Batteries recharging from an Atomic 4

[shellback]

Hello all,

I have dual, Type 24 batteries in my Oday 27. I bought the boat in September 2006. The boat comes with an Atomic 4 30hp engine.

I'm new to inboards and how much running of the engine will recharge the batteries. However, how long would I have to run my engine to recharge the batteries, given the type of engine and batteries I have on my boat.

FYI - the batteries are stored in a tight space beneath the port quarter berth...can't fit in type 27's.. (which I'd prefer).

[By Invitation]

Your engine has very little to do with this question. We need to know the size and output of your alternator, how discharged your batteries are and at what RPM you run your motor to charge them. As you can see, there are several variables and no cut and dry answer. Your best bet is to install a simple battery monitor which will indicate the status of your battery bank, your charging rate and percentage of charge at all times.

[Sonosailor]

You need to know how many amp-hours you took out after they were full, and how many amps your alternator can put in. You will have some losses due to wire and battery resistance, some other basic inefficiencies, and you will also have the decrease in amps from your alternator as you approach "full", making it difficult and inefficient to get back to being "topped up".

Solar panels are a great way to do the last topping up, by the way, as they provide amperes at a slow rate, use free fuel, and are unlikely to overcharge.

[Rick]

If you deplete the capacity by 10% or more they are considered to be "deeply discharged" and you will never recover the capacity properly on a cyclical basis without having a regulator capable of reaching 14.4 V, prefereably a 3-step charge regulator. Your "automotive" type regulator will not do that.