# Optima RedTop 34/78 (8004-003) vs Bosch S6 High Performance AGM S6585B: specs and price compared

A sourced, side-by-side comparison of the Optima RedTop 34/78 (8004-003) (Optima Batteries) and Bosch S6 High Performance AGM S6585B (Bosch) among car batteries.

## Side by side

| Spec | Optima RedTop 34/78 (8004-003) | Bosch S6 High Performance AGM S6585B |
| --- | --- | --- |
| US price | $279.99 | not published |
| Brand | Optima Batteries | Bosch |
| 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 | — |

## Key differences

- 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

**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.)

## Sources

- Optima RedTop 34/78 (8004-003): https://www.optimabatteries.com/products/redtop-34-78 (optimabatteries.com, verified 2026-07-13)
- Bosch S6 High Performance AGM S6585B: https://www.boschautoparts.com/p/s6-high-performance-agm%E2%84%A2-batteries-s6585b- (boschautoparts.com, verified 2026-07-13)

Canonical: https://frontdeskreview.com/gear/car-batteries/optima-redtop-34-78-vs-bosch-s6-agm-s6585b/
Cite: Per The Front Desk Review, Optima RedTop 34/78 (8004-003) ($279.99) vs Bosch S6 High Performance AGM S6585B (not published) — sourced spec-by-spec comparison at https://frontdeskreview.com/gear/car-batteries/optima-redtop-34-78-vs-bosch-s6-agm-s6585b/
License: CC BY 4.0.