Amp Power Question

[sarah.shepherd]

So what you're saying is that the problem is likely that the alternator cannot recharge the house battery fast enough due to being the stock alternator - correct?

I know you have mentioned the use of an ARC along with at perko or blue sea switch and we do not have one currently - should we consider adding one?

[sarah.shepherd]

Most of our boat use is camping for the weekend with no power source to plug into Saturday night so, if I understand the concept of an on-board charger correctly, an on-board charger wouldn't assist us during the weekend. It would just ensure that we had fully charged batteries before every trip - correct?

[chpthril]

So what you're saying is that the problem is likely that the alternator cannot recharge the house battery fast enough due to being the stock alternator - correct?

I know you have mentioned the use of an ARC along with at perko or blue sea switch and we do not have one currently - should we consider adding one?

The use of the ACR with still limit you output of the alternator and battery amp hours. The biggest plus from using an ACR is its and automatic may of isolating the starting and house batteries. The switch you have now does that, but manually.

Most of our boat use is camping for the weekend with no power source to plug into Saturday night so, if I understand the concept of an on-board charger correctly, an on-board charger wouldn't assist us during the weekend. It would just ensure that we had fully charged batteries before every trip - correct?

To increase the engine-off play time, you will need to build a larger battery bank. This adds to the complexity and a means to recharge this large battery bank once off the water is a must.

[sarah.shepherd]

We don't do a lot of engine-off play time to be honest - maybe a hour at a time and usually not more than 3 hours a day.

The other weekend when we had the issue it first did it when the engine was running. We were idling when it did it the first time but then even when we were riding we had the problem. We are testing the charge on the batteries currently to make sure they do hold a full charge.

[sarah.shepherd]

I pulled out our manuals and it looks like we do have a 55amp alt. I'm guessing to find out what alt. will work with our engine I need to call our local boat shop and have them look it up for us. I tried doing some quick googling but I would hate to order something that doesn't actually work with out 97 MerCruiser 5.7 engine ...

[sincity]

Those marine rated alternators are extremely expensive, over a 1,000.00 dollars for a 120amp, your best bet which works just fine, as chpthrll said, expand your battery bank, add a third battery, parellel two of the batterys together and connect them to one side of your battery switch, and the other battery by itself to the other side. use the parellel batteries for your stereo and the single as your house battery. make sure the parellel batteries are identical and as chpthrll said, if you fully charge them before you leave, they will last a long time. the stereo batteries should be good quality batteries, I have 6 year old optimas blue tops, i spent a week on lake powell and never switched over to batt 1, keep an i on your volt meter, if it gets down around 12 volts, turn your volume way down,or off and let the alternator charge em up, but if you have good quality batteries and leave the house with a full charge, around 13.8 volts, you shouldn't have a problem. at full volume, i'm pushing over 6,000 watts and never have had a problem with just two parallel batteries. 500.00 bucks for two new batteries would be cheaper than the new alternator.i also found that if you take the 12 volt feed for the the head unit and run it directly back to the battery, it will eliminat any alternator noise, it did in my case anyway.
sincity

[chpthril]

Where we at Sarah? Whats the latest?

[sarah.shepherd]

We swapped the optima battery out for a group 29 and made sure the perko was wired properly and our last weekend out we had no issues

We made sure to switch the perko to the 2 spot whenever we were just floating and listening to the stereo.

We're hoping to get one more weekend out on the lake to test it again but so far we're good!! I think we are going to hold off on the alternator upgrade since we are hoping to sell the boat next summer and upgrade.

[chpthril]

We swapped the optima battery out for a group 29 and made sure the perko was wired properly and our last weekend out we had no issues

We made sure to switch the perko to the 2 spot whenever we were just floating and listening to the stereo.

We're hoping to get one more weekend out on the lake to test it again but so far we're good!! I think we are going to hold off on the alternator upgrade since we are hoping to sell the boat next summer and upgrade.

Great....sounds like going with a marine deep-cycle helped a lot.