Re: Alternator Question
1988 Mercruiser Alpha 350
I have upgraded and added alot of the electronics on my boat and added a second battery. I am begining to worry about the strain I am putting on my OEM alternator. Is it possible to upgrade to a bigger unit? If so, do I have to use a marine part or can I substitue an automotive style? Thanks.
What sort of electronics did you add?
Take each of the components that you added. look up the current requirements and add them all together. You probably have a 65A alternator on the boat. Unless you have ALL of your stuff on at the same time (all the time) you're probably not really stressing your alt.
You might need to consider the recharge current required by the battery(s) when being recharged after a start..... It's usually high momentarily but tapers off quickly. You wouldn't normally have all the electronics on at that time.
If by electronics, you mean a fish finder, GPS, stereo..... those are items that probably draw less than 5A each... If you have an inverter powering a microwave oven.....you're talking a serious current draw..(don't try that by the way unless you have 2 or 3 BIG batteries in parallel)
It's a simple job to get an ammeter and measure what each item requires for current too.... A lot of modern electronic devices draw less than 3 A or so.
Your starter and trim pump are the largest current draw in the boat but they don't run all the time and the battery is usually what powers those.....
Chances are you're not straining your alt at all....
Cheers,
Rick
