Marine starting battery comparison
Century Marine Pro 680 vs 780: Boat Battery Comparison
The Marine Pro 780 has higher published starting ratings and reserve capacity, but it is 45mm longer and 4.1kg heavier than the 680. Choose the model that meets your engine's requirements and fits the boat's approved mounting arrangement; the larger number alone is not a fitment recommendation.
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
Century Marine Pro 680
NS70M MF / 133101
Consider the 680 if it meets the engine maker's specified ratings and your tray suits the smaller case. Preserve the correct polarity, terminal arrangement and secure restraint.
Option 2
Century Marine Pro 780
N70ZM MF / 133102
Consider the 780 if its higher ratings are required or useful and the longer, heavier case can be accommodated. Check clearance and mounting before ordering an upgrade.
Battery specifications compared
Manufacturer-published figures, checked 2 October 2026. Missing or contradictory details are identified explicitly.
| Specification | Century Marine Pro 680 | Century Marine Pro 780 |
|---|---|---|
| Exact model | NS70M MF / 133101 | N70ZM MF / 133102 |
| Application | Starting and semi-cycling | Starting and semi-cycling |
| Rated voltage | 12V | 12V |
| Rated capacity | 75Ah at the 20-hour rate | 100Ah at the 20-hour rate |
| CCA at −18°C | 680A | 780A |
| MCA at 0°C | 880A | 1000A |
| Published reserve capacity | 155 minutes | 180 minutes |
| Dimensions (L × W × H) | 260 × 171 × 202mm; 225mm total height | 305 × 171 × 202mm; 225mm total height |
| Weight | 21.0kg | 25.1kg |
| Terminals | Twin; polarity D in manufacturer diagram | Twin; polarity D in manufacturer diagram |
| Published warranty | 24 months; conditions apply | 24 months; conditions apply |
Century Marine Pro 680: The brochure gives starting and semi-cycling specifications. Check the engine maker's battery requirements and the actual tray, restraints and terminal orientation; engine horsepower alone is not a fitment approval. Check manufacturer details ↗
Century Marine Pro 780: The brochure gives starting and semi-cycling specifications. Check the engine maker's battery requirements and the actual tray, restraints and terminal orientation; engine horsepower alone is not a fitment approval. Check manufacturer details ↗
Australian prices and quote checks
Century Marine Pro 680
Current price not verified
The manufacturer brochure does not provide a retail price. Request a quote for the exact item number, including delivery and any fitting charge.
Check price source ↗Century Marine Pro 780
Current price not verified
The manufacturer brochure does not provide a retail price. Request a quote for the exact item number, including delivery and any fitting charge.
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.
CCA and MCA: compare the same rating
Cold cranking amps and marine cranking amps are measured at different temperatures. Compare CCA against CCA, and MCA against MCA. Comparing one battery's MCA with another's CCA makes a false advantage appear in a shopping table.
Use the engine manual's requirements rather than a horsepower-only rule. If it specifies a particular battery type, minimum reserve or capacity as well as starting current, all those conditions matter. Neither a battery name nor this comparison overrides the engine manufacturer's instructions.
Will a Marine Pro 780 fit in a 680 battery tray?
The published width and total height match, but the 780 is longer. Measure the usable tray, the restraint positions, cable reach and access opening. A shared width does not mean the same hold-down or box will work, and connections must not be pulled tight to reach a different terminal position.
The weight increase also matters when lifting the battery into a confined compartment. Plan safe access and secure mounting rather than relying on loose packing. Confirm the actual replacement against the brochure's item number and terminal diagram before fitting.
Reserve capacity is not a fridge-runtime promise
The 780's published reserve figure is higher, but reserve-capacity minutes refer to a defined test rather than your boat's collection of loads. Fridges, lights, pumps and sounders produce a different demand pattern. Preserve enough starting reserve instead of treating the entire rating as a house-bank allowance.
Century positions these models for starting and semi-cycling. If you need repeated overnight accessory use, assess whether a separate house battery is appropriate for the boat. That is a system decision, not a reason to assume the larger starting battery solves every energy problem.
Common battery comparison questions
Is the Marine Pro 780 a direct replacement for the 680?
Not automatically. It is longer and heavier, and the engine requirements, terminal layout, restraints and clearance must all be checked.
Are the prices in this comparison current?
No retail price is stated for these models because a current quote was not verified. Ask for the exact item number and a delivered or fitted total.
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.
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.