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Optima Batteries
Optima RedTop 34/78 (8004-003)
$279.99
Best Car Batteries · head-to-head
Optima RedTop 34/78 (8004-003) vs Bosch S6 High Performance AGM S6585B
A sourced, side-by-side comparison. Optima RedTop 34/78 (8004-003) is cheaper at $279.99. Every spec and price links to its source.
Which is better: the Optima RedTop 34/78 (8004-003) or Bosch S6 High Performance AGM S6585B?
The Optima RedTop 34/78 (8004-003) wins 1 of the 1 specs we compare head to head; the other wins 0.
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Full spec sheet
✓ marks the stronger figure where "more" — or "less", for price and weight — is unambiguously better.
| Spec | Optima RedTop 34/78 (8004-003) |  Bosch S6 High Performance AGM S6585B |
|---|---|---|
| US price | $279.99 | — |
| Brand | Optima Batteries | Bosch |
| Released | — | — |
| Battery type | spiral-wound-AGM | AGM |
| Bci group size | 34/78 | 48/H6 |
| Cold cranking amps | 800 | 760 |
| Cranking amps ca | — | 875 |
| Reserve capacity min | 100 | 120 |
| Capacity ah | 50 | 70 |
| Terminal type | dual | top-post |
| Weight (lb) | 38.8 | 45.5 |
| Warranty months | 36 | 48 |
| Maintenance free | Yes | Yes |
| Dimensions inches | 10.06 x 6.94 x 7.88 | — |
Sources — Optima RedTop 34/78 (8004-003): optimabatteries.com (verified 2026-07-13). Bosch S6 High Performance AGM S6585B: boschautoparts.com (verified 2026-07-13).
What's the difference between the Optima RedTop 34/78 (8004-003) and Bosch S6 High Performance AGM S6585B?
Where the two actually differ on the specs we track (8 of 11). Matching specs are omitted.
- Battery type: Optima RedTop 34/78 (8004-003) spiral-wound-AGM vs Bosch S6 High Performance AGM S6585B AGM
- Bci group size: Optima RedTop 34/78 (8004-003) 34/78 vs Bosch S6 High Performance AGM S6585B 48/H6
- Cold cranking amps: Optima RedTop 34/78 (8004-003) 800 vs Bosch S6 High Performance AGM S6585B 760
- Reserve capacity min: Optima RedTop 34/78 (8004-003) 100 vs Bosch S6 High Performance AGM S6585B 120
- Capacity ah: Optima RedTop 34/78 (8004-003) 50 vs Bosch S6 High Performance AGM S6585B 70
- Terminal type: Optima RedTop 34/78 (8004-003) dual vs Bosch S6 High Performance AGM S6585B top-post
- Weight (lb): Optima RedTop 34/78 (8004-003) 38.8 vs Bosch S6 High Performance AGM S6585B 45.5
- Warranty months: Optima RedTop 34/78 (8004-003) 36 vs Bosch S6 High Performance AGM S6585B 48
What reviewers say
Sourced tester consensus for each — the "what people who used it think" layer, not just specs.
Optima RedTop 34/78 (8004-003)
Only one whitelisted tester covers this battery. Pro Tool Reviews names the Optima RedTop its best-value AGM pick, praising reliability, longevity and vibration resistance while flagging a lower CCA rating than pricier rivals. This is a qualitative buying-guide verdict for the RedTop line (which includes the 34/78), not a bench test of the 8004-003, and no whitelisted outlet published measured lab numbers for this exact model. (1 sourced review.)
Praised: Best-value AGM pick — reliable and worth the price premium; Spiral-cell design resists vibration and outlasts standard lead-acid; 3-year replacement warranty, widely available in-store and online.
Flagged: Lower CCA rating than competing AGM batteries; Heavy-electronics or auto stop-start vehicles need the pricier YellowTop; More expensive than standard lead-acid batteries.
Bosch S6 High Performance AGM S6585B
No sourced tester review yet.