very fast (1 to 2 hr)
- Self-discharge
- Less than 1% / month
- Cold perf
- Reduced; some need warmer
- Warranty
- 36 to 60 mo free
- Best for
- Performance, weight-sensitive
- Cost / year
- $67 / yr
The math
Cost-per-year, the buying-decision column
Lead-acid wins on cost-per-year for most drivers. AGM wins for stop-start vehicles or anyone running heavy electrical loads (winches, sound systems, frequent short trips). Lithium is for performance and weight-sensitive applications, not value.
Lead-acid: $100 ÷ 3.5 yrs = $28.57 / yr
EFB: $125 ÷ 5 yrs = $25.00 / yr
AGM: $200 ÷ 5.5 yrs = $36.36 / yr
Lithium: $600 ÷ 9 yrs = $66.67 / yr
Decision guide
Which type do you actually need?
Standard car, no start-stop
→ Lead-acid
Modern car with start-stop (badge in dashboard)
→ AGM (or EFB)
European compact with start-stop
→ EFB
Performance or track build, weight matters
→ Lithium
Truck or SUV with winch / lights / inverter
→ AGM
Daily driver, short commutes, city only
→ AGM (deeper cycle tolerance)
Continue your research