What I used: twin batteries both the same size.
Minimum 450cca. I used 650 or 800cca even 1000cca.
The bigger the longer they last when the boat has lots of 12v accessories
#4 or #2 wire with good copper connectors.
Using a deep cycle battery on an outboard can potentially cause issues with the charging system if not managed carefully, but it's not a guaranteed problem. Deep cycle batteries are designed for sustained power delivery, not the high current bursts needed for starting. Using them to start an engine frequently can lead to premature wear and potential damage over time. Additionally, some deep cycle batteries require specific charging profiles (like
AGM batteries requiring 15V) that standard outboard charging systems might not provide, potentially leading to incomplete charging.
- Damage to charging system:
In extreme cases, the high current draw from a deep cycle battery during engine start, combined with inadequate charging, could potentially stress or damage the outboard's charging system, especially if the battery is significantly discharged before starting.
When it's more likely to be a problem:
- Cold weather starting:
Deep cycle batteries generally have lower cold cranking amps (CCA) than dedicated starting batteries, making them less suitable for starting in cold conditions.
- Frequent engine starts:
Repeatedly using a deep cycle battery to start a cold engine can put a strain on both the battery and the charging system.
- Incompatible battery types:
If the deep cycle battery is not designed for marine use or doesn't have proper charging characteristics for the outboard's system, it could lead to problems.
Recommendations:
- Use a dual-purpose battery:
If you need a battery that can handle both starting and deep cycle loads, consider a dual-purpose marine battery designed for both purposes.
