I've read that there can be damage to the ignition system when running a mercury outboard on a low battery. I have a few threads going right now to address certain issues but this one is specifically regading running my 86 45 hp on a weak battery?
Re: What is at risk when running an outboard on a low battery
The battery is only used to start the motor. The only issue I can see is you are stuck somewhere unable to start the engine unless you have a pull cord.
Re: What is at risk when running an outboard on a low battery
Actually the bigger risk is burning up your stator. When your battery is low, the current going to your battery will be higher which can shorten the stator's lifespan.
Re: What is at risk when running an outboard on a low battery
Mercurymang is accurate. As the voltage drops the current it will try to pull from the stator will increase. It might be wise if you're able, to disconnect and temporarily tape off one of the stator's feeds to the rectifier until you replace the battery, which will mean that it is not charging the battery.
