Marine starting battery comparison
Optima BlueTop D31M vs Century Marine Pro 1000
The Marine Pro 1000 lists higher starting ratings and Ah capacity; the Optima D31M is an AGM model in a narrower case. They differ in construction and intended application, so the larger figures alone do not establish a better choice for every boat.
Specification-based comparison. We have not bench-tested these models. Prices are dated observations, not live offers. Read the manufacturer sources and editorial policy.
Which battery should you shortlist?
Option 1
Optima BlueTop D31M
D31M / Australian product ID 139352
Shortlist D31M when its AGM specification and narrower case fit the engine, charging and accessory requirements of the installation.
Option 2
Century Marine Pro 1000
86M MF / 135104
Shortlist Marine Pro 1000 when its higher published starting ratings are required and the wider, taller case fits with correct restraints.
Battery specifications compared
Manufacturer-published figures, checked 2 October 2026. Missing or contradictory details are identified explicitly.
| Specification | Optima BlueTop D31M | Century Marine Pro 1000 |
|---|---|---|
| Exact model | D31M / Australian product ID 139352 | 86M MF / 135104 |
| Application | AGM marine starting and accessory use | Starting and semi-cycling |
| Rated voltage | 12V | 12V |
| Rated capacity | 75Ah | 100Ah at the 20-hour rate |
| CCA at −18°C | 900A | 1000A |
| MCA at 0°C | 1125A | 1200A |
| Published reserve capacity | 155 minutes (supplier RC figure; test conditions to confirm) | 180 minutes |
| Dimensions (L × W × H) | 324 × 165 × 237mm; 237mm total height | 330 × 172 × 218mm; 242mm total height |
| Weight | 27.1kg | 25.0kg |
| Terminals | Twin; check supplier diagram | Standard / wing nut; check diagram |
| Published warranty | 36 months in Australian supplier listing; conditions apply | 24 months; conditions apply |
Optima BlueTop D31M: Figures follow the Australian distributor's D31M listing. Overseas D31M documents can show slightly different dimensions and mass; match the actual supplied unit and terminal drawing rather than mixing specifications from several markets. Check manufacturer details ↗
Century Marine Pro 1000: Marine Pro 1000 is the 86M MF model. The 1000 in its name refers to its CCA rating, not amp-hour capacity. Check the engine manual rather than treating generic horsepower marketing as fitment approval. Check manufacturer details ↗
Australian prices and quote checks
Optima BlueTop D31M
Current price not verified
The Australian distributor specification page does not quote a selling price. Request a local quote for product ID 139352 and check warranty coverage.
Check price source ↗Century Marine Pro 1000
Current price not verified
Ask for a delivered or fitted quote for Century item 135104. No retail price is published in the cited specification source.
Check price source ↗Source links on this page are direct references, not affiliate tracking links. Compare delivered prices on the same day and obtain a separate scope for installation, charging changes and protection.
Start with the engine and accessory requirements
The cited Australian listings give different starting and capacity figures. Compare CCA with CCA and MCA with MCA; do not use the Optima MCA number against the Century CCA number to declare a winner.
The D31M is sold as an AGM marine battery. Whether that construction suits the proposed application depends on the charging requirements, mounting instructions and intended usage. This page does not contain a controlled cycling test between the two products.
Group names do not guarantee identical fit
The Australian D31M listing is narrower than the Marine Pro 1000 listing, but its mass is greater. Measure the actual restraint and terminal positions. A familiar case-group label is not enough to establish an interchangeable installation.
Overseas Optima documents can list slightly different dimensions and mass. This table follows the Australian distributor's product ID so it does not combine the most convenient figures from different markets. Confirm the dimensions of the supplied unit before purchase.
Compare local support and written warranty terms
The Australian distributor lists different headline warranty periods for these products. Check exclusions and the permitted application, and ask who handles assessment locally. A longer advertised period is not a measured prediction of service life.
Neither source supplies a verified current retail price for this comparison. Obtain equivalent delivered or fitted quotes. If repeated accessory discharge is the main concern, assess the battery arrangement rather than assuming a premium starting battery removes the need to manage reserve.
Common battery comparison questions
Which has the higher published CCA?
Marine Pro 1000 lists 1000A CCA; the Australian D31M listing gives 900A CCA.
Is the D31M the lighter option?
Not in the cited Australian listings: D31M is 27.1kg and Marine Pro 1000 is 25.0kg.
Sources and comparison method
We matched the exact model codes to the manufacturer documents below on 2 October 2026. The selection advice is our interpretation of those specifications. We have not measured capacity, durability, waterproofing or service quality. We do not turn manufacturer cycle claims into a tested lifespan ranking.
- Century Yuasa: Australian Optima D31M specifications ↗
- Optima Australian range brochure ↗
- Century 86M MF official specifications ↗
- Century Australian marine range brochure ↗
Specifications, offers and warranty terms can change. Match the supplied unit to its current manual before purchase. Report a correction with the model code and source.